A Cross-Sectional Study Assessing the Contributions of Body Fat Mass and Fat-Free Mass to Body Mass Index Scores in Male Youth Rugby Players

Olivier Gavarry,Guillaume Chaumet,Julien Piscione,Alain Boussuges,Patrick Pezery,Gregory Lentin,Anne Delextrat

doi:10.1186/s40798-018-0130-7

Olivier Gavarry, Guillaume Chaumet + Show 5 more

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https://doi.org/10.1186/s40798-018-0130-7

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Abstract

BackgroundIn some sports such as rugby, a large body size is an advantage, and the desire to gain weight can bring young players to become overweight or obese. The aim of this study was to evaluate the prevalence of overweight and obesity and the contribution of body fat mass index (BFMI) and fat-free mass index (FFMI) to body mass index (BMI) changes among young male rugby players (15-a-side rugby).MethodsThe criteria of the International Obesity Task Force were used to define overweight and obesity from BMI. The method of skinfold thickness was used to assess percentage of body fat (%BF), BFMI, and FFMI. Excess body fat was defined by using BFMI and %BF above the 75th percentile. Data were grouped according to the age categories of the French Rugby Federation (U11, under 11 years; U13, under 13 years; U15, under 15 years) and to BMI status (NW normal-weight versus OW/OB overweight/obese).ResultsOverall, 32.8% of the young players were overweight, and 13.8% were obese. However, 53% of young players classified as obese and overweight by BMI had an excess body fat by using BFMI above the 75th percentile. FFMI increased significantly between U11 and U13 in both groups, without significant change in BMI and BFMI. Both groups had similar significant gains in BMI and FFMI between U13 and U15, while BFMI only increased significantly in OW/OB (+ 18.5%). The strong correlations between BMI and %BF were systematically lower than those between BMI and BFMI. FFMI was strongly or moderately associated with BFMI.ConclusionsChart analysis of BFMI and FFMI could be used to distinguish changes in body composition across age categories in young male rugby players classified as normal-weight, overweight, and obese by BMI.

Highlights

In some sports such as rugby, a large body size is an advantage, and the desire to gain weight can bring young players to become overweight or obese
Similar prevalence of overweight and obesity was observed in under 11 years (U11) and under 13 years (U13)
For both overweight/obese and normalweight players, fat-free mass index (FFMI) increased significantly between U11 and U13 (NW: + 0.4 kg m−2/+ 2.8%, 95% confidence interval (CI) 0.8 to 0.0, d = 0.40, p < 0.001; overweight/obese players (OW/OB): + 0.7 kg m−2/+ 6%, 95% CI 1.5 to 0.2, d = 0.46, p = 0.02) and between U13 and under 15 years (U15)

Summary

Introduction

A large number of studies have evaluated the prevalence of childhood and adolescent obesity in sedentary children, there is a paucity of research in young athletes [3,4,5,6] In some sports such as rugby, a large body size is an advantage, and the desire to gain weight can bring young players to become overweight or obese. In another contact sport, Malina et al [4] observed a high prevalence of overweight and obesity among young American football players (42.6%). Childhood and adolescence obesity, characterized by reduced muscular strength in the lower limb [10] and lower aerobic fitness [11], can both result in a decrease in athletic performances

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