Monitoring Changes Over a Training Macrocycle in Regional Age-Group Swimmers.

Our aim was to analyze physiological, kinematical and performance changes induced by swimming training in regional age-group athletes. Subjects (15.7 ± 2.2 years old) performed a 4 x 50-m front-crawl test at maximal velocity (10 s rest interval) in weeks 2, 4, 9 and 12 of a 15-week macrocycle. Descriptive statistics were used and the percentage of change and smallest worthwhile change (moderate, 0.6-1.2, and large, > 1.2) were measured. Lactate concentration in the third, seventh and twelfth minute of recovery decreased significantly between weeks 2-9 (14.1, 15.7 and 17.6%) and increased between weeks 9-12 (18.2, 18.6 and 19.8%), with the HR presenting only trivial variations during the training period. Stroke length showed a large decrease in the first 50-m trial between weeks 4-9 (6.2%) and a large increase between weeks 9-12 (3.1%). The stroke rate (in all 50-m trials) increased significantly between weeks 4-9 (3- 7%) and the stroke index had a moderate to large increase in the first and third 50-m trial (3.6 and 7.1%, respectively) between weeks 9-12. The overall time decreased by 1.1% between weeks 2-12, being more evident after week 4. We concluded that physiological, kinematical and performance variables were affected by the period of training in regional age-group swimmers.