Caffeine and Running

This post was originally featured on Salty Running.

Caffeine is everywhere these days. It comes in gum, gels, and jellybeans, and even in sprayable cans, powdered form, and, briefly (pun intended), in underwear. And certainly, for many, it comes in the form of a morning cup of joe.

Runners especially seem to cling to the caffeine. After all, training can be exhausting, often taking place in the wee hours of the morning or after a long day at work. We need a jolt to get out the door … and maybe a caffeinated gel to get through the final miles … and maybe another cup to revive us enough to tackle the rest of our jam-packed days ... and then maybe an afternoon latte to stagger through to 5:00.

But there’s a lot of talk about caffeine and whether it’s good or bad for us, especially as runners. Does it give us a boost or give us the trots? Does it dehydrate or replenish? If we drink that morning coffee day after day (along with the afternoon mug) will it still give our run a boost? Below is a summary of what we know about our daily cuppa.

Not exactly unbiased:
 Caffeine contributed to the writing of this post. 

The Good

Caffeine is a known performance enhancer, so much so that it used to be banned by WADA. Caffeine helps reduce perception of effort (it feels easier to nail a fast pace), increases muscle contraction, and ups the circulation of free fatty acids during high intensity workouts, sparing those precious carbohydrate stores. And of course, it perks us up during exhausting training weeks. Many of us couldn’t get through the daily grind without our morning grind. In fact, one reason it’s no longer banned is its ubiquity in our culture; 85% of Americans consume caffeine daily.

The Bad

Sadly, there’s bad news brewing too. If taken before or during exercise, caffeine can reduce blood flow to the heart. This is troubling because the heart is pumping harder during exercise, so it needs more blood, not less. Some speculate this may be a cause of sudden death in marathons, although no death has been specifically linked to caffeine yet. Based on the possibility, the International Marathon Medical Directors Association warns runners not to consume more than 200 total milligrams of caffeine before and during a race. Those most susceptible are people who don’t regularly consume caffeine, have heart disease, or take it in high doses (like those found in energy drinks). If you have heart trouble, please don’t use this post as a reason to start chugging energy drinks. Talk to your doctor first and be cognizant of the caffeine levels in your drinks and gels… and how quickly they can add up.

The (Could Be) Ugly: Bathroom Issues

This could fit in the good or bad categories, depending on your situation. Some runners love a cup of coffee before a run; it gets things moving so there’s no need for a bathroom stop later. Others find it works a little too well in that area and end up with the trots. If you’ve been experiencing bathroom issues on your runs lately, you might consider examining your caffeine consumption and see if adjusting it helps.

One oft-cited con of caffeine is that it makes you pee more often, potentially dehydrating you. Fortunately, this has been debunked in recent years; there appears to be no difference in fluid balance (i.e. urine volume) after drinking water or caffeinated beverages, particularly if you’re a regular caffeine user.

How Much?

To get a helpful performance boost, the recommendation from most studies is 3-6 milligrams per kilogram of body weight. For a 130-pound woman, that’s about 180-350 milligrams of caffeine, or around 12 ounces of strong coffee or three 8-ounce cups of tea. (Note: the high end of this is much more than the International Marathon Medical Directors Association recommends.) More than that doesn’t seem to provide any additional benefit.

Obviously, it’s important to know your body. If you have heart problems, are on certain medications, or are pregnant, you may need to limit your intake. Furthermore, people metabolize caffeine at different rates. A genetic test can tell you if you metabolize caffeine quickly (you get a jolt quickly, but it fades quickly too) or slowly (it takes longer to work, but lasts longer too). But based on your own experience, you probably already know this without knowing your genes. If caffeine takes a while to kick in, you might want to try drinking it an hour or so before the race, while if it hits you quickly, you might try taking a gel just before the start and supplement during.

Do You Need to Give it Up Before a Big Race to Get a Boost?

Some coffee addicts have success tapering caffeine leading up to the race. Since your body is habituated to its daily dose, lowering your tolerance may allow a cup of coffee or caffeinated gel to give you a bigger boost on race day. But some think it’s not worth the misery of withdrawal symptoms when you’re already cranky from tapering. The science is mixed; there seems to be no consensus whether your tolerance matters for performance benefits.

Anecdotal evidence is mixed too. I tried cutting back on tea (my main caffeine delivery system) before my last race, but didn’t sense much difference. But my friend Laura (aka Salty's Barley), an avid coffee girl, has had great success. If you want to try it, she recommends slowly easing off it starting one to two weeks before the race. To counter the withdrawal, she starts by drinking half-caf and then progresses to decaf.

My caffeine delivery system: A cup of tea for T. 

Coffee for Recovery: Is it the New Chocolate Milk?

Consuming carbohydrates along with some protein, like in chocolate milk, after a long workout is crucial to replenishing fuel stores and promoting recovery. But research also shows that combining caffeine with the carbs could give an additional boost. One study found that a post-workout combination of carbs and caffeine led to increased glycogen stores (the energy supply we use up during long runs) a few hours later compared to post-workout carbs alone. Another study found the combo may help runners bounce back after a long workout; people given both carbs and caffeine performed better on a sprinting test a few hours later. (Some caveats: both studies were small and used a LOT of caffeine, equivalent to about 5 cups of coffee.)

Though the research doesn’t seem as robust as for chocolate milk, it is comforting, especially when you're slamming a coffee post-run on the way to work. Who knew that was helping you recover?

In Summary

Overall, the studies provide some good news for coffee lovers to contemplate as they sip their morning mug. But for those new to caffeine, start slowly (perhaps with tea or a gel with 25 milligrams) and if you are at risk for heart trouble, consult your doctor first.

Science Friday: Chasing the Runner’s High

A few weeks ago, my mom asked about advice for a family member who just started running. “She’s complaining she can’t get that runner’s high yet. It’s still not very fun. How long does it take?”

How long of hating running before you love it? How long, despite the sweat in your eyes and the exhaustion in your legs, until you cherish it? Like a morning cup of coffee, you crave it, you need it. Gimme the good stuff. You become addicted to the runner’s high, that feeling where a run becomes relaxing, calming, cathartic. But it doesn't come with every run, and it doesn't start on your first trek out. What causes the runner's high and how can we get it? 

The runner’s high is classically blamed on exercise-induced release of endorphins, the body’s natural morphine, its natural pain relievers. Recently, another class of molecules, endocannabinoids, has shared some of the credit. Endocannabinoids are the body’s natural THC (the active ingredient in marijuana), its natural calmers.

