Should You Eat Before or After a Workout?
A registered dietitian nutritionist shares her perspective
Medically reviewed by Elizabeth Barnes, RDN
When it comes to improving or maintaining physical fitness, your exercise routine is crucial to your progress. But did you know that nutrition is just as important?
How you fuel your body before and after a workout may differ between a personal record or a sports injury.
Research shows that nutrition significantly affects exercise performance, muscle recovery, and overall health. It's also clear that there is more than one way to optimize your pre-workout and post-workout nutrition.
No matter your fueling plan, all three macronutrients (carbohydrates, fat, and protein) must be included. Along with water and certain micronutrients, all macronutrients are necessary for performance and recovery.
This article covers pre- and post-workout nutrition strategies and includes information regarding hydration, timing, macronutrient ratios, food choices, and supplements.
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A young black woman making a protein shake after exercise at home.Pre-Workout Nutrition Strategies
Your body requires the proper nutrients to generate energy. Therefore, eating before a training session may give you the fuel you need to perform at your best.
It's important to note that some research on pre-workout nutrition has been conflicting, possibly because what works for some people doesn't work for others.
Trial and error is an often recommended tactic for figuring out the best pre-workout nutrition strategies for you. Just be sure to avoid new routines on important training days, like game days.
Macronutrient Ratios
There are three macronutrients: carbohydrates, protein, and fat. And the ratio of these macronutrients you eat before a workout is an important consideration for your energy levels and lean muscle mass recovery.
There isn't strong evidence that one ratio is better than others. However, a standard recommendation is a 3-to-1 ratio of carbohydrates to protein before a workout. That equates to a snack with about 15 grams of carbohydrates and 5 grams of protein. The following foods have this ratio:
An apple plus a tablespoon of nut butter (almond, peanut)
An apple plus a tablespoon and a half of sunflower butter
One small Greek yogurt
A slice of whole-grain bread with one tablespoon of hummus
Carbohydrates
It's well-established that carbohydrates are your body's number one energy source. Carbohydrates (or glucose) used as fuel may come directly from a pre-workout meal, snack, or glycogen, a form of glucose stored in your liver and muscles.
While protein and fat also play an essential role in energy production during certain types of exercise, carbohydrates remain the go-to energy source.
Research shows that performance may improve following pre-exercise carbohydrate consumption. However, this effect may only apply to longer bouts of exercise. This means the need for pre-workout carbohydrates may increase as your exercise duration increases.
However, carbohydrates must also be available for resistance training and high-intensity interval training (HIIT). These tend to be high in intensity but short in duration compared to endurance workouts. Typically, short-term exercise is believed to be fueled by blood glucose, glycogen, and fat stores.
Meal and Snack Timing
Meal or snack timing is another crucial factor to consider for pre-workout nutrition. However, there isn't a clear consensus on the best time to eat before a workout.
Most research suggests that eating between one and four hours before a workout may be optimal. Eating too soon before exercise may increase the risk of mid-workout digestive troubles. Alternatively, eating too far out from exercise could leave you feeling easily fatigued.
What Does Fasting Before a Workout Do?
Some people exercise fasted, or when they haven't eaten for a long time, as might be the case for those who exercise right after waking up in the morning.
Fasting is believed to change the macronutrients and energy stores your body uses during exercise. It may also lead to certain adaptations that could alter your fitness.
There may be both advantages and disadvantages to fasting before a workout.
How Fasting Changes What Fuel Your Body Uses
When you exercise after fasting, there isn't a readily available glucose source as when you eat before a workout. However, your body can adapt and find a different source of fuel.
According to research, your body increases lipolysis, or the breakdown of stored fat, when you exercise after fasting.
Like glucose, your body can readily make ATP (adenosine triphosphate) from fat. However, while your body can generate more ATP from fat, the process takes longer than glucose.
For some people, exercising in a fasted state may help reduce body weight due to the increased use of fat stores. However, there isn't strong evidence that fasting before working out will enhance fat-burning for everyone or all types of exercise.
Overall, whether you fast before a workout may come down to factors like when you workout (for example, first thing in the morning versus evening), the type of exercise you do, and food availability.
