Neuromuscular Fatigue and Muscle Damage After a Women's Rugby Sevens Tournament

Abstract

PURPOSE: To examine relationships between on-field game movement patterns and changes in markers of neuromuscular fatigue and muscle damage during a 2-d women's rugby sevens tournament. METHODS: Female national (mean ± SD n = 12, 22.3 ± 2.5 y, 1.67 ± 0.04 m, 65.8 ± 4.6 kg) and state (n = 10, 24.4 ± 4.3 y, 1.67 ± 0.03 m, 66.1 ± 7.9 kg) representative players completed baseline testing for lower-body neuromuscular function (countermovement-jump [CMJ] test), muscle damage (capillary creatine kinase [CK]), perceived soreness, and perceived recovery. Testing was repeated after games on days 1 and 2 of the tournament. GPS (5-Hz) data were collected throughout the tournament (4-6 games/player). RESULTS: National players were involved in greater on-field movements for total time, distance, high-speed running (>5 m/s), and impacts >10 g (effect size [ES] = 0.55-0.97) and displayed a smaller decrement in performance from day 1 to day 2. Despite this, state players had a much greater 4-fold increase (δCK = 737 U/L) in CK compared with the 2-fold increase (δCK = 502 U/L) in national players (ES = 0.73). Both groups had similar perceived soreness and recovery while CMJ performance was unchanged. High-speed running and impacts >10 g were largely correlated (r = .66-.91) with δCK for both groups. CONCLUSION: A 2-day women's rugby sevens tournament elicits substantial muscle damage; however, there was little change in lower-body neuromuscular function. Modest increases in CK can largely be attributed to high-speed running and impacts >10 g that players typically endure.