A brief foray into how the thinking has bopped around a bit: Endorphins were initially held responsible for the runner’s high because they could be detected in the blood after exercise. But endorphins are too large to get from the blood into the brain—where they would need to be to affect mood—so their role was dismissed. Some even took this to mean the runner’s high was a hoax. Researchers desperate to prove the runner’s high was real discovered that endocannabinoids are made in the brain following exercise and lead to a sense of calm. Voilà. Endocannabinoids stole the show. But the endorphin proponents would not be silenced. Advancements in neuroscience allowed them to see that endorphins are actually made in the brain as well. The moral of all this back and forth research: endorphins and endocannabinoids deliver a one-two punch. Less pain, more calm. (Also, the runner’s high is real, and don’t tell a researcher who runs that it’s not.)

Back to the main question: how many pills do you have to pop to get the high?

Most of the endorphin research is focused on endorphins in the blood; the more recent discovery of brain endorphins means there hasn’t been much written on the intensity or duration of exercise needed for their release in the brain. We do know that exercising at over 75% VO2max (75% of maximum aerobic capacity) caused a spike in blood levels of endorphins. For cyclists pedaling at about lactate threshold (roughly equivalent to tempo run effort), endorphins increased after 60 minutes.

After an hour at lactate threshold (when lactate is produced and
cleared at an equal level), beta-endorphin increases in the blood of cyclists.

We might speculate that brain endorphins would follow a similar pattern. The study that found endorphin release in the brain only looked at one time point—after a two hour run. Two hours was long enough for the participants to have both a surge of endorphins and good feelings. Below is a graph of how they felt after doing nothing (rest) and after running. Happiness and euphoria increased significantly. Interestingly, fatigue didn’t change at all. (I told you long runs are energizing! Or at least not as exhausting as you would expect.)

VAMS is a scale for evaluating mood. Following a run, levels of happiness
and euphoria were significantly increased compared to rest. 

(Mostly unrelated—but too hard to resist—aside: if you feel so inclined to go for a little bike ride during labor, the ensuing endorphin release can help with the pain of delivery. Let me know how that works out for you.)

Endocannabinoids are released in a similar way. In one study, endocannabinoid levels increased after an hour of running or cycling at a moderate pace. In another study, researchers looked at thirty-minute runs of varying intensities. After a slow jog or a medium intensity run, endocannabinoid levels skyrocketed. However, after a high intensity workout (or an easy walk), there was no endocannabinoid increase. In the paper, the researchers say, “High intensities lead to limited changes in mood or affective state.” I’m not sure I entirely agree with this. Maybe because I have been a running addict for years I have built up quite a tolerance, but I think the really tough workouts can be some of the most psychologically releasing. After they end, of course. 

Luckily, both these molecules get released under the same conditions: moderately intense exercise, a solid tempo or a long run. These also happen to be the workouts that might require an extra push to get through. Our brain senses that and kicks on to give us the good stuff when we need it.

As for beginners, the news is less heartening. It takes a while before you can start grinding out these intense workouts or logging hour-plus runs. Fortunately, other benefits of running (strength, energy, weight-loss, health) may be more immediate. Take comfort that with each run you’re many steps closer.

This week, our family’s newest runner finished her first 5k. I’d say she’s well on her way.

Dream big and keep getting your fix,
Teal

Science Friday: Oxidative Stress is Hot Stuff

In last week’s post, I discussed hot weather training and how its benefits persist even in cold weather; since your body has to work harder in the heat, you are forcing it to toughen up. This translates to improvements that last even when the stimulus is gone. (The same way training at altitude pays off at sea level.)

This week, I came across a study that discusses one of the ways this may occur, i.e. one of the ways heat forces lasting improvements. Here, subjects biked for an hour in different temperatures: 45° (cold), 68° (room temperature), or 91° (called “warm,” but this warm-weather wuss would call that “hot”). Afterwards, the subjects were kept in their temperature-controlled rooms for three hours. (It’s unclear what they were doing for those three hours. They were given dry clothes, something to drink, and got to lay down, which sounds like a perfect recipe for a post-workout nap, but they were periodically poked and prodded by the researchers, so maybe not.) Blood samples obtained over the three hours were examined for markers of oxidative stress. When oxygen is broken down by mitochondria to produce energy (as happens normally and to an increased extent during exercise), reactive oxygen species are also produced in the process. Oxidative stress occurs with the overproduction of these species, which are thought to damage DNA and accelerate aging and disease. (This is why people tout antioxidants, which sop up these species.) In the study, the subjects that exercised and recovered in the warm room had the highest levels of oxidative stress.

But oxidative stress is not necessarily a bad thing. Like weight lifting or running, it causes a stress to your muscles that forces them to rebuild stronger. In this case, oxidative stress encourages cells to make their own antioxidants and increase mitochondria, which make all that wonderful energy. This increase in oxidative stress in the heat may be one of the explanations for the benefits discussed last week. Just like heat demands us to deal with less blood pumping to our muscles, it also forces us to deal with reactive oxygen species. The muscles clean up the mess and patch us back up, better than ever.

I wished the experiment had also examined differences between exercising and recovering in the heat. (A way to test this would have involved everyone first exercising in the heat, followed by half the subjects recovering at room temperature and the other half recovering in a hot room.) Recently, there have been warnings against going overboard on recovery aids. In some regards, the soreness, inflammation, and—in this case—oxidative species caused by a run are a good thing. Ice baths, ibuprofen, or perhaps even cooling off in a comfortable room may cut your body too much slack. The researchers didn’t test that here, but it’s an interesting idea.

Antioxidant supplements have come under fire recently for a similar reason. As I described in a post about vitamin C, taking antioxidant supplements (which contain a much higher dose than found naturally in fruits and vegetables) may block our bodies’ adaptations to exercise. (An interesting take on why fruits and vegetables are better than synthesized pills is here.) Again, it’s a case of overdosing on recovery; trying to force your body to bounce back, when the best improvements are made by letting your body recover naturally, with whole foods, time, and perhaps even a post-run nap in a warm spot.

Dream big,
Teal

Science Friday: Embrace the Heat

It’s mid-July. It’s hot. It’s humid. It’s horrible.

Running in the heat is miserable, as I’ve experienced in a few races and every time summer rolls around. As you heat up, your heart starts beating faster to pump more blood to the skin, where the heat can be released. Sweat rate increases to help cool the skin through evaporation. (The reason humidity is such a nuisance is that the air is so saturated with moisture, the moisture on your skin doesn’t have anywhere to go and the cooling effect of sweat is lost.) Running performance plummets because your heart is working harder than usual, but the oxygen-rich blood is being shipped to the skin, not to your muscles. In addition, sweating can lead to dehydration and electrolyte loss.

