Food For Exercise
The Basics
Unfortunately in our age of fast food consumerism, we tend to forget that we must balance exercise and proper nutrition to remain healthy. The amount and type of food we eat can either assist or deter your fitness and health goals. Essentially, we are what we eat. We need food for three primary reasons:
- To use as energy;
- Tissue growth and repair; and
- To fuel and regulate the cells in our body
Food can be categorized into six main groups: carbohydrates, fats, proteins, vitamins, minerals, and water. Each of these nutrients has unique roles in our bodies. For example, carbohydrates and fats are mainly responsible for energy production, whereas proteins, vitamins, minerals and water are required for tissue growth and repair and cellular functions.
Food: The Energy for Exercise
When we are at rest, we burn roughly 70% fats and 30% carbohydrates as energy to power our metabolic needs. During exercise however, these values will vary with the training intensity and duration. For instance, when intensity increases, the fraction of carbohydrates burned increases. If the intensity drops and the exercise duration increases, then fats will be more favored. As your physical fitness improves, so does your ability to burn fats more efficiently. This means that fats will be burned even at higher workout intensities.
Although we have a lot of stored fat in our bodies, we only have a limited reserve carbohydrate (enough to supply about 90 minutes or moderate activity or 30 minutes of intense exercise). Once this carbohydrate store is depleted, the body will turn to fats for its fuel source. However, if your glycogen (carbohydrate) remains empty for long periods of time, muscle protein will begin to break down for energy as well. Thus, it is imperative to have a high carbohydrate diet to replenish your glycogen supply and avoid this muscle breakdown.
Our fuel mix for energy is constantly shifting and depends on the following factors:
- The amount of nutrients already stored
- The duration and intensity of the physical activity
- Your personal fitness level
Advice for Healthy Eating
The Canada Health Guide recommends that no more that 30% of our diet should come from fats. The following ranges are guidelines for the amount of food that should come from each fuel source in our daily diets. Of course, this is only an outline and could be modified for personal differences and training programs.
- 55-75% Carbohydrates
- 15-30% Fats
- 10-20% Proteins
