The pre-competition warm-up serves a number of important functions. Some of these include increases in body temperature, heart rate and oxygen consumption, increased muscle contraction speed, increased synovial fluid and joint mobility. These physiological responses can help increase performance and potentially reduce injury risk. The timing of the warm-up before a match can therefore play an important role in team performance early on. Warming up too early with excess wait time before game time may result in a reversal in warm-up effects. While most coaches are aware of this and plan accordingly, the pre-game period is not the only time players should be warming up. For example, post-halftime and before substituting for cold players are both important times where players would benefit from warming up.
A new case study published in the journal “Sports” investigated the physiological responses to warming up and subsequent reversal of these responses from being sidelined. Two high level adult male basketball players volunteer for the study. Before and after a 20 minute warm up and again throughout the first half of a competitive basketball match, performance measures (countermovement jump) and physiological measures (heart rate, core temperature and skin temperature) were obtained. The warm-up was comprised of jogging, dynamic stretches and basketball-specific drills. The researchers wanted to determine if substitute players were physiologically ready to perform after being sidelined for about one half of play.
The results showed that compared to pre-warm-up, post-warm-up countermovement jump height improved by about 7%. After being sidelined for the half, countermovement jump heights dropped between 12 and 15%, nearly 7% below baseline values. Core temperature increased by roughly 1 degree following the warm-up, then progressively reduced (~0.5 degree) throughout the half, though remained above baseline. Skin temperatures peaked during the warm-up and progressively reduced towards baseline from passive rest during the half. Heart rate peaked at 170 – 180 beats per minute during the first 10-12 minutes of warming up. Within 6 minutes of the half, heart rate dropped to <100 beats per minute and continued to progressively decrease towards baseline thereafter. The authors conclude that key performance indicators are reduced and physiological responses to warming up are reversed in substitute players who passively wait on the sidelines to be called in. Thus, having players warm up on the sideline before being sent in may improve performance.
Crowther, R.G., et al. Influence of Rest on Players’ Performance and Physiological Responses during Basketball Play. Sports 2017, 5(2), 27.