Every summer we are reminded what to do to exercise safely: run in the shade, early in the morning, in technical clothes (Dri-fit, etc.); drink water and/or electrolyte beverages before, after, and possibly during runs; and accept slower times or even a workout cut short. We are comforted that after a few weeks (about two), things will get better. Our bodies will adapt by sweating sooner, more aggressively, and forfeiting less salt (yes, being super sweaty is a good thing). The heat won’t annihilate our workouts as much; we’ll be able to go faster with less effort and lower heart rates. We’ll be acclimated.

Yes, a couple weeks in the heat means it’s less terrible to be in the heat. But this news is not preventing me from daydreaming of moving to Antarctica. What does hot weather training have to offer, besides a pile of drenched clothes and a sports bra tan line?

A 2010 study by Santiago Lorenzo and colleagues details an unexpected reward. In the study, competitive cyclists were split into two groups. At the start, both groups endured a number of physiological tests in both cool (55°) and warm (100°) conditions. One group then spent ten sessions riding at an easy pace in a hot room (104°, aka too hot to try this at home) while the other group did the same workouts in a cool room (55°, aka ideal exercising weather). After the ten sessions, both groups were again tested in cool and warm conditions.

A summary of the results is shown in the graph below. As you’d expect, when tested in the heat (black bars) the experimental group that practiced in the heat improved across the board: increased VO2max (the maximal amount of oxygen that can be taken in and used), lactate threshold (the point above which lactate accumulates in the blood; approximately tempo run pace), Qcmax (the maximal cardiac output, how much blood the heart is pumping), and time trial performance. They were acclimated after the ten sessions. The control group that practiced in the cool room was not acclimated to the heat, and the group's scores hovered around zero; they didn’t improve much from the start to the end of the study. Not surprisingly, their time trial performance worsened in the heat.

What was surprising to the researchers were the results from the tests in the cool conditions (white bars). Even under these conditions, the group that practiced in the heat did much better compared to the group that practiced at ideal temperatures. Again, both physiological measures and performance improved in the heat-acclimated group while the cool-training group remained the same. Heat training led to improvements no matter the conditions.

As Steve Magness mentions in his new book The Science of Running, heat training is analogous to altitude training. The stresses our bodies have to deal with in the heat (less blood flow and oxygen to the muscles, similar to training at high altitude) force a number of adaptations, including increased blood volume. In the summer, you get an “altitude-like effect” without having to move to Flagstaff or Mammoth Lakes. (And it might even discourage dreams of Antarctica.) When the weather cools, your body will be stronger and tougher from its heat training.

So embrace the heat (safely). Come September, you might have a shiny new PR because of it.

Dream big and don’t sweat the sweating,

Teal

Science Friday: Vitamin C

In these last days before spring marathons, runners everywhere are obsessing over possible scenarios that could undermine all their training at the last second. They’ve morphed from running junkies to tapering balls of anxiety, stressing about weather predictions, analyzing the carbohydrate content of their food, and constantly washing their hands. This is not the time to come down with something.

I didn’t take enough precautions before this year’s Rock and Roll Half-Marathon. The week of the race my nose started running, my throat itched, my eyes watered. I was sick. In last minute desperation, I overloaded on anything with vitamin C. I drank orange juice, ate red pepper, snacked on strawberries. (Orange juice has a lot of vitamin C, but oranges themselves are not the only source of vitamin C, nor are they the best one.) Unfortunately, I wasn’t cured before the race. Despite a persistent belief that vitamin C can cure a cold, my personal case study (n=1) would suggest otherwise. But what does the real research say? Should tapering marathoners be vitamin C loading?

There are two key words in that question: marathoners and loading.

First, the marathoners. Last year, a meta-analysis (a review of previous studies) examined the effect of vitamin C on frequency, duration, and severity of the common cold. For the general population, it seems that vitamin C actually doesn’t help prevent a cold, but it can help shorten it or make it less unbearable. (This was true for people who took vitamin C regularly; taking a dose of vitamin C once the cold started didn’t help much, which may explain my trouble trying to load up once I was already sick.)

But the results were slightly different when they looked at studies of people under “heavy acute physical stress.” These studies looked at skiers, soldiers training in the subarctic conditions of northern Canada, and—relevant to this blog—ultramarathoners (participants who ran the Comrades Marathon in South Africa, a 56 mile race). In these groups, vitamin C supplementation halved the risk of coming down with a cold. It should be noted that for the ultramarathon group, researchers only analyzed the likelihood of getting a cold in the two weeks following the race. The vitamin C likely helped because races like marathons deplete our immune system, making us more likely to come down with a cold. The researchers didn’t look at prevention of colds during training or before the race, but assuming hard training (especially the last few monster weeks before tapering) could also deplete the immune system, then marathoners especially could benefit from being extra vigilant about vitamin C.

Which brings me to part 2: Should we load up?

Here the answer is: not so fast. Vitamin C is an antioxidant (generally a good thing), but excessive amounts may actually be harmful and have a negative effect on training and performance. The thinking here is that exercise produces reactive oxygen species. (Caused by the break down of oxygen, reactive oxygen species build up when cells are stressed, and are generally a bad thing.) These “bad” species may actually help induce training adaptations by forcing the muscles to make their own antioxidants and increase mitochondrial growth. In one study, researchers looked specifically at female runners. (Because of estrogen, there may be gender differences in regards to vitamin C effects.) The runners were given either vitamin C (1000 mg daily, 10 times the recommended amount and the equivalent of 12 oranges or 1 Naked Power-C Machine bottle) or placebo during three weeks of training, and then tested twice: a timed 5k and a treadmill test where the speed and incline increased until exhaustion. Vitamin C seemed to decrease the speeds they could hit in practice (during training), but didn’t seem to significantly help or harm the speeds on “race” day (for the 5k and the treadmill test). (It seems possible that not being able to go as fast in training would eventually catch up to you on race day; I wonder if the study was too short to investigate that.) The researchers also measured markers of oxidative stress (those bad species) and found they were higher when the runners were taking vitamin C. The differences here were small, but it suggests a level of caution. 

Just to add another degree of confusion to this debate, vitamin C is water soluble, which is a fancy way of saying that if you take too much, you will pee out the excess. However, overdoses—although rare—can happen and as the above study suggests, excess isn’t entirely harmless.

