Examining warm-up decrement as a function of interpolated open and closed motor tasks: implications for practice strategies.

Warm-up decrement (WUD) is a loss in the level of physical performance following rest and prior to subsequent trials. The activity-set hypothesis is one of several explanations for this phenomenon. The purposes of this study were to field test the efficacy of the activity-set hypothesis and explore the effectiveness of performing closed and open interpolated tasks in reducing WUD. The criterion task was hitting tennis ground strokes in response to a ball tossing machine, an open skill. Elite players (n = 20) from a tennis club in New South Wales, Australia, practised either a closed or open task, or rested, prior to resuming the first post-rest trial, using a repeated-measures design. The results yielded partial support of the activity-set hypothesis. Although the closed interpolated task markedly reduced WUD, open skill practice solicited better post-rest performance. Warm-up decrement was clearly evident under the rest condition. Furthermore, post-rest scores were statistically superior for the open skill condition as compared to practising a closed interpolated task, at least for the first two post-rest trials (trials 21 and 22). The implications for these results in reducing WUD are explored within the frameworks of task classification systems and schema theory.