Changes in muscle strength and speed of an unloaded movement after various training programmes

Summary

The effect of three different training programmes on the maximal speed of an unloaded movement (a karate punch) was studied. Three movement variables were selected: maximal speed of the hand (ν_h,max), maximal speed of the shoulder (ν_s,max) and elbow extension speed$\left( {\dot \Theta _E } \right)$ simultaneous with ν_h,max. The programmes were: training group 1 (TG 1,n = 8) -karate students, dynamic heavy progressive resistance exercise (incline situp and incline bench press) + punch bag exercise; training group 2 (TG 2,n = 8) - karate students, punch bag training; training group 3 (TG 3,n = 5) - no karate experience, dynamic heavy progressive resistance exercise (as in TG 1). The movement variables were calculated from chrono-cyclo photographic recordings of the punches (100 Hz). The level of significance was set at 5%. Sixteen weeks of training gave the following results: significant increases in dynamic strength in all the training groups (14%–53%). In TG 1 the ν_{h, max} increased significantly from 8.49 m·s⁻¹, SD 1.19 to 9.35 m·s⁻¹, SD 1.29 (10%); ν_s,max increased significantly in TG 1 by 32% (2.18 m·s⁻¹, SD 0.56 to 2.87 m·s⁻¹, SD 0.98) and in TG 2 by 14% (2.40 m·s⁻¹, SD 0.61 to 2.74 m·s⁻¹, SD 0.52), and in TG 3$\left( {\dot \Theta _E } \right)$ at ν_{h, max} increased significantly from 28.6 rad · s⁻¹, SD 4.3 to 32.2 rad·s⁻¹, SD 4.5 (13%). No significant relationships between the changes in maximal muscle strength and the changes in movement speed were found. The significant changes in ν_h and ν_s among the karate trained subjects (TG 1 and TG 2) are ascribed to a change in the kinematics of the segmental motions induced by the karate training, to a movement pattern that takes advantage of the potentiating effect of a stretch-shortening cycle on muscle power output in flexor muscles of the shoulder and the extensor muscles of the elbow.