So the lesson is that regular vitamin C could possibly prevent a cold when your body is depleted (i.e. before you start the taper). Too much vitamin C might prevent training adaptations, so it may be best not to go overboard with supplements and Naked drinks and just adhere to the old standard of Moms everywhere: eat your fruits and veggies.

And keep washing your hands.

Dream big and stay healthy,

Teal

Science Friday: A Good Night's Sleep

Exercise helps you sleep—that's not particularly shocking. And most runners aren't surprised to hear of its role in stress relief. So it stands to reason that when you're so stressed out that you're tossing and turning at night, going for a run could provide a double benefit: less stress and more sleep.

Monika Fleshner's group presented data at the Society for Neuroscience Conference in San Diego (a great place for a run—stressed or not) that investigated, in a number of ways, the relationship between exercise, sleep, and stress. One study, led by Robert Thompson, a PhD student at University of Colorado-Boulder, asked if exercise could help stressed rats sleep better. Half of the rats were able to run on a wheel, while the other half remained sedentary. (The rats weren’t forced to run, but were given access to running wheels in their cages and could run as they pleased. Rats voluntarily run about 5K each night.) After six weeks, the rats were stressed with shocks to their tails. Their sleep/wake cycles were studied both before and after the stress.

Before stress, exercised rats spent more of their time in REM sleep—the stage of sleep when dreams occur—compared to non-exercising rats. Directly after the stress, all the rats had a rough time sleeping—they got the same amount of REM sleep whether it was day or night. But by the very next day, the running rats were able to recover their sleeping habits. The sedentary rats struggled for a few more days.

But rats are rats, what about people?

Most of the studies on people (described here, here, and here) don't look at stress, but agree that running helps sleep in general. In contrast to rats, however, exercise decreases REM sleep in humans, while increasing non-REM sleep (including deep sleep). When looking at people who have trouble sleeping, like insomniacs, exercise takes longer to have an effect. But the moral of the story is the same: exercise will eventually help you sleep, no matter how stressed.

Another interesting story from the Society for Neuroscience conference: When asked if mental games (like crosswords) or exercise is better for brain health, scientists agreed that the jocks win. So put your crossword down and go for a run! If nothing else, maybe you’ll get a better night's sleep instead of tossing and turning over the answer to 7 Down.

Dream big and sleep well, 

Teal

Science Friday: The Ten Percent Rule

As I recover from an injury the questions loom: What caused this? Will I make the same mistake again? Was  "too much, too soon" to blame? I've admitted before that I sometimes break the ten percent rule. Is that where I went wrong?

The ten percent rule--that the safe, injury free way to increase mileage is by ten percent each week--is repeated often by running experts and in training books. It's simple, concise, and easy to remember. But is it true? What does the science say?

Unfortunately for ten percent rule advocates, the science isn't on their side. There aren't many studies that examine the rule, and, to date, none that agree with it. The study that is often mentioned as the best test of the rule was published in 2008 by a group in the Netherlands. 

The participants in the study were 532 novice runners that signed up for a four mile race. The researchers divided the runners into two groups, carefully accounting for past history of sports and previous injuries. The control group was assigned a "frequently used beginners training program" that was 8 weeks long, with an average weekly increase of 23%. (The increases each week varied greatly and included a down week.) The intervention group was assigned a more gradual program that was 13 weeks long, and carefully increased the time spent running by ten percent each week. (One week had only a 2% increase but the rest were pretty consistent.) Both groups were to run three times a week.

The injury rates were shockingly similar. In the control group, 20.3% of runners became injured. In the intervention group, 20.8% were injured. A gentle ten percent increase didn't help.

(Not entirely relevant but interesting: They followed up their work with another study looking specifically at a preconditioning program. Prior research suggested that people who participate in sports that involve jumping and pounding to the joints (soccer, basketball, or volleyball) get injured less often when they start to run than those who participate in sports with less pounding (swimmers and cyclists.) They designed a four week program that simply included a few sessions of hopping mixed with walking. The preconditioning/hopping program was completed before the running program began. The hopping had no effect on running injuries, however, as the control group and the hopping group were injured just as often.)

Recently, a smaller study was published using GPS watches to track increases in mileage. The authors wanted to do away with the subjectivity of subjects self-reporting how far and fast they ran, so they gave them Garmins (Forerunner 110s), asked them to run for ten weeks, and tracked their injury rates. The Garmins couldn't lie: runners who became injured tended to have a greater weekly increase in mileage. But the increases--for healthy and injured--were higher than ten percent; injured runners increased mileage an average of 32% while runners who remained healthy increased mileage by 22%. The difference between the two groups' mileage wasn't quite statistically significant, however, which means that while it's interesting, it's not quite enough to make sweeping generalizations. They also calculated that injured runners had a large (and significant) jump in their mileage the week before symptom onset, with an average increase of 86%*. It may be surprising to the ten percent folks that people can get away with greater than 20 percent increases and remain injury free, but injury following an 86% increase isn't terribly shocking.

The authors of the GPS study summarize nicely: "No clear evidence for safe progression of weekly volume exists." The ten percent rule may be convenient, but it's not accurate. In fact, some people can safely increase weekly mileage over 20 percent and remain healthy. But others (1 in 5 in the first study) get injured even with an increase of just 10 percent. It seems like it's up to you to know your body and what it can handle, which unfortunately is learned by trial and error (and injury.) It's probably best to err on the side of caution, and maybe not try to bump up by 86% in one week. 

Dream big, 

Teal

*It should be noted that the number of participants in this study was small, and the number of injured was even smaller, only 13. So while this may seem like a high number, it's probably because of the small number of people. 

Science Friday: Diagnoses and Discoveries About Hips

Note: This is not a typical Science Friday, but Part 2 in the unexpected series identifying what is wrong with RunnerTeal.  (Let’s hope for no Part 3 anytime soon.) 

Last week I told you about my not-so-hip hip and my upcoming doctor’s appointment.  Everyone’s well wishes and thoughts paid off, as I do not have a surgery-requiring labral tear, but tendonitis in my hip flexor instead. (Yippee!!) Tendonitis means no running for a few more weeks, being forced to confront my hatred for biking, and no fall marathon. (The Philadelphia Marathon has now stolen my money for the last two years. I’ll get you back some day, Philly…) But, it isn’t surgery, and that is a huge relief that indisputably makes a few run-less weeks and hours of boring biking seem like a blessing.

