Boosting Metabolism: The Role of Exercise and Nutrition

Metabolism is the set of chemical reactions that take place in a living organism. These metabolic reactions are accompanied by energy changes, which provide the energy required by the body to carry out basic functions (BMR). Such processes include breathing, cell rebuilding and the digestion of food.

How can physical exercise be a powerful factor in modifying metabolic rate?

1. As our physical activity increases, so do the body’s energy requirements. In this way, metabolism responds to this demand and provides the increased energy the body needs.
2. Exercise also changes the metabolism not only of the muscles being exercised, but also of other organs and tissues (such as adipose tissue and the liver).
3. During exercise, the changes induced continue to be maintained after it has finished, meaning that the increased rate of energy expenditure also continues.
4. The breakdown of carbohydrates and lipids is further enhanced through exercise.
5. Regular exercise and training significantly modify the metabolic profile. Muscle tissue has the ability to burn more calories than adipose tissue. Therefore, strength exercises for all the body’s major muscle groups contribute to increasing muscle mass.

As mentioned above, exercise causes major changes in our body and metabolism. However, the most important factor that simultaneously affects exercise performance, metabolism and health is nutrition. A balanced diet tailored to your needs and goals effectively supports the body’s energy requirements and expenditure. We should therefore bear in mind that an energy source (a food) contributes to meeting the demands of exercise.

How does our dietary behaviour determine metabolic rate?

1. Food has a thermogenic effect on the body. In other words, the processes involved in its digestion and absorption activate metabolism in order to use it as an energy source. Proper meal distribution keeps blood sugar levels stable, avoiding undesirable fluctuations in insulin.
2. Restrictive low-calorie diets have temporary results and noticeably reduce metabolic rate. On the other hand, a balanced diet rich in fibre, protein and nutrients increases metabolic energy expenditure. Combined with regular exercise, this provides better long-term results and more energy for everyday activities.
3. The body’s needs vary according to physical activity. Carbohydrate stores are depleted during exercise, and if they are not replenished, performance declines. Moderate-intensity exercise, or high-intensity exercise lasting more than one hour, reduces muscle glycogen stores and has negative effects on metabolic rate.
4. Hydration helps metabolism function more effectively. Our cells need water to carry out essential body functions, such as thermoregulation, the removal of waste metabolic by-products and nutrient transport. The body’s water requirements also vary according to our physical activity.
5. Finally, a balanced diet contributes to muscle recovery. By consuming the necessary amount of protein according to our needs, muscle tissue is rebuilt and we are protected from potential injuries that may be caused by exercise. Conversely, if the amount consumed is insufficient, proteins are broken down and metabolic activity is reduced.

Sources: Exercise Biochemistry Book – Exercise Biochemistry / Vassilis C. Mougios

Edited by: Maria Vasileiadou

Undergraduate student, Department of Physical Education and Sport Science