A field test of the activity-set hypothesis for warm-up decrement in an open skill.

To determine the relative effectiveness of different warm-up activities in eliminating postrest warm-up decrement (WUD), 65 highly skilled tennis players performed 60 forehand and 60 backhand groundstrokes, rested for either 5 or 15 min, engaged in one of five interpolated activities (additional rest, running in place, imagery, practice swings, or air dribbling), and then performed 12 additional forehands and backhands. An analysis of differences between prerest and postrest arousal measures (heart rate, positive cognitive arousal, and negative cognitive arousal) revealed that all of the interpolated activities except additional rest restored arousal to levels near those found at the end of prerest trials. Postrest WUD was also eliminated by practice swings and air dribbling and, to a slightly lesser extent, by running in place. We concluded that an effective warm-up for open skills such as the tennis groundstroke should include some form of overt physical activity that direct the attention of the performer to task-relevant cues.