Given the crash course I’ve had the last few weeks, I thought it might be nice to share some of the things I’ve learned about hips, both their tears and tendons.*

The hip is a ball and socket joint, like the shoulder, where the head of the femur (the ball) sits in the pocket (called the acetabulum, the socket) of the pelvic bone. This allows for motion in almost all directions and allows us to walk, jump, and of course, run. It absorbs a lot of forces; when we run, the forces are many times our body weight. The hip is the superstar of joints.

The acetabular labrum is the cartilage that surrounds the socket, helping to keep the femur securely in place. Running repeatedly over years and years (as marathoners are wont to do) can cause the labrum to wear thin and tear. (This can also occur more instantaneously in contact sports or accidents.) The pain occurs on the inside of the hip and it may present as stiffness and tightness or it may feel like it’s clicking or catching. The latter is the symptom that had me (and Dr. #1) convinced I had a tear. If the tear is bad enough, arthroscopic surgery may be required, where the torn portion is cut out. After seeing my x-ray and hearing my description—when the pain was worst, what time of day it hurt, etc.—my doctor was less than convinced that I had a labral tear, and did an ultrasound to check. If I had a tear big enough to need surgery, he’d see it on the ultrasound. Fortunately, he found a healthy looking labrum! He diagnosed me with tendonitis of the hip flexor instead.

The hip flexors are a collection of muscles that mainly function to pull the leg and knee upward, towards the body. Two of these muscles, the iliacus and the psoas major (together referred to as the iliopsoas), are the most susceptible to hip flexor injuries, and tendonitis can occur in the tendons associated with these muscles. (Tendons attach muscles to bones.) When under repeated stress, tendons can degenerate and become inflamed. (The suffix “-itis” means inflammation.) The stress could come from doing too much too soon or from overuse, pushing too hard for too long—again as marathoners are wont to do. If the tendons are inflamed or aggravated, most likely the surrounding muscles are as well. During my appointment, the tightness and stress on these muscles was obvious. The psoas major connects the lumbar part of the spine (the lower back) to the front of the pelvis. When my doctor pressed on my lower back, I could feel pain in the front of my hip—a strange sensation that convinced me he knew what he was talking about. (An interesting side note: only about 50% of people have a psoas minor. It seems not to matter whether you do or do not have this weak muscle.)

Treatment for tendonitis includes anti-inflammatories, physical therapy, massage, and, of course, the most hated treatment: a break from running. The tendon is able to heal itself; the purpose of the initial inflammatory process is to promote healing. As with all injuries, the trick is patience: let your body work its magic (and have a really good PT to help coax it along.)

Here’s a quick run down of other hip issues that affect runners:

Bursitis:

Bursae are lubricating sacs that cushion areas where muscles and tendons slide against bone; bursitis is an inflammation of these sacs. Trochanteric bursitis will cause a dull ache or rubbing on the outside of the hip. Again, the treatment includes rest and ice/anti-inflammatories.

Stress fracture:

In the hip region, the most common place for a stress fracture is the neck of the femur. A stress fracture causes a throbbing pain that gets worse with more running and will probably leave you limping. If you can’t hop on the affected leg, a stress fracture is probably the issue, and you should immediately stop hopping and stop running. Here the treatment is 6-8 weeks of no running.

Iliotibial (IT) band syndrome:

This can present as a jabbing pain on the outside of the knee, but it starts up in the hips. IT band syndrome is from irritation of the ligament that runs along the outside of the thigh from the hip to the shin. You can get it from doing too much too soon (always trouble!) or even from running the same direction on the track (too many left turns!) IT band syndrome can be helped with rest, ice/anti-inflammatories, and massage before starting a program that strengthens the surrounding muscles.

Piriformis syndrome:

This is literally a pain in the butt, as pain shoots from the butt down the back of the leg. It can be treated with massage and physical therapy.

Staring at images of skeletons, muscles, and joints and learning all the things that can go wrong makes me appreciate how amazing it is that, most of the time, things work smoothly to allow us to move around. And, someday soon, to run again.

*Note: I am not a doctor, just a scientist who likes to teach herself things. You should see an actual doctor if you’re having hip trouble.

Dream big, 

Teal 

Science... Wednesday(?)/Shameless Plug

Much to the chagrin of my Science Friday fans, most of my science writing this summer has been concentrated on my internship at NOVA, where I contribute to the NOVA Next website. This week I wrote a feature about focus in sports and devoted half of it to discussing focus in running. (Interview people about running marathons for my day job? Yes please!) Get a dose of Science Friday Wednesday and check it out here.

But first, a warning! There is a spoiler; if you haven't read my Charlottesville Race Reports, I suggest (in a completely non-biased way) you read Part 1 and Part 2 before the NOVA piece. 

Hopefully I'll have some real Science Fridays finished soon!

Dream big,
Teal

Science Friday: High Fat Tapers

We all know about carbo-loading. A couple days before the marathon, we suppress our tapering woes with heaps of carbohydrate goodness. There’s a lot of research behind it and so inevitably the Italian restaurants on marathon weekend are teeming with runners.

But what about a few days before the carb-fest begins? I’ve heard that the week before is a good time to make sure you’re eating healthy fats. What’s the logic behind this?

The idea is to get the body to oxidize (i.e. break down and use for energy) fat more than glycogen (that precious molecule we so carefully try to stock up and save). This can be achieved to some extent with training; the more we train to become endurance athletes the more we teach our bodies to use fat. But can we help out by eating a high fat diet?

There’s a lot of research into this idea; the problem is not all the studies agree. Some use long periods of fat-loading (seven weeks!), some only a few days. Some use different percentages of calories from fat, some look at endurance, others at speed... it’s hard to know what to think. 

I looked up the article that’s often cited for the recommendations I’ve heard. In this study, the researchers had well-trained cyclists eat 10 days of a high fat diet (>65% of calories from fat, see below for an example day), followed by 3 days of typical carbo-loading (>65% calories from carbohydrates). They compared this to a separate trial where the same subjects ate their normal diet followed by 3 carbohydrate filled days. They had the subjects bike for 150 minutes before completing a 20 km time trial. The high fat diet increased fat oxidation and decreased oxidation of muscle glycogen, as the researchers hoped. Moreover, when the cyclists had eaten the high fat diet, their times for the time trial were slightly (but significantly!) faster.

A fatty day!

So this study suggests 10 days of high fat diet followed by the typical carbo-load helps improve performance. The inclusion of the carbo-load is important; studies that don’t include it often don’t see any benefit from the high fat diet. It seems like without the carb-fest, the fat-fest won’t work. You always need to eat that pasta.

Now available in
stores research labs.

