Eating to Support Exercise

When trying to lose weight, gain muscle, or grow our fitness level in any way it is important to be informed about how to eat. Most people, especially when they are trying to lose weight, skip fueling physical activity because they think it will allow their body to burn the most calories. This is actually misguided thinking. Research shows that results from exercising are actually increased when properly fueled by nutrition before, after, and during a workout. In fact, studies have shown that there is no weight difference between people who eat versus people who don’t eat in times surrounding exercise. However, there is increased injury associated with exercising in a starved state. 

Below we briefly outline the general recommendations of how to best eat surrounding physical activity to help you be informed about when, what, and why to eat before, after and during exercising. This is by no means an exhaustive list but is information to help you get started in the right direction. 

Before Exercise

When and why to eat before:  Before any workout your body wants one thing: energy. Energy to get through a workout, energy to use all your muscles, and energy to recover during breaks. We eat before exercise in order to provide our bodies with the energy it craves within the 30-60 minutes before a workout. This is especially important when exercising with moderate to hard intensity for 45-60 minutes or more. Providing our stomachs with fuel before a longer workout like this gives us energy ready to be used and allows our bodies to reach their full calorie burning and muscle building potential. 

What to eat: The quickest way for your body to get energy is through carbohydrates. Ideally, 30 minutes to one hour before each workout you should consume 15- 30 grams of simple carbohydrates. Yes, you read that right, this is the one scenario where a fiber rich carbs are not the answer since it will more than likely result in an upset stomach. Instead, eating simple carbs can be used quickly by the body for energy without upsetting our digestive system. 

Examples: applesauce, saltine crackers, fig bars, white toast, etc. 

After Exercise

When and why to eat after: During exercise, especially exercise lasting 60 minutes or longer, your body goes through a lot. Both cardio and weight bearing activities break down our muscles and use up glycogen stores. Afterwards, as our heart and skeletal muscles are rebuilding, is when we gain strength, stamina, and fitness. In order to aid in this rebuilding, it is important that we refuel ourselves intentionally and in a timely manner in order to see the best results. When we don’t refuel well and leave our stomach empty, instead of using food to rebuild our muscles, our bodies will instead break down other sources (i.e. joints, muscles, etc.) to replenish itself instead. As a result, people who don’t eat enough after exercising are much more likely to experience increased rates of injury and muscle fatigue. 

What to eat: Rebuilding muscles after a physical activity requires energy and building blocks. As a result, carbs and protein are the best foods to serve this purpose for us. Within 30-60 minutes after exercise it is best to eat carbs and protein in a 3:1 ratio (3 grams of carbohydrates for every 1 gram of protein). This ensures that you are giving your body the right portions of the foods it needs to heal and grow stronger. 

Examples: peanut butter with a banana and honey, protein shake, Greek yogurt with granola, etc.

During Exercise

When and why to eat during: Eating during exercise is important whenever you are performing moderate/hard intensity exercise for 60 minutes or more. The reason for this is that after 60 minutes your body has used up all of it’s glycogen stores (quick energy storage) and will start breaking down your muscles and joints if it doesn’t have other fuel to go off of. So in these types of workouts fueling during exercise helps prevent injury and keeps you feeling your best for however long you need. 

What to eat: What to eat during exercise changes slightly with the type of activity you are doing. However, as a general rule of thumb you need 15 g of simple carbohydrates every 30-45 minutes. Just like with eating beforehand, you want these foods to be sources of quick energy and electrolytes that can be used immediately. 

Examples: 4 ounces Gatorade/Powerade, sports gels, M&Ms, dried fruit, etc. 

Adjusting for your body 

When starting to fuel our exercise better our bodies will always need an adjustment period. If you go from eating nothing before or during your workouts and then overnight start eating large portions of food surrounding every activity, then more than likely you will end up experiencing an upset stomach and muscle pain. Instead, gradually increase nutrient intake so your body has time to adjust and re-learn what it should be using as fuel and replenishment. 

This is not to say that the same food will work for everyone. Everyone's body is slightly different and even if you increase food intake super slow, there may be certain foods and time frames you have an adverse reaction to. It’s all about learning your body and what works best for you. Trial and error is the best way to figure out what works for your stomach. Focus on the parameters outlined above and try out all different timing and foods until you find what fits.