The effect of video-feedback on the learning of the tennis service by intermediate players

Effects of video-feedback on improvement of the tennis service were investigated in subjects having at least 2 years of playing experience in tennis. The experiment was carried out in an indoor tennis hall under normal training conditions. Subjects were randomly divided into three groups: a video-feedback training (VFT) group, a traditional training (TT) group and a control group, each consisting of 22 subjects. While the subjects of the control group received no training at all, subjects in both the VFT and TT groups were trained twice weekly during 5 consecutive weeks. Each training session lasted 40 min, of which 30 min was spent on actual practice in training of the service. The remaining 10 min was spent on watching, analysing and discussing video recordings of either their own service performed during the training session (VFT group), or ground strokes and volleys of top level players (TT group). Both the VFT and TT group showed significantly greater improvements in both achievement scores and form (technique) scores than did the control group. No differences, however, could be demonstrated between the VFT and TT group, indicating that the subjects of the former group did not benefit from the video-feedback they received. While form scores correlated significantly (P less than 0.001) with the velocity of the served ball, no such relation between form scores and spatial accuracy was apparent.     

Sensitive ages for physical fitness development

Physical fitness testing in Singapore is mandatory from age 9 years old till 18 years old in schools. Time and effort are spent annually in training for these tests as schools are ranked according to the test results and pupil obesity rate. There are natural rhythms and tempos for the development of physical capabilities but these remain unexplained in the Singaporean context. Identification of these ＂sensitive time periods＂ for fitness development will help PE teachers be more realistic about young people＇ s physical fitness and allow for a more balanced approach in the conduct of PE in schools.