One thing that jumped out at me was that they also gave the subjects easily digestible fat solutions just before the time trial and a combination of digestible fat and carbohydrates during the trial. I picture a fatty version of GU. The authors say this was done to maximize potential fat and carbohydrate oxidation during exercise, but they don’t have any controls to see if this is necessary to reap the benefits of the high fat diet. I've never eaten any fat during a race, so I wonder the real world relevance of this.

I’m fine with eating some healthy fats (bring on the guacamole!), but I don’t know about 65% of my diet from fat. That seems like a lot of fat at a very delicate time in the lead up the marathon. It’s certainly an interesting idea, and I’ll keep a look out for more studies. In the meantime, has anyone tried this drastic of a pre-race diet?

Dream big,

Teal

Science Friday: Stress-ercise

I've been a little stressed lately. There's work, wedding planning, and plenty of workouts, enough to make anyone a little crunched for free time. Some people's response to my hectic life is to suggest I give up running. I have to work of course, and the wedding will be the wedding of the century. (She says without a hint of Bridezilla in her voice.) But running, that's just for fun. Why add any unnecessary stress?

My response is always something along the lines of running is my stress release. Sure, as the Big Race gets closer it can seem quite the opposite, but in general, running keeps me sane. Even though it robs me of mornings spent sleeping in, late nights socializing, and lazy Sundays, I love it. I'd rather metaphorically run around a little hectically than literally not run around at all. 

But it has got me thinking, is there a point where the pressures of lots of miles, big races, and goals of PRs negate the stress release provided by a daily jog? What if it starts to feel like just another item on a long to-do list?

An interesting article came out recently about forced exercise--if you really hate exercising but your doctor or gym teacher is making you, do your stress levels still benefit? Or does the agony of it all just lead to more anxiety? To address this, the researchers used rats forced to run on treadmills and on running wheels. Previous research has shown that rats forced to run on treadmills don't have the same reduction in anxiety as rats that voluntarily run when they please on a wheel. (Rats: I totally understand your perspective here. Treadmills stink.) Was it the forced nature of the running? Or was the treadmill running just unnatural for rats? Rats tend to run in intermittent bursts, so the researchers rigged running wheels to do the same. (I.e. the wheels rotated quickly for a few minutes then stopped for a bit before starting again, uncontrolled by the rats.) Another group of rats ran on wheels whenever they wanted, a third group was forced to run continuously on a treadmill, and a final group did not exercise. After six weeks, the rats were stressed by a standard rat-stress-paradigm (shocks to their tails.) The rats’ behaviors following the stress showed the no exercise group and the treadmill group were the most anxious. The voluntary wheel runners had less stress (as expected), but interestingly, so did the forced wheel runners. Even though they were being told when and how to run, their anxiety levels still went down. The take-home: even forced exercise (doctor, gym teacher, or Jillian Michaels prescribed) is better for stress relief than no exercise. (Provided the exercise isn’t “unnatural” for humans.) Also, treadmills are the worst. (See previous comment about unnaturalness.) 

Of course I don't feel my running habit is forced upon me. I do it because I love it. But it’s nice to know that even on those days when it might feel like another chore, it is actually helping me relax. But if I was really pressed for time, would it help to give it up for a little while? 

A different study hints at the answer to that question. What happens if exercising mice stop exercising? Do they return to baseline (the same as non-exercising mice), or do things get worse? Here there were three groups of mice: mice that exercised for three weeks, mice that did nothing for three weeks, or mice that exercised for one and a half weeks and then did nothing for one and half weeks. Continuous exercise reduced some measures of anxiety, but the group that stopped exercising looked the same as mice that never exercised. On other measures, the exercise-quitters were worse than the ones who never exercised. The authors suggested these could be withdrawal symptoms; maybe the mice were addicted to running. Finally, the authors measured the number of new neurons in the hippocampus. (Exercise has been shown to increase neurons in the hippocampus, an important area for memory.) Once again, the mice that kept exercising had the most, while the non-exercisers and exercise-quitters looked the same. The take-home: Reducing exercise can increase anxiety, negating any benefits from previous exercising. So no, you shouldn't give it up even (especially!) if you're feeling stressed. 

Remember, these are rodents. But from my own human experience, I almost always feel better after a run. Maybe it's because I've already checked one item off my day’s to-do list, making the others seem do-able as well. Maybe it's because I’ve got new neurons in my hippocampus and endorphins in my bloodstream. Maybe it’s because I love running, even when it’s hard to fit in my schedule.

The take-home: I'll keep on running and not stressing about it.

Dream big,

Teal

Science Friday: For the Love of Chocolate, Bite Two

Happy day after Valentine’s.

I’ve crawled out of my chocolate-induced coma to bring you the second annual installment  of Chocolate Is Good For You News.  This study came out last year, too late for Valentine’s but in time for Easter. (Do I need to start having an April edition of CIGFY News to justify my Cadbury egg consumption?) It doesn’t have anything to do with running or exercise, but it’s chocolate, so I couldn’t resist. (As is usually the story with me and chocolate.)

In this study, they asked over a thousand people about their eating and exercise habits, evaluated their BMIs (Body Mass Index, a ratio of height to weight) and mood, and most importantly asked the age-old question, “How many times a week do you consume chocolate?” (More than you’d like to know, Researcher. More than you’d like to know.) As you might expect, they found that people who ate chocolate more frequently consumed more calories overall, including more saturated fat, and had higher rates of depression. But they also found that people who ate chocolate more frequently had lower BMIs. (Emphasis is theirs. Even they were so surprised by this that they had to add italics.) They found no link between chocolate eating and exercising. 

What’s really remarkable about this is the issue of calories. There’s an idea that a calorie is a calorie, meaning that no matter what you eat, if it adds up to more calories, you’ll gain weight. Of course that’s overly simplified. Studies show some calories are better or worse than others: protein has been shown to keep you lean, monunsaturated fat to reduce your risk of heart disease, trans fat to raise your risk. Most people would put chocolate in the bad calorie column; it’s full of sugar and fat. But this study suggests it’s not so bad; that a chocolate calorie isn’t just a (delicious!) calorie. Even though chocolate lovers ate more calories, they were still thinner. The authors cite other studies that have found chocolate helps regulate insulin sensitivity, blood pressure, and cholesterol levels. Maybe these advantages of chocolate offset the sugar and fat. The authors finish by concluding that a randomized clinical trial of chocolate may be needed. Count me in!

