“Imagine powering through your workout with unyielding energy, enhanced focus, & the stamina to push through even the toughest intervals—sounds like a dream, right? As a Registered Sports Dietitian & Coach, I can’t count the number of times I’ve seen people skip their pre-workout fuel only to hit a wall midway through their session. Trust me, the power of pre-workout fuel isn’t just for elite athletes; it’s a game-changer for anyone looking to maximize their performance & training results.
How Your Body Responds to Pre-Workout Fuel
Let’s first take a quick look at how carbohydrates signal multiple body systems in preparation for a workout. When you eat carbohydrates before exercise, your metabolism shifts to optimize energy production:
- Increased Blood Glucose Availability: Carbohydrates are quickly digested & absorbed, raising blood sugar levels & ensuring a steady fuel supply for your muscles. This sets the stage for your body to be ready for work!
- Reduced Reliance on Muscle Glycogen: Your body spares stored glycogen, which helps sustain energy levels during longer or more intense workouts. If you’ve practiced sound nutrition in the day(s) leading up to the session, your body will have plenty of stored glycogen for the long haul. But remember that your body relies heavily on that initial blood glucose to get the engine started.
- Improved Central Nervous System Activation: The brain relies on glucose for fuel, so giving your body a shot of carbs essentially lights up the brain so it’s ready for action. Even a small carbohydrate intake can improve focus, reaction time, & perceived effort.
How This Translates to Performance
With energy readily available, athletes experience:
✔ Higher Power Output & Endurance – Sustained energy means stronger efforts for longer.
✔ Faster Reaction Time & Decision-Making – Essential for sports requiring quick responses. (Like an open water swim with a few hundred friends!)
✔ Lower Perceived Effort – Workouts feel easier when the body isn’t struggling to access fuel.
✔ Enhanced Training Quality: Training at a higher level for longer improves the overall adaptations you’re seeking to get from your program
Power Up Your Pre-Workout Snacking
There’s no perfect timing for a pre-workout snack. It depends on how long your workout is, when you had your most recent meal, & what you can tolerate during the session.
A Good Rule of Thumb:
1 gram of carbohydrate for every kilogram of body weight per hour before the session
For example, a 70kg athlete would aim for 140g carbohydrate 2 hours before a session (70kg x 2hrs = 140g). (To calculate your body weight in kg: Body Weight / 2.246. Ex: 150lb / 2.246 = 67kg)
An easier session (skills-based or low exertion) usually allows for more flexibility with food choice. A more intense workout might require a simple, easily digestible option. And don’t forget that fueling for your morning workout starts well before that pre-dawn alarm sings. Think about how you can set yourself up to be nutritionally ready with nothing more than just a little top-off needed in the morning.
Pre-Workout Snack Ideas
The best pre-workout snacks are usually lighter in fat/fiber, carb-based & typically ingested 30-90 minutes before a workout. Here are a few options:
30-60 minutes pre-workout: 100-150 Calories
✔ Small banana
✔ 1 slice of toast with honey or jam
✔ Serving of crackers or pretzels (Goldfish, saltines, graham crackers, etc.)
✔ ½ cup applesauce
60-90 minutes pre-workout: 200-300 Calories:
✔ Large banana with a little yogurt
✔ 1 packet of flavored instant oatmeal
✔ A small bagel with jam
✔ 1 granola bar and a small handful of dried fruit
Fueling up before your workout isn’t just about the science—it’s about transforming your training sessions into opportunities to bring out your best. Imagine hitting the pavement with a burst of energy, feeling mentally focused & fully prepared for the work ahead. Even if you don’t feel hungry, a small snack can make all the difference. Experiment with different options to find what works for you & enjoy the ride!
References
- Hargreaves, M., Hawley, J. A., & Jeukendrup, A. (2004). Pre-exercise carbohydrate and fat ingestion: Effects on metabolism and performance. Journal of Sports Sciences, 22(1), 31-38.
- Jeukendrup, A. E. (2014). A step towards personalized sports nutrition: Carbohydrate intake during exercise. Sports Medicine, 44(S1), 25-33.
- Benton, D., & Owens, D. S. (1993). Blood glucose and human memory. Psychopharmacology, 113(1), 83-88.
- Aandahl, M.H. et al. (2021) ‘Effect of carbohydrate content in a pre-event meal on endurance performance-determining factors: A randomized controlled crossover-trial’, Frontiers in Sports and Active Living, 3. doi:10.3389/fspor.2021.664270.
- Wallis, G. and Podlogar, T. (2022) Gatorade Sports Science Institute. Available at: https://www.gssiweb.org/docs/default-source/sse-docs/sse_231_005.pdf (Accessed: 18 March 2025).
- Zdzieblik, D. et al. (2024) ‘Effect of a high carbohydrate pre-exercise meal on metabolic and performance-related parameters in male athletes following two different strategies to improve Fat Utilization: An exploratory examination’, Advanced Exercise and Health Science, 1(2), pp. 129–137. doi:10.1016/j.aehs.2024.05.004.”
If you’d like to chat with Erin about all things food & eating, feel free to email or connect with her through the Let’s Chat button on her website.
Here is a list of past articles written by Erin Green: