Best practice recommendations for body composition considerations in sport to reduce health and performance risks: a critical review, original survey and expert opinion by a subgroup of the IOC consensus on Relative Energy Deficiency in Sport (REDs).

BACKGROUND: The assessment of body composition (BC) in sport raises concern for athlete health, especially where an overfocus on being lighter or leaner increases the risk of Relative Energy Deficiency in Sport (REDs) and disordered eating. METHODS: We undertook a critical review of the effect of BC on performance (29 longitudinal, prospective or intervention studies) and explored current practice related to BC considerations via a follow-up to a 2013 internationally distributed survey. RESULTS: The review found that a higher level of body fat was negatively associated with endurance performance, while a gain in muscle mass resulted in performance benefits across sports. BC did not contribute to early talent identification, and no unique cut-off to signify a performance advantage for BC was identified. BC appears to be one of an array of variables impacting performance, and its influence should not be overstated. The survey (125 practitioners, 61 sports and 26 countries) showed subtle changes in BC considerations over time, such as an increased role for sport dietitian/nutrition practitioners as BC measurers (2013: 54%, 2022: 78%); less emphasis on reporting of body fat percentage (2013: 68%, 2022: 46%) and reduced frequency of BC assessment if ≥every fourth week (2013: 18%, 2022: 5%). Respondents remained concerned about a problematic focus on BC (2013: 69%, 2022: 78%). To address these findings, we provide detailed recommendations for BC considerations, including an overview of preferable BC methodology. CONCLUSIONS: The 'best practice' guidelines stress the importance of a multidisciplinary athlete health and performance team, and the treatment of BC data as confidential medical information. The guidelines provide a health focus around BC, aiming to reduce the associated burden of disordered eating, problematic low energy availability and REDs.

Can alternating lower body negative and positive pressure during exercise alter regional body fat distribution or skin appearance?

The purpose of this study was to determine whether physical activity, with and without lower body pressure, leads to increased regional fat loss in the lower extremities of overweight females. Eighty-six obese women with a female phenotype were randomly assigned into four groups: control group (C), diet only (D), diet plus exercise (DE) or diet, exercise and lower body pressure intervention (DEP). The three treatment groups followed the same diet, the two exercise groups (DE and DEP) additionally followed an endurance training program of 30 min of cycling at 50%VO(2)max three times per week with or without lower body pressure. Body composition and fat distribution were assessed by DXA. Body size circumference measurements were recorded as well as subjective ratings of cellulite and skin appearance. As expected, all test groups (D, DE, DEP) showed a significant decrease (p < 0.05) in total body mass and fat mass. DXA revealed significant differences between the experimental groups and C. The DEP group also lost significantly more body mass and fat mass when compared with D, while no significant difference was observed between the other groups. A similar pattern was seen for circumference measurement data. A significant perceived improvement was made by the DEP group when compared with C, D and DE groups for skin condition and also between the DEP versus C and D groups for cellulite. The combination of diet and exercise is successful for weight reduction. The additional application of lower body pressure especially affects skin appearance.