Impact of Diet on Resistance Training Benefits

Introduction

A recent study from Brazil, published in PLOS One, highlights the significant role diet plays in influencing the benefits derived from resistance training. Both exercise and diet are essential elements in promoting overall health, with numerous studies confirming their effectiveness in preventing and managing various diseases. Specifically, diet and physical activity are strong predictors of obesity and key metabolic health indicators, including insulin sensitivity and lipid profiles.

Exercise and Health Maintenance

Aerobic exercise and resistance training both contribute positively to health maintenance. While aerobic training is often linked more closely to weight loss, resistance training is recognized for its ability to reduce body fat and increase muscle mass. This shift in body composition can subsequently lower disease risk.

The Connection Between Diet and Exercise

The interplay between diet and the advantages of physical exercise is well-established. This relationship has spurred the popularity of specific exercise-diet combinations aimed at weight management. For example, low-carbohydrate, high-fat diets (LCD) are frequently adopted to encourage rapid weight loss, particularly when paired with resistance training. Nonetheless, some studies indicate that LCD may lead to weight and fat regain over time and could adversely affect metabolic health factors, including insulin and glucose levels.

Research on Resistance Training and Low-Carb Diets

Despite the existing literature, limited research has explored the long-term health effects of combining resistance training with LCD. The recent Brazilian study sought to investigate how resistance training, in conjunction with a long-term LCD, influenced body weight, fat deposition, and metabolic health in rats.

Study Design

In this study, rats were placed on either a standard diet or an LCD for a duration of 21 weeks. The standard diet consisted of 9% fat, 76% carbohydrates, and 15% protein, while the LCD included 59% fat, 31% carbohydrates, and 10% protein. After 10 weeks, the rats were divided into sedentary and resistance-trained groups. The sedentary group remained inactive, whereas the resistance-trained group participated in an 11-week exercise program involving climbing vertical ladders with increasing weights. Throughout the experiment, researchers monitored body weight, food intake, and various health indicators.

Findings on Low-Carb Diet and Resistance Training

The findings revealed that resistance training contributed to a reduction in body weight and liver fat for both the standard diet and LCD groups. However, resistance-trained rats on a standard diet exhibited decreased abdominal fat, lower LDL cholesterol levels, and increased muscle mass compared to their sedentary peers. Conversely, those on the LCD did not experience similar reductions in fat mass or muscle improvements. Additionally, LCD-fed rats showed increased insulin resistance, reducing their ability to lower blood glucose levels. This impairment was partially attributed to the decrease in muscle mass, which plays a crucial role in helping insulin manage glucose in the bloodstream, thereby heightening the risk of obesity and type 2 diabetes.

Need for Further Research

While the long-term LCD had beneficial effects on body weight, the study concluded that it hindered the benefits of resistance training concerning fat loss, muscle composition, and blood glucose regulation. The authors recommend further clinical studies on humans to validate these findings, particularly regarding insulin resistance in specific body tissues.

Reference

Stotzer US, Pisani GFD, Canevazzi GHR, Shiguemoto GE, Duarte ACGO, Perez SEA, et al. Benefits of resistance training on body composition and glucose clearance are inhibited by long-term low carbohydrate diet in rats. PLoS One [Internet]. 2018 Dec [cited 2018 Dec 29];13(12):e0207951. Available from: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0207951 doi: https://doi.org/10.1371/journal.pone.0207951