The importance of fueling for exercise
With all of the supplements, protein powders, “energy boosters”, and biohacking nutrients on the market, it can be SO confusing how to make any sense of it all. And even harder to decide what actually is scientifically shown to be effective for fueling your workout. The good news is there is quite a bit of research on the macronutrients that you need to fuel your physical activity, whatever that might be!
But first, lets talk about the basics of fueling exercise.
Why do we need fuel for exercise?
Our bodies require energy to carry out all of our functions like breathing, thinking, talking, walking, and reading — like you are doing right now! We have to eat so that the sandwich you had for lunch can be digested and converted into usable sources of energy by our body. There are many complicated pathways in our body that do this, and these processes are called metabolism (more detail in a later blog post). The most important compound our body uses for energy is called ATP (adenosine triphosphate). Your body takes the protein, carbohydrates, and fat from food and makes ATP so that you can take your dog for a walk or run a marathon. Skimping on nutrition can reduce muscle mass, lower bone density and cause fatigue. If we don’t have enough energy (ATP) we often feel tired and the exercises we do feel much more challenging than if we had enough gas (food) in the tank!
Figure 1. Our body uses protein, carbohydrate and fats from food and breaks them down, or metabolizes them, in our muscle and liver to be converted into usable energy in the form of ATP (adenosine triphosphate).
What do I eat before exercise?
When we exercise our body prefers to use carbohydrates as the primary source of energy. That is because our bodies can convert carbohydrates to energy (ATP) most efficiently! If you were to go on a vigorous 30-minute bike ride, your body would first use its carbohydrate stores available. Next, our body will use the fat stores in our body to replenish ATP. Fat stores are the preferred source of energy during low-intensity exercise (like going on a long walk or hike). And lastly, our body will utilize protein if there is not enough carbohydrate or fat available to produce ATP. Protein is important for rebuilding muscle, so our body wants to preserve using protein to make energy as much as possible. However, adequate protein in the diet is important for rebuilding muscle before and after exercise. In summary, all three of these macronutrients are vital to producing energy in our body, especially during exercise!
It is widely accepted in the literature that we need about 60 grams of carbohydrate per 1 hour of endurance exercise. This carbohydrate intake should be consumed 1-4 hours before the activity. For example, if you were to go to a 1 hour cycle class, you would want to consume 60 g of carbohydrates 1-4 hours before the activity. Let’s say you work out in the morning and you generally don’t eat before your exercise. That’s okay! Our body is REALLY good at storing energy, so if you ate a carbohydrate rich meal the day before, you have some energy reserved in your liver and muscle for that morning exercise. (Note: these recommendations are not one-size-fits all and can vary widely from person to person)
Some examples of pre-workout meals include:
1 large bagel with peanut butter or cream cheese
Fruit smoothie with banana, berries, yogurt, milk (dairy or non-dairy)
Rice bowl with chicken and vegetables
What do I eat after exercise?
Fueling after exercise (post-workout) is just as important as fueling before exercise (pre-workout). In general, consuming a source of protein and carbohydrates ~30 minutes after exercise can help with your recovery after exercise. The protein is important for rebuilding the muscle after exercise and the carbohydrate is important for replenishing the stored energy you just used during your workout.
Most research suggests very active people should eat 1.2 to 2 grams of protein per kilogram of body weight. That means a 150-pound person should eat 82 to 136 grams each day. People who aren't active should eat less protein. Aim for .8 grams per kilogram of body weight each day. Good sources of protein are poultry (25 grams in 3 ounces) and fish (20 grams in 3 ounces). Those who prefer to avoid meat can try soybeans (20 grams per cup) and legumes like beans, peanuts and chickpeas (about 15 grams per cup). Eggs, Greek yogurt, cheese and tofu are good sources, too.
Some examples of these foods include:
A piece of toast with peanut butter
Yogurt and an apple
Oatmeal with a banana
Tuna and crackers
This summary for fueling exercise is just the tip of the iceberg and only covers the basics of macronutrient intake for exercise. There are many other important nutrients for exercise that benefit performance in other ways that I discuss in my other blog “Top 5 nutrients for improving exercise performance”.
Do you have questions or want more specific information on fueling for exercise? Feel free to contact me.
