Fueling Workouts: What and When to Eat Before Exercise for Optimal Performance

Strategies to Build and Maintain Energy Reserves

Bagel

Verywell / Alexandra Shytsman

The food you eat before, during, and after a workout can not only affect your performance but your comfort, as well. Eating the right energy foods at the right time—including energy bars, drinks, gels, and other easily digestible carbohydrates—can provide you with the energy resources you need without overtaxing your digestive system.

To perform at your peak, you should stage the foods you eat. That means focusing on quality carbs which your body can convert into glucose for immediate energy, the reserves of which are converted into glycogen for future use. After exercise, you need to replenish your glycogen stores to aid in recovery and be ready for your next workout.

Importance of Pre-Exercise Nutrition

Fueling your body adequately before exercise can help you feel and perform your best. It may help boost energy and endurance to power you through a workout. Research even suggests pre-exercise nutrition may enhance recovery and tissue repair and improve your mood after workouts.

Carbohydrates supply glucose to fuel your muscles, so eating a carb-rich snack prior to a workout can help improve your glycogen stores, or stored fuel, to keep you going.

For intense workouts lasting more than an hour, it can also be helpful to add a little protein along with the carbohydrate to enhance performance and minimize muscle soreness and damage.

It's also important to drink plenty of fluids before and during a workout, especially in hot and humid conditions when more fluid is lost in sweat.

Calculating Your Nutritional Needs

You need to structure your eating plan based on the intensity, duration, and type of workout you intend to do. This is especially important if you are competing in an all-day event, such as a marathon, track meets, or team sporting event. Some activities burn energy rapidly, while others require a slow and steady fuel supply to keeping you going for the long haul.

To this end, it is important to know how much energy you will likely expend during the activity:

  • If a workout is less than 45 minutes, you may only need a snack 30–60 minutes beforehand, water during the workout, and a snack afterward. A good post-workout snack will have a 3:1 carb to protein ratio (such as chocolate milk).
  • For endurance exercises of 1 to 2.5 hours, aim for 30 to 60 grams of carbohydrates per hour. This will provide ample carbs to supplement your muscle glycogen reserves during exercise.
  • For endurance exercises exceeding 2.5 hours, aim for 60 to 90 grams of carbohydrates per hour. If you experience stomach issues, then decrease the carbohydrates consumed per hour.

What to Eat Before Exercise

Eating before exercise is something only the athlete can determine based on experience, but, as a general guideline:

  • Eat a solid meal 4 hours before exercise.
  • Eat a snack or a high-carb energy drink 1 to 2 hours before exercise.
  • Consume a replacement drink 1 hour after exercise, preferably one with a 3:1 carbs to protein ratio.

Pre- and Post-Exercise Eating Strategy

To prepare for your workout, you need to replenish your glycogen stores upon waking since you will be in a fasted state. You should do so well enough in advance of the activity so that you don't work out on a full stomach. Depending on how much food you eat, allow yourself anywhere from one to four hours to properly digest the pre-exercise meal.

If you plan to workout intensely for more than an hour, a combination of carbohydrate and protein beforehand can be helpful. A meta-analysis showed that endurance athletes had slower time-to-exhaustion and faster time-trial performance when they ate a combination of carbohydrates and proteins before exercise compared to carbs only. The most common ratio of carbs to protein in the studies was 4:1.

If you have an early morning event, it is best to get up as early as possible to start your eating plan. If you are unable to do so, eat or drink an easily digestible carb source (like a banana) no more than 20 to 30 minutes before the event.

Clearly, the closer you are to the start of the event, the less you should eat. If you fail to fuel up at all, you risk compromising your performance, especially if you haven't conditioned yourself to exercise without a pre-snack or pre-meal.

Within 1-2 hours of completing a long or high-intensity workout, consume high-quality protein sources or, if time is short, a protein shake. Some studies have shown that consuming 25g of protein in this window is beneficial.

You will also need to consume 0.5 to 0.6g per kilogram of body weight of rapidly-absorbed carbohydrate (approximately 150 calories for a 160-pound athlete or the equivalent of one medium potato, one cup of pasta or white rice) every 30 minutes for the next 2 to 4 hours. This will replenish your glycogen stores as well as promote muscle protein synthesis.

Pre-Exercise Snack Options

Because glucose is the preferred energy source for most exercise, a pre-exercise meal should include foods that are high in carbs and easy to digest, such as pasta, fruit, bread, energy bars, and energy drinks.

