Abdominal adiposity distribution in elite rugby union athletes using magnetic resonance imaging

Training and Competition Loads in Women's Rugby Sevens Athletes: Are There Implications for Cardiovascular Health?

National- and international-level rugby sevens athletes are exposed to high training and competition loads over the course of a competitive season. Research on load monitoring and body-system responses is widespread; however, the primary focus has been on optimizing performance rather than investigating or improving cardiovascular health. There is a degree of cardiovascular remodeling, as well as local and systemic inflammation, in response to excessive exercise. These responses are moderated by many factors including previous exercise exposure, current exercise intensity and duration, age, race, and gender, as well as sport-specific physiology. For these reasons, high-performing female rugby sevens athletes may have a unique cardiovascular risk profile different from males and other rugby codes. This review aimed to characterize the training and competition loads, as well as the anthropometric and physiological profiles, of female rugby sevens athletes; discuss the potential impacts these may have on the cardiovascular system; and provide recommendations on future research regarding the relationship between rugby sevens training and competition loads and cardiovascular health. Movement demands, competition formatting, and training routines could all contribute to adverse cardiovascular adaptations. Anthropometric data and physiological characteristics may also increase the risk of cardiovascular disease. Future research needs to adopt measures of cardiovascular health to obtain a greater understanding of cardiovascular profiles and risk factors in female rugby sevens athletes.

Increases in DXA-Derived Visceral Fat Across One Season in Professional Rugby Union Players: Importance of Visceral Fat Monitoring in Athlete Body Composition Assessment

INTRODUCTION

In rugby, the average player body mass has increased by approximately 25% since 1955. Visceral adipose tissue (VAT) is associated with low grade inflammation, and chronic diseases, such as cardiovascular diseases. The purpose of this study was to investigate changes in VAT in relation to other indices of body composition, across 1 season in professional rugby.

METHODOLOGY

One hundred and sixteen male rugby union players' (age: 26.2 ± 4.6 y, BMI: 29.40 ± 3.22 kg.m²) total body composition dual energy X-ray absorptiometry scans from 4 time points across the season (baseline, preseason, midseason, and postseason) were analyzed. Players were grouped by playing position, forwards (n = 65) and backs (n = 51). Players followed individually tailored diet plans.

RESULTS

Mean baseline VAT was 404.67 ± 229.43 g (forwards: 469.36 ± 263.16 g, backs: 311.40 ± 121.15 g). Total mass, lean mass, body fat percentage (%BF), and VAT were greater in forwards than backs at all 4 timepoints. Meaningful increases in VAT across the season, were observed in 37.5% of backs and 53.6% of forwards. There was a positive linear relationship between lean mass and total mass, up to 116.04 kg total mass. Beyond this threshold, lean mass accumulation reduced and %BF and VAT mass increased. There were significant relationships between %BF, VAT, and BMI (p < 0.001), but no physiological relevant pattern was discerned.

CONCLUSIONS

Despite regular high-intensive exercise and individually tailored dietary control across a professional rugby season, players from both playing positions demonstrated increases in VAT, although the cause remains unknown. Our findings indicate the importance of monitoring VAT in athletes alongside standard measures of body composition. Additionally, our findings suggest there may be an upper threshold of body mass beyond which lean mass may not increase further and instead %BF and VAT are more likely to accumulate. Further research is required to identify how increasing player size may impact long-term cardiometabolic health given the known links between VAT and cardiometabolic risk.

The Physical Characteristics of Elite Female Rugby Union Players

This study explored the anthropometric and body composition characteristics of elite female rugby union players, comparing between and within different playing positions. Thirty elite female rugby union players (25.6 ± 4.3 y, 171.3 ± 7.7 cm, 83.5 ± 13.9 kg) from New Zealand participated in this study. Physical characteristics were assessed using anthropometric (height, body mass, skinfolds) and body composition (dual-energy X-ray absorptiometry) measures. Forwards were significantly taller (p < 0.01; d = 1.34), heavier (p < 0.01; d = 2.19), and possessed greater skinfolds (p < 0.01; d = 1.02) than backs. Forwards also possessed significantly greater total (p < 0.01; d = 1.83–2.25) and regional (p < 0.01; d = 1.50–2.50) body composition measures compared to backs. Healthy bone mineral density values were observed in both forwards and backs, with significantly greater values observed at the arm (p < 0.01; d = 0.92) and femoral neck (p = 0.04; d = 0.77) sites for forwards. Tight-five players were significantly heavier (p = 0.02; d = 1.41) and possessed significantly greater skinfolds (p < 0.01; d = 0.97) than loose-forwards. Tight-five also possessed significantly greater total body composition measures (p < 0.05; d = 0.97–1.77) and significantly greater trunk lean mass (p = 0.04; d = 1.14), trunk fat mass (p < 0.01; d = 1.84), and arm fat mass (p = 0.02; d = 1.35) compared to loose-forwards. Specific programming and monitoring for forwards and backs, particularly within forward positional groups, appear important due to such physical characteristic differences.

