Scheduling of eccentric lower"limb injury prevention exercises during the soccer micro"cycle : which day of the week?

Scheduling eccentric"based injury prevention programs (IPP) during the common 6"day micro"cycle in soccer is challenged by recovery and tapering phases. This study profiled muscle damage, neuromuscular performance, and perceptual responses to a lower limb eccentric"based IPP administered 1 (MD+1) vs 3 days (MD+3) postmatch. A total of 18 semi"professional players were monitored daily during 3 in"season 6"day micro"cycles, including weekly competitive fixtures. Capillary creatine kinase concentration (CK), posterior lower limb isometric peak force (PF), counter"movement jump (CMJ) performance, and muscle soreness were assessed 24 hours prior to match"day (baseline), and every 24 hours up to 120 hours postmatch. The IPP consisted of lunges, single stiff leg dead"lifts, single leg"squats, and Nordic hamstring exercises. Performing the IPP on MD+1 attenuated the decline in CK normally observed following match play (CON: 142%; MD+3: 166%; small differences). When IPP was delivered on MD+3, CK was higher vs CON and MD+1 trials on both MD+4 (MD+3: 260%; CON: 146%; MD+1: 151%; moderate differences) and MD+5 (MD+3: 209%; CON: 125%; MD+1: 127%; small differences). Soreness ratings were not exacerbated when the IPP was delivered on MD+1, but when prescribed on MD+3, hamstring soreness ratings remained higher on MD+4 and MD+5 (small differences). No between"trial differences were observed for PF and CMJ. Administering the IPP in the middle of the micro"cycle (MD+3) increased measures of muscle damage and soreness, which remained elevated on the day prior to the next match (MD+5). Accordingly, IPP should be scheduled early in the micro"cycle, to avoid compromising preparation for the following match.