If a client begins a training/dieting program with you, understanding this process can help guide both his workouts and his meal planning. These changes initiate the cascade leading to a depressed metabolic level. Severely restricting calories forces hormonal adaptations to kick in during this “protective mechanism” mode, most notably affecting circulating levels of leptin, thyroid, and testosterone.
Keep in mind that BMR slows as weight goes down, requiring even fewer calories for maintenance. Therefore, determining a client’s BMR can help you estimate his/her caloric needs for losing weight.
Lean muscle tissue remains the body’s biggest BMR calorie burner. Calories utilized to metabolize food and to fuel activity comprise the remaining 40%. Surprisingly, our basal metabolic rate constitutes the majority of a body’s calorie needs - about 60 % of total energy expenditure, according to research from the University of Colorado at Denver. Protein intake was maintained at proper levels of 1.2 grams/kg still at the 3-week assessment, the men lost an average of 3.8 kg, half of which was lean muscle mass.įurthermore, at the end of the 21 days, the collective BMR dropped over 200 calories! Although aerobic capacity was not significantly impacted, muscle endurance did decline by 20%. In a 2005 study, Friedlander et al measured the results of restricting diet to 40% of caloric needs in nine young, healthy men for 3 weeks. This explains how severely restricting calories for purposes of weight loss almost always fails. This is an evolutionary process, much like a bear entering hibernation. In the case of grossly underfed bodies, or if too long between a period exists between meals - over three or four hours - the body slows its metabolic rate in an attempt to conserve energy. In desperate need of a fuel source, without enough energy, the body begins to tear down muscle tissue, generating a drop in lean muscle mass, despite efforts used during exercise. Insufficient caloric intake slows the body’s metabolism considerably. In a similar fashion, the body utilizes calories from food, or energy, in order to execute and maintain all of life’s functions. By putting fuel in a car, the engine runs efficiently, enabling the vehicle to move. Here’s why consuming below Basal Metabolic Rate (BMR) is a bad idea for even the most determined weight loss clients. Fat reserves get stored, to be utilized as energy until the body is once again appropriately nourished. However, this process often backfires when the body’s protective mechanism of entering “starvation mode” kicks in. Restricting calories below metabolic needs might initially sound like a surefire path to weight loss.
0 kommentar(er)