Pre-Workout Nutrition: Impact on Short vs. Long Workouts
Fasting before a long or intense workout may do more harm than good, at least according to some studies.
Initially, during a workout, your body may use glycogen stores for energy. However, only so much glycogen can be stored. Glycogen stores may deplete after about 90 minutes of exercise.
If you've fasted before a workout lasting longer than 90 minutes, your body must use other sources besides glycogen or blood sugar to produce energy.
When fat (or, in some cases, amino acids) is used instead of glucose or glycogen, the process of making ATP takes more time. This can leave you feeling fatigued in some cases.
Some research suggests fasting may only be appropriate for low-intensity or short-duration workouts. Fasting before a high-intensity or long-duration workout may inhibit proper recovery and lead to poor performance.
Advantages vs. Disadvantages of Pre-Workout Fasting
For some people, scheduling conflicts and other factors may leave no other option besides fasting before a workout. However, there are both advantages and disadvantages to consider regarding pre-workout fasting.
Possible advantages of pre-workout fasting include the following:
You may burn more fat.
You may lose weight.
Acute and intermittent fasting may lead to specific metabolic adaptations, including possible improvements in blood lipids (e.g., lower cholesterol).
Possible disadvantages of pre-workout fasting include the following:
You may experience fatigue.
There are few reports of improved performance as a result of pre-workout fasting.
Some studies show decreased muscle and endurance performance in those who fast.
It may be more challenging to recover after training properly.
If I Fast Before Working Out, Should I Afterward?
While some proponents of fasting (especially intermittent fasting) say there are pros to fasting before and after a workout, science proves otherwise.
As previously mentioned, pre-workout fasting may be OK for some people, but it is also OK before certain types of exercise (like short-duration or low-intensity exercises). However, it's vital to replenish diminished nutrient stores after a workout, whether you fasted before or not.
When exercising in a fasted state, your body will most likely use glycogen and fat stores for energy. After the workout, glycogen must be depleted, and muscles must start to repair.
This is why it's recommended that you eat carbohydrates and protein after a workout, even if you didn't fast beforehand. Failing to eat after a challenging workout may result in decreased muscle and performance gains.
Pre-Workout Food Choices
With so many food options out there, it can be challenging to know what to eat before a workout.
When it comes to pre-workout food choices, some options may be better than others.
A combination of carbohydrates and protein is recommended before workouts. While carbohydrates will provide most of the fuel for your workout, protein will help jumpstart muscle repair afterward. Small to moderate servings of fat may also be included.
These recommendations apply to any active person, male or female, of any age.
Micronutrients (vitamins and minerals), which are also imperative to energy production and muscle recovery, should be included in pre-workout meals and snacks.
Research shows that all micronutrients are important to health and performance and that it's not necessary to emphasize some more than others.
Micronutrients are found in a variety of foods, both plant-based and animal-based, with whole foods containing more vitamins and minerals than ultra-processed foods.
With this information in mind, some ideas for pre-workout meals or snacks with an ideal ratio of carbs to protein include:
Fruit and nut butter
Greek yogurt topped with fruit or granola
Oatmeal with fruit and nuts
Toast topped with a hard-boiled egg or lean meat
Peanut butter toast
Pita and hummus
Fruit smoothie with s a protein source (nut butter, yogurt, milk, pea or whey protein powder, etc.)
Dried fruit and nuts
Remember, testing foods and meal timing before training is important to see what works best for you. Your pre-workout meal or snack should be easy on your stomach, so watch out for high-fiber or high-fat foods.
Hydration Before Exercise
Hydration should not be forgotten before exercise.
Drinking plenty of water before working out is thought to enhance your workout, reduce the risk of injuries, help your recovery, and prevent dehydration.
According to researchers, a lack of proper hydration may put extra stress on your heart and reduce your overall physical capacity.
To maintain adequate hydration, it's recommended that you drink water and other hydrating fluids before, during, and after working out.
Remember, too, that regular exercise may increase your hydration needs. As you exercise, you sweat to help regulate your body temperature. Sweating leads to fluid loss that must be replenished.
For proper hydration, it's recommended that athletes:
Drink 16–20 ounces of water or a sports drink two to three hours before exercise.