Unfortunately, the researchers didn’t ask about the type of chocolate. Dark chocolate gets all the good press and is getting more popular, but considering the ubiquity of milk chocolate products in our supermarkets, I can’t imagine these people were eating only dark chocolate. It would have been interesting if they had included that distinction, especially if it gave some credit to poor old milk chocolate. 

Dream big,

Teal 

Science Friday: Hunger Games

The link between exercise and weight loss is controversial. Lots of studies and personal testimonies (yours truly included) indicate that exercise leads to weight loss, but there are other studies that swear it doesn't. (Some studies just throw everything you thought you knew on its head.) I've talked before about the idea of "fit and fat;" it seems that even people who may not experience weight loss still experience many healthy benefits of exercise. But what's the deal with the lack of weight loss? Of course exercise burns calories; one worry is that people over estimate what they burned and overeat, consuming more than they lost. Also, exercise makes us hungry. (See my current amount of food consumption, which has sky rocketed with marathon mileage.) 

An interesting recent study investigated the link between hormones released before and after an exercise intervention and the amount of food eaten. The hormones studied (CCK, obestatin, GIP, and leptin) help to regulate your eating; CCK and leptin tell you to stop eating, GIP tells you to eat more. (Obestatin's role remains controversial.) Obesity may disrupt these hormones' ability to accurately regulate food intake. For example, some obese people have high levels of leptin but seem resistant to its effects. (Leptin should decrease eating.) Some evidence suggests that exercise can help get these hormones back in check, which should help prevent overeating and improve weight loss.

In this study, both male and female overweight participants underwent a 12 week exercise program. Before and after the program, hormones levels were measured after fasting overnight and then directly after breakfast. Other days, participants were given a milkshake and then treated to a pasta lunch. (Milkshakes and pasta? Count me in!) The amount of pasta eaten and the amount of food consumed for the next 24 hours was assessed. The trick was the milkshake: one day it was filled with malodextrin, a mostly flavorless substance that more than doubled the calories. Another day malodextrin wasn't added. The researchers asked how the milkshake affected the rest of the day's eating. Will the participants' bodies sense the extra calories and eat less after the megacalorie milkshake? Will an exercise program help?

First of all, the participants lost weight in the exercise program. That's an important note because it's more evidence that exercise can lead to weight loss, even though the participants were told to maintain their normal diet throughout. After the exercise intervention, leptin levels were decreased during fasting and remained decreased after a meal. This may seem counterintuitive, but leptin decreasing with exercise may help the body become more responsive to its effects. (Remember, obese people may have too much leptin and be insensitive.) The milkshake and pasta lunch combination didn't change after the exercise program. Both before and after the exercise program, the participants ate less pasta after the megacalorie milkshake than after a normal milkshake. However, their food intake over the course of the day changed: after the exercise intervention, the mega milkshake led to less food eaten the rest of the day. (Prior to the intervention, the mega milkshake actually led to more food being eaten the rest of the day, see graph below.) This indicates that the exercise program helped to regulate the body's ability to count calories. It's not that exercise makes you eat less (the days with a normal milkshake had increased food intake compared to days before the exercising, compare hatched bars below), but that your body is better able to judge how much you're eating and when you've had all you need.

 Before the exercise program ("All-Baseline," at left) the participants ate more after the mega milkshake (HEP, solid bars) than after the normal milkshake (LEP, hatched bars). After the exercise program ("All-End", at right), they ate less all day following the mega shake.

It's important to note this study looked at participants who were overweight to start with. Previous studies on this subject tested normal weight people, which isn't as relevant to the population of dieters these studies aim to help. The good news for people trying to lose weight with exercise is that exercise may get your body to help out, by teaching it to better regulate eating.

Lastly, the study is an important reminder to know what you're eating. Restaurants (and researchers!) can trick you into consuming way more calories than you may be aware of. This study suggests your body might be able to compensate to some degree, but do yourself and your body a favor and eat fresh and homemade whenever possible!

Dream big, 

Teal

Science Friday: Days to Your Life

“I don’t run to add days to my life, I run to add life to my days.”

That quote is catchy and memorable because the first part is expected; we know that running and being active makes you live longer. The point of the quote is that it goes beyond that.

But today let’s focus on that first part. How many days are we talking about, really? Research recently published in PLOS Medicine attempted to quantify that number. The authors pooled findings from a couple of large studies (such as the Women’s Health Study and the NIH-AARP Diet and Health Study) and accumulated data on close to 650,000 people. The studies included reports from a ten-year follow up and so the authors were able to correlate amounts of exercise with how long people lived. A quick perspective to understand the numbers on the graph below: physical activity was quantified as metabolic equivalents (METs); 7.5 MET-hr/wk is roughly equal to 150 minutes of brisk walking per week, or 75 minutes of vigorous activity (such as running.) 7.5 MET-hr/wk is about the recommendation doctors and public health advocates encourage for a healthy lifestyle.

In the graph, you can see that as "leisure time physical activity" (i.e. exercising in your free time, such as running or walking) increases, years of life increase as well. As you can tell from the sharp increase to the left of the graph, just getting off the couch for an hour or so each week helps a lot. (Activities such as brisk walking for 75 minutes/week increased life expectancy by 1.8 years.) People getting the recommended amount of exercise (150 minutes of walking or 75 minutes of running) increase their life expectancy by 3.4 years. Incredibly, although the effect lessens, it keeps going up with more activity. (No, marathoning likely won't kill you.)

The study goes on to talk about the relationship between BMI, physical activity, and longevity. This is the relatively new concept of being “fit and fat.” Annoyingly, some people can’t seem to lose weight despite a rigorous and routine exercise program. Are these people better off health wise than those much hated skinny people who never have to exercise? So far, the research says yes: even if you don’t lose weight, exercise has other (perhaps less superficially obvious) benefits to your health. So fit and fat people are better off than those inactive, normal weight people (the lean and lazy? skinny and slacking? slim and slothful?)

This study provides more evidence. Overweight people (BMI between 25 and 29.9) who were active lived 4.7 years longer than inactive, normal weight people (BMI between 18 and 24.9.) Even active obese people (BMI between 30-34.9) lived 3.1 years longer than those lean and lazy people. However, this effect disappeared when people had BMIs greater than 35 (severely obese category.) It seems that at that point, the health risks of being overweight outweigh (no pun intended!) the benefits of working out.

In summary, it tells us what we already knew: running can add days to our lives. Now we know just how many: approximately 1,241 (3.4 years) for 75 minutes of running per week. But the life added to our days? That’s harder to quantify.

