Eating on the Run {Fitness Friday}

As an athlete and coach, one of the things I think is important is constant learning. With so many new concepts being shared, I’m admittedly critical when I hear new nutrition strategies. There are times when things make sense in theory, but in practice it doesn’t work for me. During my USA Triathlon certification last year, Bob Seebohar spoke on the concept of Metabolic Efficiency and it was one of those times where it did make sense, but I still had to try it for myself.

Today I’d like to share an overview of what I learned about Metabolic Efficiency and the changes I’ve made to my running (biking, and swimming) nutrition based on these concepts.

Metabolic Efficiency Sports Nutrition

Just a quick reminder that I am NOT a nutritionist – this is what I learned what works for me. It may or may not work for you. This is intended as my opinion based on my experience, so you can make your own decision.

The Basics

The basic concept behind metabolic efficiency is to control your blood sugar to burn more fat. High blood sugar equates to high insulin, which impedes your body’s ability to oxidize fat. So the goal is to have an even distribution of blood sugar throughout the day.

Each meal should be about half (or more) fruits & veggies, then lean protein and healthy fats, finally a little whole grains. The grains should be the smallest portion on the plate, especially during the off season. Bob goes into much more detail in his book, which I recommend for more information.


You’re basically teaching your body to use more fat by controlling blood sugar, which has the added benefit of reducing body fat. This isn’t something you do just while training, it’s a way to change your daily diet (nutrition) to improve your body’s metabolic efficiency.

As you improve your metabolic efficiency, you should be able to reduce the amount of calories you need during training.

Why Metabolic Efficiency?

I think Bob says it best:

[Better metabolic efficiency] has allowed hundreds of athletes to fuel with fewer calories during training and racing, which decreases reliance on simple sugars. (source)

Fewer calories during training and racing means less chance for Gastrointestinal (GI) Distress. I find that eating a mostly plant-based diet also helps significantly for me, but everything I can do to further reduce the chances of this issue, the better!

What Does This Look Like?

You may remember I originally shared my thoughts on running fuel in a series early last year (part 1, part 2, part 3). Instead of revisiting all the details in there, I thought I’d focus on how my strategies have changed for me:


As long as I’m eating consistently throughout the day (Every 3-4 hours ideally for best control of blood sugar), I don’t usually eat a snack before a training session. In fact, I’m completing most morning workouts on an empty stomach without a problem! I’m better able to tap into my stored fuel without sacrificing performance.

The one thing I am careful about here is sugar intake – I don’t want a spike in blood sugar just before I begin my workout.

During Workout

I eat a lot less calories during training and racing than I used to. In the past, I started adding nutrition for typical workouts of 90 minutes or longer, with 100 calories every 40-45 minutes. When I did my first Ironman, I believe it was more like to 200-250 calories per hour.

Today, I save sports nutrition for workouts of 120 minutes or longer, with just 100 calories per hour. For runs, I eat a Vega Gel with water every hour. For bikes, I eat 1/2 a Vega Endurance Bar with water every hour. Swimming is always just water.

Vega Sport Endurance Bar

That means for a 2 hour workout, I take in 200 calories, instead of 300+ calories. That really adds up for the longer races like marathon, half ironman, and ironman distances.

Post Workout

This hasn’t really changed, other than being aware that a hard workout doesn’t mean I get to eat whatever I want. :)

So What?

This is a lot of information, so what should you do with it? Think about what you’re eating and adjust the proportions and frequency. Review what you’re eating before, during, and after your workouts – do you need nutrition on all  your workouts? How much?

If you interested in nutrition and getting deeper into these concepts, consider getting a copy of Metabolic Efficiency and learn from Bob directly. I’ve also just downloaded Nutrition Periodization for Athletes: Taking Traditional Sports Nutrition to the Next Level, which I’m excited to read and expand my knowledge in this area.


DISCLAIMER: I was not compensated for this post in any way, in fact I doubt Bob remembers me from USAT training last year. Some of the links in this post are affiliate links I set up for products I love, I make a small commission from each purchase made through those links.

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  1. says

    I geek out on food theory. Now days Ineed to eat something small, but when I was running short distances (5-8 miles) in the morning I wouldn’t eat anything. But I definitely agree there’s no need for a suagr rush before a workout! Very interesting food for thought. 😉
    Laura @ Sprint 2 the Table recently posted…Strange But Good TravelsMy Profile

  2. says

    This is a really great, informative post. I am so happy to read about someone who is eating a well rounded diet and thriving on it (not cutting out food groups as is so trendy right now).

    I also have changed in the past year in terms of what/how I eat before and during workouts. I used to always fuel before any workout. Now, not very often (20-milers and hard speedwork the exception). I have also cut back on calorie intake during workouts.

    Thanks for sharing this!
    misszippy recently posted…Into the woodsMy Profile

    • says

      You’re right – how did that become so trendy? I would definately be fueling up before a morning 20 miler, but it’s interesting how your body adapts and anything I can do to reduce the dreaded GI distress is excellent. Glad you enjoyed the post!

  3. says

    Very interesting! I pretty much always eat before going for a morning run but I’m actually really hungry in the mornings because I have light dinners. I don’t consume much calories doing my long runs though, maybe 150ish (1/4 cup of raisins or some homemade gatorade) for a 10 mile run.

    I remember Rich Roll talking about with time he doesn’t need to each as much as he trains. Out of curiosity, what happens to your metabolism after you stop training? Will it permanently get “slower”. My grandma always warn me that when I stop exercising I’m going to get fat because all athletes do. Not sure if it’s another one of those “shit my grandma says” things (sry if that sounds rude but she does say a lot of bs) or actually true….
    Nadiya @ Milk and Honey on the Run recently posted…Everything happens for a reasonMy Profile

    • says

      I always used to be hungry before morning runs, it was a natural progression to where I am now. But if you’re hungry – eat!

