Friday, April 11, 2014

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,

Wednesday, April 9, 2014

My Other Marathon

In between my morning runs and evening carbo-loading sessions, I am a scientist. Or, at least, trying to be one. I have spent the last five years working towards a PhD, the two years before that working towards getting into a PhD program, my undergraduate years working towards getting a job that would get me into a PhD program... All the way back to elementary school adventures with exploding volcanoes, science fairs, and cakes decorated to look like animal cells. (The mitochondria were delicious.)

My first science fair. Told you I was a nerd.
People tell you that a PhD program is so hard, that it really takes something out of you, demoralizes you, makes you dig deep into reserves you didn't know you had. 

I thought, whatever, I'm a marathoner. I can do this. 

But they were right. 

Years of failed experiments. Committee meetings where the end seemed further and further away. Countless days that ended in tears. 

I wanted to give up and quit. Why am I doing this to myself? At one point my dad tried to put an end to my complaining, reminding me that no matter what, "You will never give up now." The defeated voice in my head silently responded, "Oh yea, watch me." I was so close. But no one--husband, family, friends, teammates--would let me.

So I kept going. 

Up the hill. Exhausted and demoralized 20 miles in. Aching to drop out, sit down on the curb and end the misery. 

Slowly milestones ticked off and things came together. This past January, my committee gave me permission to set a defense date. The end was in sight. And yet, there was still so much to do: write up five years of results, present the data in front of the department, friends, and family, and respond to an onslaught of questions in such a way that would convince people I deserve those extra three letters at the end of my name.

"Good for you! You've spent six months training for a marathon! Now you just have to run 26.2 miles, in a row, and you can really celebrate."
"Congratulations! You qualified for Boston! Now run 21 miles, climbing three hills, and then take on Heartbreak. Oh yea, and then 5 more miles."

The end is near, but no celebrations yet.

As the morning of the defense neared, I took all pre-race precautions. I tried to get my sleep, eat well, and eliminate any possible last minute mishaps. When the day came there was nothing else I could do. Time to pray for a favorable tailwind and no mid-race nausea.

The defense was terrible and awful. Like the final miles of any marathon, as soon as it got tough, I ached and mentally pleaded for it to end. And yes, there were moments when I wanted to throw up.

But by midday, it was over. I had done it. It is taking a while to set in, that this Huge Life Moment I ruminated about almost constantly for more than 5 years has finally come and I can stop stressing about it. There were so many moments when I thought I might not make it. But no, I did not DNF. I finished.

Nearly two decades later, explaining something
slightly more complicated on a slightly bigger scale.
And now for the sappy part, to justify a post complaining about graduate school on a blog dedicated to running:

Everything worth doing has a 20-miles-in-and-I-want-to-drop-out-and-curl-up-in-the-fetal-position Moment. (Or many moments, because it doesn't magically get easier at mile 21.) Moments of doubt, of panic, of hating your previous self for signing up for this torture. Find the person/people that will push you, that will hold you up when you want to sit down/pass out/give up. Keep going. Keep fighting. Up the hill and over the other side. Through the finish line. You'll get there.

And then you can really celebrate.

Dream big, 
Teal, PhD