Exercising in the AM on an Empty Stomach

Yesterday morning I committed one of my cardinal sins – working out on a completely empty stomach! I knew this as I headed out the door for my interval run, but rationalized it by saying I had a late dinner + a snack afterward the night before. Still, that was more than 9 hours prior, which is technically a fasted state. Exercising when the body is in a fasted state is no bueno. Here’s why.


When you wake up in the morning feelin’ like P Diddy, the body is typically in a fasted state (providing you didn’t wake up at 4:00 a.m. for a snack.) Adding exercise to the equation stimulates the body’s inner furnace, and without eating a pre-workout snack, it won’t have any fuel to convert to energy.

Even if you wake up with no appetite, or your appetite disappears when you start working out, you still need to eat something. Without consuming something beforehand, the body has to turn to glucose and fatty acids from the blood and then breaks down muscle protein for energy to get through the workout. I know I don’t want to break down the muscle I worked so hard on building during the previous day’s strength workout!

Moreover, by tapping these energy stores, we’re more likely to feel famished and binge later on throughout the day.  And if saving calories is your concern, consider this: evidence supports that eating breakfast before working out actually leads to a higher calorie burn during your workout!

The International Journal of Sport and Nutrition Metabolism conducted a recent study that measured a group of men who performed a 35 minute treadmill workout both after eating breakfast and without eating breakfast. The group who ate breakfast beforehand showed a significantly higher calorie and fat burn post-workout than those who didn’t break the nighttime fast, due to an enhanced utilization of fat during the workout. Yikes! I don’t think I’ll neglect breakfast anytime soon Winking smile

Knowing this, the next logical question is probably, “what should I have for breakfast before working out??” Something is always better than nothing, so while not optimal, something as little as fruit juice or a donut is better than skipping altogether. However, good choices include a meal that has carbs and fiber, such as from a piece of fruit, as well as a low-fat protein source, such as yogurt or milk. That said, what works best for me is either a banana and a little bit of PB before cardio, and the same or a protein shake before lifting.


On that note…breakast!

I woke up at 5 this morning to train an early client, and because I needed something, I had half a banana with a tsp of sunflower butter. Now I’m eating some full fat Fage greek yogurt, blueberries, and a drizzle of honey. This has got to me one of my favorite breakfasts. simple and delicious Smile

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  1. This is such good information. Usually I force myself to eat something anyway because i’ll start feeling winded if I try to work out on an empty stomach, but it’s good to know that not only am I not pushing myself as hard as I could be, but I’m also not maximizing the workout benefits.

    Don’t you love that berries are in season? They’ve been so delicious and inexpensive!

  2. I actually don’t eat before working out if it’s a very, very early run/cardio session. I claim that I have an “iron stomach” but I get super nauseated if I eat in the wee hours of the am. I make sure to eat right away after, though!

  3. Great post! I never used to eat before I worked out in the mornings, especially it was running because it led to uncomfortable tummy issues but now I make sure to eat at least a banana before. It isn’t much but like you said better than nothing!

    My only thing is that when I sometimes work out before work (5:30am) I am basically rolling out of bed at 5:15am and going to the gym so that appetite hasn’t kicked it yet. But you are right I notice that I have way less energy and by the time I get home I am starving. Looks like I need to make a change here!

  4. I always work out on empty because I have a sensitive stomach/GI tract. I don’t know what the cause of this is… I just either get bowel-y or puke-y if I eat before a run… sometimes as much as hours before. Other cardio is less terrible, but in reality, any kind of bouncing just makes the workout uncomfortable after food. Walking and biking would probably be my only choices.

  5. Aside from the body breaking down muscle, I just feel lightheaded if I try to workout without eating something first! No bueno :)

  6. I always do cardio on an empty stomach! Weights are another story. Luckily I am too lazy to work out in the morning, so by the time my workout rolls around, I have already eaten 3 times. I just can’t eat less than an hour before cardio. Barf.

    Hope you have a great weekend!!!

  7. I always eat before working out! I just don’t understand how people can workout on empty stomachs. I did it once last year and I felt so weak and wanted to fall over… I sure learned my lesson!

  8. stephanie says:

    I’m super guilty of not eating before morning workouts…something I need to work on :)

  9. Eek, I always work out on an empty stomach in the mornings! I need to change this. Thanks for the info!

  10. Hate to say it, but I’ll run up to 12 miles on an empty stomach in the morning! I have such a sensitive stomach, that I have to wait at least an hour even for half a clif bar to digest. And I like to just wake up, roll out of bed and go.

    I know it’s not good….. but it works for me!

  11. My tummy always battles me when I try to eat anything too heavy prior to working out in the AM, but I always have a little something something. Love the info you put in this post (and really love that you put in “like p diddy” quote hahahah). mmm fage. mmmm with honey and fruit- so good!

  12. That research is so uplifting! I used to believe that not eating before a workout would burn more fat, but I had such weak workouts that I realized if I ate something (even just half my breakfast and half after) I would have a much more energetic workout…which benefits my body in so many ways.

    • I know – it’s crazy how much better I’ll do in one spin class to another…the only difference being I ate a little breakfast beforehand!

      • I totally agree with this, although for years I used to do my cardio and weights on an empty stomach a la Body For Life. Although I got ripped and fit fairly quickly (and looked great) I really struggled to get through my workouts each time. Now I do what Angela suggests and eat half my breakfast first and half afterwards. Thank you for such an informative post.

  13. Thanks for sharing some research behind this. I need food to function in the morning. Even if I wake up super early to workout, I’ll grab a banana and PB or a something to keep me going. So many people still say that it’s better to workout on an empty stomach and it drives me crazy!

    • That’s my go-to early workout snack too :)
      So many people say SO many things that are eye roll worthy, right? But then again research is always changing and evolving with fitness/nutrition, so you can’t really say anything with 100% certainty! lol

  14. ah great tips!

    bfast is definitely super important, but i always wondered if it was better to eat it before or after the workout. thank you for posting this :)


  1. […] had a good time reading everyone’s comments about eating breakfast before early morning exercise. A lot of you don’t, or even can’t eat breakfast before working out! Sometimes I feel this way […]

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