Achieving Energy Balance Through Exercise
Energy Balance is the ratio of energy taken in to energy expended. Food adds energy, and basic living processes expend energy. When energy intake in the form of calories from food equals energy output, weight is maintained. When energy intake exceeds output, extra calories are stored as fat and weight gain results. If output is greater than input, stored energy is used to make up for the lack, resulting in weight loss.
Is There Any Flexibility in the System?
There is quite a bit of flexibility in the system! The body can adjust itself through hormonal and physical changes to make up for small deviations from the norm, thus maintaining constant weight. If the amount of calories consumed is too small, the body compensates by slowing basal metabolic rates, if too great, speeding it up. People who don't eat enough often feel sluggish as their bodies slow down to conserve energy, whereas those who've taken in a bit much may have an excess bursts of energy. However, the body's flexibility has its limits. Push the bounds too far, and weight gain or loss is inevitable.
What Factors Go Into Energy Expenditure?
Basal metabolism uses up most of our energy. This is the energy required just to live such as sustaining constant body temperature and maintaining the function of the vital organs. The brain, especially, is very high maintenance, requiring a disproportionately large amount of energy to keep it functioning. Basal metabolism accounts for roughly sixty to seventy percent of total energy expenditure.
Digesting food also takes energy. About ten percent of all calories consumed go into breaking down the rest of the food. Different foods require different amounts of energy to utilize. Proteins take the most energy to use, whereas fats require almost none. Thus what you eat will affect how much energy your body is putting into using it.
Activity accounts for the remaining twenty to thirty percent of energy expenditure. The more activity, the more energy is used up. This is why exercise is such an important part of maintaining or altering energy balance. The food you eat determines how much energy you're taking in, whereas the activities you engage in determine how much you use up. If you want to lose weight, you have to eat less and exercise more, it's that simple. If you want to gain weight, you do the exact opposite. To maintain weight, keep your caloric intake and activity level at their current level.
How Do Different Types of Exercise Affect Energy Balance?
Does all physical exercise have the same impact on energy balance? Nope!
Aerobic exercise, where movement is key, is energy intensive and thus requires more energy immediately. It also elevates basal metabolic rates for a few hours afterwards. Aerobic exercise such as weight lifting, however, does not require as much energy to do. However, anaerobic exercise builds lean muscle. Lean muscle uses more energy, even when at rest. Therefore, while you might not burn as many calories right away, over time anaerobic exercise can burn just as many calories as aerobic exercise, perhaps more. It is important to incorporate both types of exercise into any fitness routine, since aerobic exercise is very beneficial to the cardiovascular system and increases endurance, whereas anaerobic exercise will increase muscle mass.