The type of carb you choose also matters. If you're attending an endurance event, go with a carb with a low glycemic index (GI). Low-GI carbs don't raise the blood sugar quickly but rather maintain glucose levels at a steady state for a longer period of time. These include such foods as oatmeal and anything whole grain.

If your activity is short but intense, skip the whole grains and go instead for high-GI refined grains that raise the blood sugar quickly and give you a burst of energy off the starting blocks. Here are just some of the foods to consider prior to the start of an event.

3 to 4 Hours Before Exercise

Whole grain cereal
Verywell / Alexandra Shytsman
  • Bagels
  • Baked potato
  • Cereal with milk
  • Energy bar
  • Fresh fruit
  • Pasta with tomato sauce
  • Toast with peanut butter, lean meat, or cheese
  • Water
  • Yogurt

2 to 3 Hours Before Exercise

Bagel
Verywell / Alexandra Shytsman
  • Bread, bagels, or pasta
  • Fresh fruits
  • Oatmeal
  • Yogurt
  • Water

1 Hour or Less Before Exercise

Grapes
Verywell / Alexandra Shytsman
  • Energy gels
  • Fresh fruit, such as apples, peaches, bananas, or grapes
  • Up to 1 to 1/2 cups of a sports drink

What Not to Eat Before Exercise

Foods with a lot of fat or fiber can be difficult to digest and tend to remain in the stomach for a long time. What this means is the blood meant to deliver oxygen to the muscles will instead get diverted to the stomach. If this happens during exercise, you are likely to experience cramping, stomachache, and nausea. As a rule, avoid foods like doughnuts, fries, potato chips, candy bars, or red meat.

While beans, dried fruit, coleslaw, and dairy may fit the bill nutrition-wise, you may want to skip them and other potentially gassy foods prior to exercise if you are prone to bloating.

Before a workout, skip any foods that are difficult to digest (high fiber or high-fat foods) or low in nutrient value, such as fried foods and candy.

Avoiding Common Pitfalls

It's important to plan out the timing of your workouts and meals each day to avoid eating too much or too little beforehand and to pack snacks that will give you the fuel you need. Common pitfalls include:

  • Eating a heavy or fatty meal close to a workout
  • Relying on sugary snacks
  • Skipping pre-workout fuel

It can be helpful to establish a pre-exercise eating routine that you know works for you. It may take some experimentation to find which pre-exercise foods work best to sustain your workouts.

Although sugary food like candy cookies can give a short burst of energy, they don't offer nutrition your body needs. Choose snacks that fit into an overall healthy eating plan. For example, opt for fresh fruit and bread with nut butter instead. It can be helpful to keep some pre-exercise snacks with you so that if your schedule changes, you'll still have them available before a workout.

Even when you have a routine, plan to adjust it as needed. For example, if you know you will going out for a heavy lunch and usually workout in the middle of the day, try to plan your workout in the morning or wait at least four hours to allow some time for digestion.

Planning out your pre-exercise foods will help you feel energized not depleted and may help you reach your fitness goals.

5 Sources
Verywell Fit uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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  2. Kloby Nielsen LL, Tandrup Lambert MN, Jeppesen PB. The effect of ingesting carbohydrate and proteins on athletic performance: a systematic review and meta-analysis of randomized controlled trialsNutrients. 2020;12(5):1483. doi:10.3390/nu12051483

  3. Ormsbee MJ, Bach CW, Baur DA. Pre-exercise nutrition: the role of macronutrients, modified starches and supplements on metabolism and endurance performanceNutrients. 2014;6(5):1782–1808. Published 2014 Apr 29. doi:10.3390/nu6051782

  4. Yalçın T, Al A, Rakıcıoğlu N. The effects of meal glycemic load on blood glucose levels of adults with different body mass indexesIndian J Endocrinol Metab. 2017;21(1):71–75. doi:10.4103/2230-8210.195995

  5. Grundy MM, Edwards CH, Mackie AR, Gidley MJ, Butterworth PJ, Ellis PR. Re-evaluation of the mechanisms of dietary fibre and implications for macronutrient bioaccessibility, digestion and postprandial metabolismBr J Nutr. 2016;116(5):816–833. doi:10.1017/S0007114516002610

Additional Reading
  • Kanter, M. High-Quality Carbohydrates and Physical Performance: Expert Panel Report. Nutr Today. 2018;53(1):35-9. DOI: 10.1097/NT.0000000000000238.

By Elizabeth Quinn, MS
Elizabeth Quinn is an exercise physiologist, sports medicine writer, and fitness consultant for corporate wellness and rehabilitation clinics.