Friday, February 22, 2013

The Experts Weigh In: Eating for Fuel


I feel like I’m living a double life - a double exercise life. My gym routine and my running routine are at odds with each other. Well, actually, it’s just my gym routine that has beef with my running routine (my running routine is secretly in love with my gym routine because she makes me faster on the pavement). Oh, unrequited love.

For the past 15 months I’ve worked rigorously with a trainer who has a strong belief that high protein and low carbs - paired with heavy weight lifting endurance sets (think Crossfit, Tabata, RFT, AMRAP) - are the key to being in the best shape of your life. Her workouts and methodology helped me shed 10 pounds and 5% body fat in the first 6 months (and maintain it).

For the past 8 months I’ve ALSO been hitting the pavement for long runs, increasing my mileage and building towards a goal. That goal? Running a marathon! During my training, as my weekly mileage increased, so did my carbohydrate intake.

Therein lies my exercise dilemma: carbs are both the key to having the energy to run AND the nemesis to fighting off fat storage.

Before I began training for my first marathon, eating during exercise had never crossed my mind. In fact, during and after workouts, food is the last thing on my mind. I remember orange slices during half time at youth soccer games, but I always thought that was just for extra hydration. The only thing palatable after a workout for me was watermelon or pineapple – or even better, a big glass of water.

But when my casual weekday runs transitioned into training for a marathon, new research and conversations with fellow runners brought the concept of fueling during a run to my attention. It seemed so odd. Here I thought I was simply building endurance to get myself to mile 8, 12, 16….26.2. Come to find out, there’s a whole science behind it. Here’s the breakdown…

Carbohydrates = Sugar

Sugar stored in the body = Glycogen

Glycogen = Energy

Our glycogen levels are what fuels us for our daily activities, especially high-intensity and aerobic training, like running. According to the National Institute for Sports Professionals, an athlete stores about 2 hours worth of glycogen to use for high-intensity training.

For me, this means I can run just under 14 miles on all the glycogen stores in my body. After that, I'm literally running on empty. I'm no 'Boston Qualifier' at this point, so that leaves me nearly 2 more hours of running that I'll have to fuel for while I run. But do I really want to let the tank hit empty before I start refueling? Most definitely not! Especially when precious seconds-per-mile mean the difference between making and missing the goal I've worked towards for months.

I've found that many long distance runners follow the 75 minutes rule. While your body has enough glycogen stores for 2 hours of running, you'll need to have something left in the tank when you hit that 2 hour mark so your system has time to absorb the fuel you provide.

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Many products (like energy gu's or gels) say to refuel every 45 minutes of exercise. Much like the chart on the back of your dog's food bag, this is excessive and will leave you with a fat dog and a light wallet. My ultimate goal in refueling is to stay in the positive, but not to carry more than I need. With my frame and pace, I find that 100 calories of carbohydrates (about 25 grams) is sufficient to fuel me for an additional 6 miles after the first 75 minutes. For a marathon, this means taking an Energy Gu at mile 8, mile 14 and mile 20. Any carbs consumed after mile 20 won't be absorbed in time to help me during the race (Vanilla Bean Gu and Strawberry Clif Shot Bloks are my fuel of choice. They work best with my taste buds and sensitive tummy).

With that said, it is a myth that carb loading before a big event is necessary to have the energy you need. Your body only stores so much glycogen, then turns the leftover supply to fat. Unless you just finished a long workout and haven’t eaten anything, you have all the glycogen you need stored in your muscles already.

I struggled to find the delicate balance between having enough carbs (glycogen stores) in my system to be prepared for a race and enough self-control to not load up on more than I needed. I’ve found that eating my normal high protein, low carb diet in the days before a race is sufficient to power me through that first 75 minutes of a challenging run. From there, I must replenish with simple carbs to finish the race feeling strong.

I’ve come to embrace running fuel as that ever-so-rare sweet treat that I need (and work hard for!). It may look like an indulgence, but it’s exactly what my body needs to finish the race strong. Training for my marathon helped me accomplish so many goals – looking and feeling the best that I can, pushing the boundaries of what my body can do, and above all, being the healthiest me that I can be. I was able to do all these things because I put aside the fear of carbs and listened to what my body needed to make my goals a reality.


Mary Doyle has a few confessions... she brushes her teeth in the shower just to get a few extra minutes of sleep in the morning, she would willingly run a marathon every weekend if you let her (what is she... crazy?) and she's a textbook Gemini - either meticulously counting calories OR shoveling down cupcakes like there's no tomorrow! Mary has a shameless love affair with the great outdoors... she loves hitting the pavement for a run, cruising up and down the beach on her bike or relaxing in the sand with a magazine. Oh... and don't cross her with your bag of potato chips. Mary's biggest pet peeve is (in her own words) "listening to someone eat potato chips. The 'chomp, chomp' is worse than nails on a chalkboard. I don't like the texture of potato chips or the way they stick in my teeth. When hearing this sound, I can feel the texture and grit, and I cringe with disgust and have to leave the room". So basically... don't invite Mary to your next BBQ, but if you're looking for a running buddy, she's definitely down! Oh... and Mary has her own blog called Running and Losing. Check it out and show her some love!

P.S. I am taking submissions for Operation Snail Mail through the end of the day today. Don't miss out on this amazing project! To learn more, click here!

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