Effect of Pilates Method on muscular trunk endurance and hamstring extensibility in adolescents during twelve weeks training and detraining

Background: Thoracic hyperkyphosis and lumbar hyperlordosis have been associated with low values of flexibility in the hamstring muscle and endurance of the trunk musculature. These are areas that are worked using the Pilates Method (PM), however, there are only two studies that assess its effect on these variables in adolescence, and none that measure the retention time of the acquired improvements. The main objective of this research was to assess the effect of 10 min of adapted exercise program from PM in a Physical Education class (PE) for 12 weeks, on trunk muscle endurance and hamstring flexibility, and to evaluate the retention of resulting changes. Methods: The sample consisted of 441 adolescents (age = 13.9 +/- 1.3 years). The experimental group (EG) performed two weekly 10-min sessions of PM for 12 weeks. The control group (CG) performed its usual sessions of PE. The endurance of the trunk flexor muscles and trunk extensor muscles, toe touch test (TT), bench trunk curl test (BTC) and the Biering-Sorensen test (SOR), were used to evaluate hamstring flexibility, before application of the program, at the end, 12 weeks later. Results: A significant improvement was found in the EG for all variables analyzed, with an average improvement of 9.37 repetitions in the BTC test, 19.4 s in the SOR test and 2.75 in the TT test. The CG did not show significant changes. The EG's improvements were retained 12 weeks later, except in the SOR test. Conclusion: The inclusion of 10 min of adapted exercise program from PM in PE classes, for two weekly sessions over 12 weeks, produces improvements in trunk muscle endurance and hamstring flexibility, and these gains are retained in the flexor and hamstring muscles 12 weeks later. (C) 2020 Elsevier Ltd. All rights reserved.