Effects of half-time re-warm-up strategies on injury markers during the 2nd half of soccer match-play

![CDATA[A high proportion of soccer injuries are sustained immediately following half-time (HT),1 potentially the result of reduced muscle temperature during the passive interval.2 Re-warm-up strategies during the interval to maintain muscle functioning and proprioception may therefore aid injury prevention. The purpose of this study was to investigate the effects of different HT strategies on subsequent markers of injury risk during a simulated game. Ten semiprofessional male soccer players (age: 20±1 years; body mass: 79.9±7.0 kg; VO2max: 60.5±4.2 ml kg−1 min−1) performed three randomised 90 min soccer simulations (SAFT90), using a fixed-intensity, multidirectional, intermittent exercise protocol. During the 15 min HT interval, players either remained seated (CON), or between 9 and 14 min performed intermittent agility exercise at 70% heart rate maximum (IAE), or intermittent exposure (3×60 s) to whole body vibration (WBV) in a static squat posture (frequency = 40 Hz; amplitude = 2 mm). At 15 min intervals during the simulation and either side of HT, players performed two single-leg-hops onto a force plate, to measure time to stabilisation (TTS), and three maximal isokinetic contractions at 120° s−1 for concentric (conQ) and eccentric knee extension (eccH), all using the dominant limb. There was a significant increase in vertical TTS during the HT interval in the CON trial compared with IAE (p<0.02), and in medial/lateral TTS for CON compared with IAE (p<0.01) and WBV (p<0.01). No significant interaction or main effects were observed for any of the strength variables (p>0.05). Active re-warm-up strategies improved early second half TTS compared with a passive HT, but there was no significant influence of HT strategy on muscular strength. Active re-warm-up strategies may be more beneficial for maintaining proprioception and thus preventing knee and ankle ligamentous sprains early second half than reducing the risk of muscular strains.]]