      For 10 mile runs, I’m not taking anything now – it’s only when I get over the 12 mile mark. Crazy, right?! I think this is good for your overall metabolism, so I can’t imagine a negative impact when you stop exercising (but I’m no expert!). I think most people get fat when they stop exercising because they keep eating the way they always have. I know that’s something I have to be careful of even in normal training cycle changes.

      • says

        I think for me it’s more that I eat light dinners so I end up hungry in the morning 😛 I have successfully done 8k runs after 1 tbsp of pb or a granola bar… I remember doing a project on this for my metabolism course and apparently elite marathon runners don’t eat during the marathon. They are just able to burn much more fat in relation to carbs that they don’t really “bonk”. I need to work on building up my aerobic respiration 😛

        I think that’s the case when athletes stop exercising too. 😛
        Nadiya @ Milk and Honey on the Run recently posted…Trying new thingsMy Profile

  4. says

    i bet Bob remembers you! how could he forget?! great post friend. James is very similar but then again, he has found what works for him. That’s key!

    • says

      Ha! I’m probably remembered as the girl who jumped in to defend veggie diets against a crazy guy in our class. I hope to meet him again one day and let him know how much I enjoyed his session – it was the highlight of the training for me!

  5. Nicole @ Fruit 'N' Fitness says

    What an interesting post! I have recently started training for my first half marathon and have been struggling with what to eat, when, and how much. I get really dizzy if I dont eat before a run (mind you a long run for me is currently 8 miles). there have been many foods that have caused some horrible stomach/gi issues while running. I will have to look into Bob’s book to read more helpful tips.

    • says

      I’m not an expert, but maybe look at how you’re eating on the days you run (in general). I have to eat something if it’s been too long since my last meal, but it’s all about timing and where your run fits into that cycle. I know there are some snack recommendations in the book – the big warning is not to eat a gel before your run, because you don’t need that sugar spike.

    • Doug says

      It might help to look at your total calories for the day and hydration.

      Like Heather, I’m not a nutritionist, but you have plenty of glycogen in your muscles to run 8 miles.

  6. says

    Very cool. Thank so much for sharing this. I don’t typically workout longer than 90 mins maybe shy of 120 when doing 12-13 mile runs. I have found that I really only end up needing a gel (100 cals) when I’m hitting the 10 mile mark. I try to take that around 6-7 miles into a run to get me through the last bit. I didn’t do that the other day and started to really die by the last mile. I know some people take more, others less. I also think it’s key to listen to your body. I always have a hard time post-run b/c I absolutely don’t want anything. And I actually do far better than I thought I ever would not eating before a morning run and if I do have a pre-workout snack, it’s very little, just to keep my tummy from growling LOL
    Heather (Where’s the Beach) recently posted…Thoughts & Things: Blood Thinners, Running, Bike TrainerMy Profile

    • says

      You’re absolutely right – listen to your body! I think the key takeaway is training your body to avoid the blood sugar changes and fueling properly regularly and it will naturally adjust to need less (because it can better access stored fuel) at the “shorter” distances. I always used to need a gel at around 9 miles too. And like you – I need an hour after a long workout before I want food usually.

  7. says

    This is interesting. This is basically how I try to eat, since grains bug my stomach anyway, but I’m curious as to how to fuel during long runs (1.5 hours or more). I was hoping there’d be tips in this post! :) Something not super sugary. I know your brain needs glucose at that point, but I’m not a huge fan of the clif blocks and stuff like that. I’d rather find something with less sugar.

    You know, when I start running again. I’ve got 8 more months. 😉
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  8. says

    I have been very curious about sports nutrition since I started running, however I generally have carbs and protein before a longer run, nothing special before a short workout, and try not to alter my eating habits too extremely. [Although I do get an occasional CRAZY carb craving or something following a long run.] I do not eat during runs, but I’m doing OK without that, so I guess I don’t need to? I’m still a little confused about that, to be honest.
    Sarah @ The Smart Kitchen recently posted…Mango Peach + Olive SalsaMy Profile

    • says

      What I’ve learned is if you’re fueling your body properly, not letting your blood sugar fluctuate, you shouldn’t need anything but water for workouts under 2 hours (and he says maybe up to 3 hours). Your body has the ability to access stored energy during that time. So yes, it sounds like you’re already naturally doing that. :)

  9. says

    My biggest challenge is eating conscientiously after a workout. I’ve definitely “crashed” after a long workout because I got busy doing something else, and that’s a terrible experience that I don’t want to repeat!

    • says

      Maybe you could prepare your post-workout fuel before you start, that way it’s less thought after. I’ve brought things with me in the past when I couldn’t get home immediately after and it works well for me!

  10. says

    I’m constantly trying to figure out what works for me. I’m finding that I don’t need much before a long run (which is less than 12 miles right now but will be ramping up soon) or even during the run. My tummy feels better for sure. For awhile I was trying to take in a gel just because everything I read said I needed too. Now I’m just listening to my body and it’s working a lot better.
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    • says

      I’m like you and tried so many things to make my tummy happy – eating less (or nothing) is actually something I never considered. You read so much that encourages frequent nutrition, like you said!

  11. says

    This is a really great post Heather. So much good information here. I’ve been curious to learn more about sports nutrition because basically I don’t really pay attention to it largely because I haven’t been “training” for a while. But it is definitely something that I want to pay more attention to. Thanks for this post.
    Christine @ Love, Life, Surf recently posted…Friday Round-Up: StrongMy Profile


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