Drink an additional 7–10 ounces of water or a sports drink 10 to 20 minutes before exercise.
Replace fluids as needed during exercise; drinking 7–10 ounces of fluid every 10 to 20 minutes is generally recommended.
Hydrate post-exercise to correct any fluid loss (you can use urine color to indicate hydration).
Post-Workout Nutrition Principles
When you exercise, muscles and tissues become damaged, and your energy stores are depleted. This is where post-workout nutrition comes in.
Research shows that eating after exercise enhances muscle recovery, repair, and rebuilding. Post-exercise nutrition also helps restore glycogen stores.
Skipping meals or snacks after exercise may leave you feeling fatigued and irritated. Your muscles could also break down rather than rebuild.
Some researchers believe there is an "anabolic window of opportunity" in which protein should be consumed after a workout to prevent muscle breakdown.
An exact window has yet to be established, though. Some research suggests that the window is as short as 45 minutes to one hour post-exercise. However, other studies show that eating within five to six hours after a workout may still be beneficial, especially if food was eaten pre-exercise.
Remember that post-exercise nutrition goes well beyond just one meal or snack. Regular consumption of carbohydrates, lean protein, healthy fats, and micronutrients is important throughout recovery to prepare for the next workout.
Post-Workout Macronutrient Ratios
Similar to pre-workout nutrition, carbohydrates and protein remain essential in the post-workout period.
Carbohydrates are essential for restoring glycogen, while protein is the macronutrient needed for muscle repair and rebuilding.
For glycogen restoration and muscle repair, the International Society of Sports Nutrition recommends a ratio of 3-to-1 to 4-to-1 (carbohydrates-to-protein) after exercise.
These ratios may be adjusted depending on exercise intensity, duration, and goals. You would need even higher ratios of carbohydrates and protein after running a marathon compared to a regular workout. You may also eat more protein if you're hoping to build muscle.
More research is needed regarding the optimal timing of macronutrient intake after exercise. Various studies have demonstrated the benefits of eating carbohydrates and protein immediately, one hour, two hours, and three hours after exercise.
While fat stores aren't depleted during exercise, adding some healthy fats to your post-workout meal or snack may aid in your overall recovery process.
Optimal Post-Workout Foods
So, you've been told to eat protein and carbohydrates after a workout. But what exactly does that look like?
When choosing food sources of carbohydrates and protein, it's important to reach for whole or minimally processed foods as much as possible.
Research shows that a food-first approach is recommended for post-workout nutrition. Additionally, whole-food protein sources are recommended for their increased levels of amino acids and micronutrients needed for muscle repair and recovery.
Examples of whole-food, high-quality protein sources include lean meats, nuts and nut butter, eggs, legumes, and dairy products.
Some ideas for post-workout meals and snacks that include carbohydrates and protein (and fat) include:
Oatmeal with peanut butter and fruit
A piece of toast topped with cheese, lean meat, hard-boiled egg, or tuna salad
Scrambled eggs with roasted vegetables
Greek yogurt with fruit and granola
Cereal with milk (option to add protein powder and/or fruit)
Protein shake
Sweet potato and baked chicken
Hummus and crackers or toast
English muffin or bagel with nut butter
Brown rice and baked salmon or chicken
Does Macronutrient Timing Matter for Workouts?
There is often confusion surrounding the optimal timing of post-exercise meals and snacks. Unfortunately, research doesn't have a clear answer either.
Nutrient timing recommendations can range from immediately after a workout to several hours later.
While some research shows that muscles may be most sensitive to protein ingestion right after a workout, other studies have found that eating protein several hours after exercise can also be beneficial.
Other factors may also need to be considered, including if and when you ate before exercise. For example, if you fast before working out, you may need to eat as soon as possible post-exercise to aid recovery and avoid intense hunger pangs.
The time when you eat your post-workout meal or snack may depend on other factors as well. Many people have small windows to exercise before they return to work, take care of their children, or prioritize other obligations before food can be consumed.
The bottom line is it's important to eat after a workout, especially if it is long or intense. However, the window to consume carbohydrates and protein post-exercise appears to be large enough to fit most people's needs.
