Does Resistance Training Improve Body Composition Changes During Low-Calorie Dieting?

Resistance training prevents muscle mass loss and improves fat loss during weight loss via calorie restriction.

Overview

• What did they test? The researchers tested the effects of a whole-body resistance training routine performed two to three times per week, compared with aerobic training or no exercise, on body composition changes during a hypocaloric weight-loss diet.
• What did they find? The findings of this study showed that people who engaged in resistance training while following a hypocaloric diet for an average of 5 months lost similar amounts of weight, but lost more body fat and gained lean mass compared to those who did cardiovascular exercise or no exercise.
• What does it mean for you? Hypocaloric dieting is an effective method to reduce body mass, however, it can lead to unwanted loss of lean mass. Eating enough protein and resistance training are two methods for combating reductions in lean mass.
  
  This study showed that adding resistance training to a hypocaloric diet that provided sufficient protein prevented loss of lean mass and increased fat loss over a period of 5 months. These findings further support the importance of engaging in resistance training to optimize changes in body composition while undergoing calorie restriction.

What’s the Problem?

Nearlty 70% of the US population is currently classified as overweight or obese 1 and this is associated with shorter life span, increased rates of heart diseaes, cancer, diabetes, dementia, and more 2. Hypocaloric dieting is the most effective way to reduce body mass, however, many people experience significant loss of lean mass while dieting 3. 

Further, repeated cycles of weight loss and weight regain can compound to negatively impact body composition. Loss of lean mass that occurs during weight loss is often at least partially replaced by fat mass when weight is regained 4. This is why it is imperative to minimize lean mass loss during weight loss. 

High-protein diets and resistance training are the two primary methods for reducing lean mass loss during low-calorie dieting 3. Several studies have shown positive effects of maintaining a sufficient protein intake and engaging in resistance training for preventing loss of lean mass and maximizing fat loss in a variety of populations. 

Purpose

Minimizing loss of lean mass and maximizing fat loss during hypocaloric dieting is ideal for health and body composition. The purpose of this study is to compare the effects of resistance training completed 2-3 days per week during a hypocaloric diet to engaging in aerobic exercise or no exercise at all on changes in body composition. The study also aimed to determine if there were sex specific differences in responses. 

Hypothesis

The authors did not present a hypothesis for this experiment.

What Did They Test and How?

Participants