The Effects of Varying Intensity Swimming and Kick Practice During a Warm Up on 200 m Freestyle Performance in Age Group Competitive Swimmers

摘要

The aim of this study was to compare the effects of warm up at high (set at 90% of Maximal Aerobic Speed) and low (set at 70% of Maximal Aerobic Speed) intensity swimming, along with the inclusion and exclusion of isolated kick practice on 200 m freestyle swimming performance in Age Group swimmers (defined by British swimming as 11-14 years). This study was approved by the University of Gloucestershire’s Research Ethics Committee. Seventeen competitive Age Group swimmers (n = 9 males, age 12 ± 1.22yrs, stature 1.58 ± 0.10m, mass 49.3 ± 9.75kg; n = 8 females, age 12 ± 0.99yrs, stature 1.58 ± 0.09m, mass 48.6 ± 7.79kg) performed four 200 m freestyle time trials on separate days after a specific warm up design, either low intensity without kick, low intensity with kick, high intensity without kick or high intensity with kick. All warm up protocols included five minutes land warm up activities focused on mobilisation and activation followed by two minutes of easy front crawl swimming. The warm up protocols then consisted of six minutes of either low intensity or high intensity front crawl swimming and two minutes of isolated front crawl kick; respective to the warm up design. All warm up protocols finished with two minutes of easy front crawl swimming and a five minute passive recovery period. The key findings of this study is that there was no statistically significant change in 200 m freestyle time trial results of Age Group swimmers in respect of total time or split times when manipulating intensity and kick variables during the warm up. The two-way repeat measures ANOVA test showed that there was no significant interaction effect between Intensity*Kick (P=0.171 - ETA2 0.114), or main effect for Intensity (P=0.131 - ETA2 0.137) and main effect for Kick (P value 0.692 - ETA2 0.010). These results suggest that high intensity priming exercises associated with a speeding of V ̇O2 kinetics has not improved performance which is in contrast to studies on 800 m running (Bailey et al. 2009). The results also suggest that swimming at a low intensity is sufficient enough to stimulate blood flow to the legs and increasing muscular temperature without isolated kick practices. This suggests that coaches may be correct in their current warm up protocols focusing on preparing for technical and tactical aspects of the event rather than physiological preparedness. Through examining the pacing strategies employed by 200 m freestyle swimmers, it would suggest that they do not reach their maximal workload until the final quarter of the event. This delay in maximal effort may allow the aerobic metabolism time to adjust to the exercise intensity thus diminishing the need for priming and a speeding of V ̇O2 kinetics.