Precipitation Of Muscle Damage In Females Following A Sport-specific Bout Of Repeated Sprints

Abstract

High intensity eccentric contractions can result in exercise-induced muscle damage (EIMD), the symptoms of which are temporary, but last for several days following the initial bout. Although the responses have been well described in the literature, there is a paucity of data surrounding this response in females. PURPOSE: The aim of this study was to examine the damage responses from a sport-specific bout of repeated sprints on well-trained collegiate female athletes. METHODS: Eleven well-trained females (mean ± SD; age 22 ± 3 y, height 166.6 ± 5.7 cm, mass 62.7 ± 4.5 kg) took part in a repeated sprint protocol designed to induce EIMD (15 by 30 m sprints, with an enforced deceleration, and a 60 s rest period between repetitions). Markers of EIMD were assessed before and up to 72 hours following the repeated sprint protocol. These included creatine kinase (CK), jump height (CMJ), maximum voluntary contractions (MVC), sprint times, limb girth and muscle soreness (DOMS). All participants were tested throughout the luteal phase of the menstrual cycle. RESULTS: CK was elevated at 24, 48 and 72 h (p≤0.035), peaking at 24 h (+418%) and returning towards baseline at 72 h. CMJ significantly reduced immediately post, 24 and 48 h (p<0.05) post exercise, with a mean jump height decline of 12% from pre exercise (26.4 ± 3.3 cm) to immediately post exercise (23.4 ± 4 cm). Sprint performance was also negatively affected immediately post, 24 h, 48 h and 72 h post exercise, nadir at 48 h (5.25 ± 0.4 s) equating to a 6 % increase from pre exercise times. Muscle soreness peaked at 48 h (p<0.001) and stayed significantly elevated at 72 h post exercise (p<0.003). Limb girth or MVC did not alter over time. CONCLUSIONS: The current study demonstrates that a sport specific bout of repeated sprints precipitates EIMD in trained females and has the potential to negatively affect performance in the subsequent days, which is evidenced by decrements in muscle function and soreness. Further research is needed to examine the damage responses in this population following other damaging exercise paradigms, and importantly if the menstrual cycle influences the EIMD response.