Eating a snack before working out can drastically changed the results of your workouts: both cardio and strength sessions. Sure, athletic performance is still possible and you can still improve with regular practice on an empty stomach, but those improvements can’t bat an eye to their nutritionally-fueled counterparts. Let’s uncover why.
Why eat before exercising? Two main reasons are
1) that it can replenish your glycogen stores, meaning it can supply your body (your muscles, liver, and blood, in particular) with carbohydrates for energy and mental focus, enabling you to work harder, longer and more safely, and
2) to have amino acids readily available for rebuilding the muscles you’re tearing, creating a faster recovery!
For those who perform a resistance training workout, it’s important to note that consuming carbohydrates in particular beforehand also spares and replenishes glycogen in type 2 (fast twitch) muscles fibers which are used during this type of workout - think: enhanced speed for high-intensity stop-and-go sport activities. 4 Taking advantage of these fuel sources during the time when they are needed most is so beneficial for anyone wanting to see improvements in his/her fitness and overall health.
The optimal nutritional balance: The type and quantity of macronutrients is important to consider when choosing your snack. There are three macronutrients: carbohydrates, protein and fats. The two to focus on for your pre-workout snack are carbohydrates and protein. Minimal fat should be included in order to minimize any bloating or sluggish feelings during your workout.1,2
The half-empty bag of potato chips, doughnut and leftover mac-n-cheese just aren’t going to cut it though. Instead, opt for something lighter. If you like numbers like me, consider a snack that fits this:
5-20 grams (g) protein
15-30 g simple carbohydrates (such as fruit, white bread, or foods with little fiber)
and ≤10 g fat.
Some people look at macros as more of a ratios: 1 part protein to 3 parts simple carbs, if that’s easier to remember. Check out my printable snack list below to give you some ideas. And remember, how much you should eat will depend not only on how much you need, but on how much you can tolerate too.
How soon before your workout should you fuel? While I strongly encourage everyone to consume something before hitting the floor, how soon before a workout is also going to vary from person to person. Ideally, a snack would be eaten about 30-60 minutes prior to exercise. 3,4 Just enough time to get that sugar to your brain and amino acids ready for rebuilding. But like I said, exactly when can vary and depends on your tolerance. This is trial and error. If you feel too full or bloated during your workout when you eat 15 minutes beforehand, take it back a notch. I have found that I can typically handle a lighter snack, like a piece of fruit and a little peanut butter just 15 minutes before, and something a little more filling, like oatmeal more like an hour before. Try eating different lengths of time before your workout and pay attention to how you feel to find a timing (and quantity) that feels right for you.
Is there a case or place for exercising on an empty stomach? Short answer: yes. Fasted cardio is one type of workout that actually necessitates not eating beforehand. I'll cover more on this in a future post, but it's important to note that fasted cardio, when not done correctly, can actually inhibit muscle growth and, thus, your progress. I typically do not recommend doing fasted cardio more than 1-3 days per week.
Lastly, before we jump into some pre-workout snack examples, I want to recap that eating a snack about 30-60 minutes before a workout should supply your body with the needed energy and nutrients for pushing to new personal records and improved recovery periods. Learn your body, what it needs and what it can handle. Make it a habit and keep a snack in your gym back. You’re on your way to bigger and better things!
1. American Dietetic Association (2009). Nutrition and athletic performance. Medicine & Science in Sports & Exercise, 41, 3, 709-731
2. Jäger, R. et al. (2017). International Society of Sports Nutrition Position Stand: Protein and exercise. Journal of the International Society of Sports Nutrition,14(1). doi:10.1186/s12970-017-0177-8
3. Kreider, R. et al. (2010). ISSN Exercise & Sport Nutrition Review: Research & Recommendations. Journal of the International Society of Sports Nutrition, 7(7), 1. doi:10.1186/1550-2783-1-1-1
4. Reznik Dolins, K. & Coleman, E.(2017). Diet, Exercise, and Fitness: The Essentials of Sports Nutrition. OnCourse Learning Corporation.