Body composition differences by age and playing standard in male rugby union and rugby league: A systematic review and meta-analysis

This systematic review and meta-analysis aimed to determine differences in body compositionn between playing standard and age in male rugby union and rugby league athletes. The MOOSE (Meta-analysis of Observational Studies in Epidemiology) guidelines for design, implementation, and reporting were followed. Studies were required to be in male rugby union or league and have body composition as the primary or secondary outcome. Data was required to be presented separately for positional groups and body composition presented as whole-body. A systematic search was performed in PubMed, Cochrane Library, MEDLINE, SPORTDiscus, and CINHAHL via EBSCOhost. 57 studies were included for meta-analysis. Results highlighted significantly higher fat-free mass in senior elite than senior sub-elite or junior elite athletes for all RU and RL forwards. Small and non-significant differences were found in fat mass between rugby union playing standards and age categories. Rugby league senior elite forwards had less fat mass than junior elite forwards. Practitioners should prioritise training and nutritional strategies that maximise fat-free mass development, especially in junior elite cohorts.

Physical and Fitness Characteristics of Elite Professional Rugby Union Players

This study explored the physical and fitness characteristics of elite professional rugby union players and examined the relationships between these characteristics within forwards and backs. Thirty-nine elite professional rugby union players from the New Zealand Super Rugby Championship participated in this study. Body composition was measured using dual-energy X-ray absorptiometry alongside anthropometrics. Fitness characteristics included various strength, power, speed, and aerobic fitness measures. Forwards were significantly (p ≤ 0.01) taller and heavier than backs, and possessed greater lean mass, fat mass, fat percentage, bone mass, and skinfolds. Forwards demonstrated greater strength and absolute power measures than backs (p = 0.02), but were slower and possessed less aerobic fitness (p ≤ 0.01). Skinfolds demonstrated very large correlations with relative power (r = −0.84) and speed (r = 0.75) measures within forwards, while backs demonstrated large correlations between skinfolds and aerobic fitness (r = −0.54). Fat mass and fat percentage demonstrated very large correlations with speed (r = 0.71) and aerobic fitness (r = −0.70) measures within forwards. Skinfolds, fat mass, and fat percentage relate strongly to key fitness characteristics required for elite professional rugby union performance. Individual and positional monitoring is important due to the clear differences between positions.

Differences in visceral adipose tissue and biochemical cardiometabolic risk markers in elite rugby union athletes of Caucasian and Polynesian descent

Polynesian individuals are leaner with greater musculature than Caucasians of an equivalent size, and this genetically different morphology provides a physique that is often compatible with success in a number of sports, including rugby union. Evidence indicates that Polynesians have greater stores of absolute and relative abdominal fat mass and this is known to confer cardiometabolic risk. The aims of this study were to (1) explore the relationship between ethnicity, visceral adipose tissue (VAT), and cardiometabolic disease risk markers in elite Caucasian and Polynesian rugby union athletes, and (2) assess the impact of a pre-season training programme on these markers. Twenty-two professional rugby union athletes of Caucasian (n = 11) and Polynesian (n = 11) descent underwent physique assessment via surface anthropometry, dual-energy X-ray absorptiometry, and magnetic resonance imaging before and after an 11-week pre-season. A fasted blood test was undertaken at both time points. Compared to Caucasians, at baseline Polynesians displayed significantly higher VAT (771 ± 609 cm³ vs 424 ± 235 cm³; p = 0.043), triglycerides (1.0 ± 0.9 mmol/L vs 0.6 ± 0.2 mmol/L; p = 0.050), and low-density lipoprotein cholesterol (3.1 ± 0.9 mmol/L vs 2.3 ± 0.7 mmol/L; p = 0.019). Similar changes were observed in both groups over the pre-season period in VAT and blood biochemical markers. Polynesian rugby union athletes were more likely than Caucasians to exhibit risk factors associated with cardiometabolic disease, such as elevated VAT and unfavourable lipid profiles. Further longitudinal research is required to identify and explain the short- and long-term risk of cardiometabolic disease in athletes of Polynesian descent.