by Last updated on November 6, 2026 (originally published on April 19, 2017)
We all know that what you eat is important for good health, a strong immune system and energy for, and recovery from, exercise. But what about when you eat? Does the timing of your meals impact performance and recovery?
The long-standing advice in the world of sports nutrition is that what you eat and when you eat do, in fact, impact your training goals. Proper nutrition can:
- Improve performance
- Decrease injuries
- Enhance muscular power
- Increase reaction time
- Boost strength and endurance
- Improve recovery
The exact composition of your meals with regards to your macros (protein, carbohydrates and fat) varies from person to person, as you must take into consideration your goals, type of exercise (aerobic vs. strength), intensity of exercise, duration of exercise and how much time there is between exercise sessions. With all of these factors to consider, there is no one-size-fits-all answer.
Additionally, most nutrient-timing recommendations are based on studies that have been conducted on various types of athletes (professional-level) across multiple types of sports including, but not limited to, cycling, swimming, running and weight training. Therefore, for most clients, these recommendations should serve as more of a guideline rather than strict dogma.
What to Eat Before Exercising
The main purpose of eating before exercise is to provide your body with enough fuel to sustain your energy level throughout your workout so that you can achieve your workout goals. Carbohydrate-rich foods and fluids help “top off’ glycogen stores, while protein can help to preserve muscle mass. A meal that has a combination of these macros is ideal. High-fat meals are generally not recommended before a workout because fat slows digestion and may leave you feeling sluggish.
One of the most important tools in your pre-workout arsenal is hydration. When you do not consume enough liquid from water (or decaf/herbal tea, coffee, milk, juice—yes, these all count) or eat enough fruits and vegetables to stay hydrated, your muscles will fatigue much more quickly, your coordination will decrease, and you will be more likely to develop muscle cramps. Plus, your body will not be able to regulate its core temperature, and an increase in core body temperature can lead to overheating and exhaustion.
What Time Do You Exercise?
Next, consider at what point during the you exercise. Whether you work out first thing in the morning, mid-day or in the evening will factor into your meal-timing strategy.
If you work out first thing in the morning, you may not have much time to eat and allow your food to digest. Because liquid digests faster, a small smoothie might work well as a pre-workout meal. If your experience is that any type of food doesn’t sit well with you, it may be better to eat nothing.
Also, take into consideration the type and duration of exercise that will be performed. If you’re going to do an endurance workout (>60 minutes) or high-intensity interval-training workout, you are at greater risk of glycogen depletion, hypoglycemia and fatigue during exercise. Pre-workout meals are vital, and you might also consider consuming a drink with 30 to 60 grams of carbohydrates each hour during prolonged exercise.
If you work out later in the day, you can time your meals to help provide you with enough fuel to perform your best. The greater the amount of time between your meal and exercise, the bigger the meal can be. If you have one hour until your workout, a meal or snack containing 1 gram/kg of body weight of carbohydrate is appropriate. If you have two hours until your gym session, take in 2 grams/kg of carbohydrate. With three to four hours until your workout, consider a meal with 3 to 4 grams/kg of carbohydrate. Including 15 to 20 grams of protein in your pre-workout meal can help with blood-sugar control, maintain or increase muscle mass, and decrease muscle damage during the workout.
What to Eat After You Exercise
For a post-workout meal, aim for 15 to 25 grams of protein (for tissue repair) and 1 to 2 grams/kg (of body weight) of carbohydrates per hour of glycogen-depleting exercise. Add 5 to10 grams of fat for satiation purposes. You don’t need to worry about protein powder versus whole foods or type of carbohydrates (low-glycemic vs. high-glycemic). More than anything, a well-balanced meal containing a variety of real, whole foods and plenty of fluid is the best post-workout meal you can eat.
Should You Eat Before Bed?
This is another question that has the nutrition world completely polarized. There are those that believe that eating before bed will have your body digest and store the food as body fat and lead to weight gain. But if you exercise in the evening, the nutrients in a post-workout meal will go toward glycogen synthesis and muscle repair. Regardless of the time of day or night, you must nourish the body after exercise to switch from a state of catabolism to anabolism.
Hydrate Throughout the Day
Staying hydrated is an all-day affair. The goal is to drink just the right amount of fluid and/or electrolytes before, during and after exercise to maintain a state of euhydration, which is a state of “normal” body water content—the perfect balance between “too much” and “not enough” fluid intake. Consider the following guidelines:
Before Exercise
- Drink 5 to 7 mL/kg (0.08 to 0.11 oz/lb) at least four hours before exercise
During Exercise
- Monitor individual body-weight changes during exercise to estimate sweat loss.
- Composition of fluid should include 20 to 30 mEq/L of sodium, 2 to 5 mEq/L of potassium and 5 to 10% of carbohydrate.
- Prevent a >2% loss in body weight. Amount and rate of fluid replacement depend on individual sweating rate, environment and exercise duration.
After Exercise
- Consumption of normal meals and beverages will restore euhydration.
- If rapid recovery is needed, drink 1.5 L/kg (23 oz/lb) of body weight lost.
The Bottom Line
What and when you eat can make a big difference to your performance and recovery. Well-balanced meals and fluid are important for energy production, recovery, prevention of injuries and proper growth. Both meal composition and meal timing must be individualized for each person based on sex, age, body type, and type, intensity, duration and frequency of activity. Making sure to consume meals that are balanced in macronutrients and composed of real, whole foods is a great place to start.
Looking to expand your nutrition knowledge and learn how to translate that information into actionable lifestyle changes for clients and patients? Learn more with ACE’s Fitness Nutrition Specialist program.
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