Dream big,

Teal

Science Friday: Team Training

As you know, a few months ago I decided I needed to change things up and start training with a team. That team has helped in all the expected ways (faster workouts, inspiring role models, great camaraderie) and a few unanticipated others (first hand ferritin knowledge, wedding planning advice). But this week I came across another reason why working out with a team is better than going it alone.

In an article published in 2009 (and referenced in this week’s NYTimes blog about laughter), a group in England investigated the pain threshold in rowers who worked out either in teams of six or by themselves. They used pain threshold as a corollary for endorphin levels; the higher the pain threshold, the higher the expected endorphin release. (Endorphins are the molecules responsible for exercise's euphoric and pain suppressing effects, aka "runner's high.") Collegiate rowers each performed two tests on a stationary rowing machine: one rowing alone and one in the presence of teammates. The length of time and the power output were the same for both tests, so the other teammates weren't actually helping the work load decrease. To measure their pain thresholds, the rowers' ability to tolerate a blood pressure cuff being inflated on their arm was measured before and after the workout. As expected, they tolerated pain better after the workout than before. Gotta love those endorphins.

What’s interesting was that the rowers also tolerated pain better when they worked out with a group. Besides having teammates that hold you accountable and push you to work harder to keep up with them, teammates also make you feel less pain. It seems that the loneliness of the long distance runner rower is a more painful path. The authors speculate that "synchronized physical activity" helps boost levels of pain relieving molecules and this may promote bonding among group members. Anyone who has survived a hard track workout with a group already knows it bonds you. And now it seems your pain tolerance is the better for it too!

Note: Don't worry! I did survive the Army Ten Miler this past weekend and you'll hear the whole story if you tune in next week. I just couldn't resist a Science Friday this week.

Dream big and with friends,

Teal

Science Friday: Diagnosis and Discoveries about Iron

This week I finally got the results of a blood test to determine if low iron was the culprit of my running funk. At first glance it seemed like everything was fine. My doctor told me I had normal iron and hemoglobin levels, but could be maybe, possibly, considered borderline anemic because of low ferritin. She suggested an iron supplement but then proceeded to tell me she thinks I am just running too much. Ah yes, well if I wasn't running, I wouldn't be in here complaining about how my running is going poorly. True, but irrelevant for a die hard runner.

After leaving her office I immediately Googled ferritin (ahh, Google, every doctor’s nightmare.) I remembered an article I had read a while ago about Stephanie Rothstein having iron issues. I discovered that her issue (eventually attributed to celiac disease) had been low ferritin as well. According to the article, normal levels are 20 nanograms/milliliter, but runners actually need more, in the range of 30-40. Rothstein’s was 4 ng/mL. Mine was 6 ng/mL.

Why did Rothstein's doctor suspect that was an issue while mine seemed doubtful? More Googling (and some more sophisticated scientific "Googling") ensued. Why do runners have iron issues? What the heck is ferritin? Could low ferritin be my problem?

Runners need iron to produce hemoglobin, which is the molecule that carries oxygen to your muscles. Without it, your muscles can’t function as well, so you can’t run as fast, you feel more tired, etc. The problem is runners lose a lot of iron. To start with, iron is hard to absorb.We only absorb 15% of the iron we eat; the best (and most easily absorbed iron) is from animal sources like red meat. If you choose not to eat a lot of red meat, like me, that can start the problem. (Good plant sources of iron include beans, nuts, bran, and spinach.) Absorption is inhibited by calcium, coffee, tea, and anti-inflammatories, all of which runners, as a whole, consume a lot. We lose iron through sweat (which can be worse in hot, humid conditions) and through GI stress. We also lose iron through foot strike hemolysis, when blood cells burst from the force of impact with the ground. Women are more likely to have iron deficiency anemia because of blood lost through menstruation.

Ferritin stores iron; most of the iron in our body is bound to ferritin. Less ferritin in your blood means less stored iron. According to some data, low ferritin levels is the best indicator of iron deficiency. However, by definition, anemia is diagnosed by low hemoglobin levels, which is why I am technically not anemic and why my doctor is less than concerned. But then I found this from an article by Coach Jeff Hess in Track and Field News:

Anemia, clinical iron deficiency, is not rare among runners, but even more common than iron deficiency is "iron depletion" due to low ferritin stores... It is common among distance runners to have acceptable hemoglobin and hematocrit counts even when ferritin levels are severely depleted. For less active people, low ferritin levels are much less significant and don't often draw the attention of medical professionals.

So your average doctor might not think anything of it, while a sports medicine specialist might notice the red flag. The symptoms of iron depletion are similar to iron deficiency and include abnormal exhaustion, slow recovery, declining performances, heavy legs, loss of motivation, etc. This was sounding all too familiar and the statistics gave me some validation: one doctor suggested that if ferritin dips below 20 ng/mL, performance begins to suffer. Worse yet, injury rates double when ferritin is less than 20 ng/mL and triple when less than 12 ng/mL.

One study had some good news. Iron deficient female runners were split into two groups: one given an iron supplement and the other a placebo. While the placebo runners continued to experience a drop in their performance, the iron supplemented runners improved. But the catch is it usually takes 2-3 months for iron to right itself; you can’t pop a pill or eat a big steak and feel better in the morning.

Warning: Excess iron is also not a good thing and can have far worse consequences. Before taking a supplement based on suspicions, get a blood test (make sure you specify ferritin to be checked as it isn't always reported) and discuss it with your doctor. A study found that among male marathoners, <2% had iron depletion, but 15%  had signs of excess iron. (On the other hand, 28% of female marathoners had iron depletion, <5% had signs of excess.) In addition, iron supplements are notoriously hard on your digestive system so ask your doctor for suggestions that may work for you. (My doctor suggested Vitron-C.) 

At first I thought I was grasping at straws but, as the evidence piled up, this seems like a common issue, especially among women runners. I had been thinking it was all in my head, that I just needed to stop being a wuss and toughen up. It may be a placebo effect (except I haven't even taken the pill yet!) but having a possible explanation and a plan of attack makes me feel better already.

Special Announcement: Do you enjoy Science Fridays? Do you live in the DC area? If so, come hear me talk about exercise and the brain on Tuesday, October 23 at 7:00 pm at the MLK Library. I’ll be discussing how running cures diseases, slows the aging process, and makes you feel all around spectacular—things you surely already know, but I can give you the hard facts for the next time your coworker says running is bad for your knees. More information about the series Hot Topics In Health Science here.

Dream big,

Teal

P.S. Shout out to the Flexatarian Filly for suggesting this months ago. It planted a seed, and I finally listened. Thanks!