Using Supplements
Explainer
In the United States, the Food and Drug Administration (FDA) does not regulate supplements the way it regulates prescription drugs. That means some supplement products may not contain what the label says.
When choosing a supplement, look for third-party tested products and consult a healthcare provider, registered dietitian nutritionist (RD or RDN), or pharmacist.
Certain dietary supplements may complement your pre- and post-exercise nutrition.
Supplements may help fill in nutrient gaps that may be caused by certain diets (such as the vegan diet) or medical conditions. However, a food-first approach is recommended when possible.
Common ingredients found in supplements for athletic performance include the following, used alone or in combination with each other and other ingredients:
Vitamins
Minerals
Protein
Performance supplements are often not tested in humans before they hit the market. Or, if these supplements are tested in humans, the trials are often small and short-term. Therefore, their effectiveness should be questioned.
Thousands of dietary supplements promise to enhance workouts. However, the research supporting their use is limited overall.
Evidence shows that certain supplements may benefit physical performance when used alongside a well-balanced diet and proper training program. These include:
These and other supplements may improve endurance, aid recovery, extend the time to exhaustion, and increase strength. However, there is no guarantee that supplements for performance will work for everyone.
If you decide to try supplements, be sure to talk with a healthcare provider regarding safety and dosage. It's also essential to look for reputable supplement brands that have been third-party tested whenever possible.
Explainer
The following supplement categories had a three-fold increase in the risk for severe medical events compared to vitamins:
Muscle building
Energy
Weight loss
The use of these types of supplements is not advisable.
Special Considerations and Risks
Explainer
Supplement use should be individualized and vetted by a healthcare professional, such as an RD or RD or RDN, a pharmacist, or a healthcare provider. No supplement is intended to treat, cure, or prevent disease.
For some people, there are extra factors to consider when it comes to eating pre- and post-exercise nutrition.
People with certain medical conditions or at certain life stages (like pregnancy) will have additional concerns regarding what and when they eat surrounding their workouts.
For example, people with diabetes should check their blood sugar before and after exercise. It may also be necessary to check blood sugar during exercise to see if a mid-workout snack is needed. Blood sugar readings will determine whether it’s safe to work out and the amount of carbohydrates you should consume.
If you have kidney disease, work with a healthcare provider to determine proper protein goals during pre- and post-workout meals. While increased protein intake may be safe, some people with kidney disease need to eat smaller amounts of protein and other important nutrients for exercise.
Increased calorie intake is typically recommended during pregnancy. While exercise is also recommended during this precious time, pregnant people may need to eat more before and/or after a workout.
Regardless of your health status, hydration is always important when working out. However, some people require more fluids than others and should know the signs of dehydration.
Checking in with a healthcare provider before starting a new exercise routine is always a good idea. This is especially true if you have health conditions or take medications that may affect performance.
A Word About Exercise, Nutrition, Eating Disorders, and How to Get Help
Sometimes, exercise and diet plans can lead to disordered eating habits or even eating disorders.
Eating disorders can affect anyone. Several factors go into the development of an eating disorder, including biological, behavioral, psychological, and social factors.
Exercise and dieting often go hand in hand. Dieting for the purpose of weight loss has been shown to increase the risk of developing an eating disorder in some people.
If you're concerned that you (or a friend or family member) are at risk for developing an eating disorder, then it's vital to seek help as soon as possible. Eating disorder recovery involves help from loved ones and healthcare professionals.
You can find resources and qualified healthcare professionals through the National Eating Disorder Association (NEDA).
Summary
Studies show that pre- and post-workout nutrition play a critical role in your exercise routine. While pre-workout nutrition sets you up for a high-performance workout, post-workout nutrition helps you recover and build muscle.
It may be okay to fast before certain types of exercise, such as short or low-intensity workouts, but long or intense workouts typically require a pre-workout meal or snack.
After exercise, eating within six hours is recommended, but some people may find more benefits from eating right away.
Macronutrient ratios and dietary supplements are other factors to consider surrounding your workouts.
Depending on medical conditions, some people may need to make additional adjustments to their pre- and post-workout nutrition.
Talk with a healthcare provider to learn more about what to eat before or after a workout.
Read the original article on Verywell Health.
