Recovery and adaptation from repeated intermittent sprint exercise

PURPOSE: This investigation aimed to 1) ascertain a detailed physiological profile of recovery from intermittent sprint exercise on athletes familiar with the exercise, and 2) investigate if athletes receive a protective effect on markers of exercise-induced muscle damage (EIMD), inflammation and oxidative stress following a repeated exposure to an identical bout of intermittent sprint exercise. METHODS: Eight well trained male team sport athletes of National League or English University Premier Division standard (mean ± SD age 23 ± 3 years; VO2max 54.8 ± 4.6 ml·kg-1·min-1) completed the Loughborough Intermittent Shuttle Test (LIST) on two occasions, separated by 14 days. Maximal isometric voluntary contraction (MIVC), counter-movement jump (CMJ), creatine kinase (CK), C-reactive protein (CRP), interleukin-6 (IL-6), F2-isoprostanes and muscle soreness (DOMS) were measured before, and up to 72 h following the initial, and repeated LIST. RESULTS: MIVC, CMJ, CK, IL-6 and DOMS all showed main effects for time (P <0.05) following the LIST indicating EIMD was present. DOMS peaked at 24 h following LIST 1 (110±53 mm) and was attenuated following LIST 2 (56±39 mm), and was the only dependent variable to demonstrate a reduction in the second bout (P = 0.008). All other markers indicated EIMD were not different between bouts. CONCLUSION: Well-trained games players experienced EIMD following exposure to both exercise tests, despite being accustomed to the exercise type. This suggests well-trained athletes receive a very limited protective effect from the first bout.