Health & Wellbeing

Metabolic Rate – what is it and why is important?

What is Metabolic Rate:

Metabolic rate refers to the total energy used of the body in order to function. A person’s metabolic rate is made up of a series of factors which include; basal metabolic rate (BMR), resting metabolic rate (RMR), the thermic effect of food and energy used during physical activity. These components combine to represent the total energy used by the body each day.

Basal metabolic rate (BMR) refers to the energy required for the body and its organs to operate when at complete rest. Here the energy of the body is used to operate the organs, maintain breathing, circulate the blood, repair muscle and tissue and adjust hormones. Due to the large number of systems and organs which work with in the body, the BMR accounts for 50-80% of the total daily energy used.

Resting metabolic rate (RMR) is similar to BMR but is instead the energy required to function when completing nonstrenuous tasks excluding exercise. Although they are different, RMR can be used instead of BMR however it will be slightly higher.

The thermic effect of food is simply the energy used by the body to breakdown and digest the food you eat before absorbing and transporting the nutrients to organs and muscles. This represents approximately 5-10% of the total energy used per day by the body.

The remaining energy is used during physical activity. This includes general activities such as walking and washing but also planned activities such sporting events and training. Depending on the amount of training and competing done, this can account for up to 20% of the body’s total energy expenditure per day.

Do you need to know your metabolic rate?

In short, no. However athletes and active individuals often have targets of losing or gaining weight, increasing muscle mass, and reducing fat stores. While training is an important part of developing a stronger physique, managing your diet and know your BMR can help to play a role in your success.

By knowing the energy the body requires to remain at its current state, an athlete can change their overall energy intake though adjusting protein, carbohydrates and fats consumption. This allows athletes to modify their body composition through increasing or decreasing weight, muscle mass and fat stores.

It is important to know that your BMR can change in response to your diet and fluctuations in muscle mass. Highly restrictive diets often lead to fast reductions in weight through reducing fat and carbohydrate intake. In an attempt to maintain its normal state, the BMR of the body slows in order to combat weight loss.

This is common for athletes who participate in bodybuilding competitions where they are required to ‘shred’ or lose as much fat as possible. To combat this, athletes may use refeeding days or take diet breaks, which slow the BMR’s response to the diet and prevent weight gain.

Although knowing your BMR can be useful, it is not necessary to improve diet quality and athletic performance. By simply improving diet quality, reducing unhealthy food choices, and adjusting the intake of protein, carbohydrates and fat, athletes can also meet the needs of their sport or reach their goals.

If you need assistance with your diet or some help to reach your goals, contact us today to find out how we can help you.