Effects of Blood Flow Restriction and Combined High-Intensity Strength Training on Lower Limb Muscle Strength and Recruitment Ability of Paralympic Alpine Skiers

Objective: To investigate the effects of blood flow restriction training(BFRT) with combined high-intensity strength training(COM) on the maximum muscle strength, muscle fiber recruitment capacity and rate of force development of lower limb muscles in Paralympic alpine skiers. Methods: Six athletes(3 males, 3 females) with an average age of 20.67±1.34 years from the standing class of the National Paralympic Alpine Skiing Team participated in this study. According to the MVC test results of the knee extensor, the relative weak side of lower limb was set as the experimental side(BFRT intervention side), and the other side was set as the control side(non-BFRT intervention side). Athletes completed a set of 75% 1 RM high-intensity strength training firstly,which includes machine knee extensor and flexor exercises, leg-press, hip adduction and abductor exercises, etc. Then, 4 sets of 30%1 RM leg press and machine knee extensor exercises were performed under the condition of experimental side pressure. The changes of maximal muscle strength, muscle fiber recruitment capacity and rate of force development before and after 2 weeks of the intervention were analyzed and compared. Results: 1) The maximum muscle strength of the experimental side was increased significantly(P=0.001); 2) The rate of force development was improved significantly in the experimental side(P=0.042); 3) There was no significant difference in RMS change rate of lateral vastus muscle and medial vastus muscle between the control side and the experimental side, the only difference was observed in rectus femoris muscle(P=0.02). Conclusions: The 2-week COM is more effective in improving the rate of force development and maximum strength of Paralympic alpine skiers' lower limb than that of traditional high-intensity strength training, and the COM can achieve training effects more quickly.