Effects Of Acute Hypoxic Resistance Training On Lower Extiemity Muscle Recruitment And PAP

Obejective:To explore the mechanism of resistance training in hypoxia on neuromuscular recruitment and PAP by observing the effects of acute high-intensity resistance training in normoxia,acute high-intensity resistance training in hypoxia and low-intensity resistance training in hypoxia on PAP and muscle recruitment.Methods: Study one :12 subjects completed the training of high-intensity resistance training in normoxia(90% 1 RM,3 / group,a total of three groups,intermittent 90 sec),high-intensity resistance training in hypoxia(altitude at 4000 m,90% 1 RM,3 / group,a total of three groups,intermittent 90 sec)and low-intensity resistance training in hypoxia(45% 1 rm,6/group,a total of three groups,intermittent 90 sec),respectively in each weekly interval.The height of CMJ and i EMG in maximum isometric contraction were measured before and after the training.Study two: 7 subjects were trained same as the protocol described in study one.The height of CMJ and knee extension torque in maximum isometric contraction were measured before and after the training,as well as the EMG of the rectus femoris,lateral femoral and medial femoral muscle in both legs.RFD and EMD were analyzed.Results: study one: All subjects had PAP in the test after the training of high-intensity resistance training in normoxia,high-intensity resistance training in hypoxia and low-intensity resistance training in hypoxia.The height of CMJ after low-intensity resistance training in hypoxia(56.1±4.4cm,p<0.05)was significant higher both than the height of CMJ after high-intensity resistance training in hypoxia(52.6±4.8cm,p<0.05)and high-intensity resistance training in normoxia(53.1±4.8cm,p<0.05).Eight minutes after the trainings,the height of CMJ in low-intensity resistance training in hypoxia group(58.4±5.5cm,p<0.05)was significant higher than high-intensity resistance training in normoxia group(55.9±5.8cm,p<0.05).PAP only appeared after high-intensity resistance training in normoxia for 4 minutes.However,PAP not only appeared after high-intensity resistance training in hypoxia,but also lasted for 8 minutes and disappeared at the 12 th minute of the training.The muscle recruitment after low-intensity resistance training in hypoxia for 4 minutes(2983.2±1489.3,p<0.05)and 12 minutes(3447.8±1894.7,p<0.05)were significant higher than the muscle recruitment after high-intensity resistance training in hypoxia for 4 minutes(1959.7±445.7,p<0.05)and 12 minutes(2131.8±761.7,p<0.05),respectively.Study two: As showed in the results of isometric strength test,PAP only appeared after low-intensity resistance training in hypoxia for 4 minutes,and lasted more than 12 minutes.The EMD value after low-intensity resistance training in hypoxia for 12 minutes(73.14±4.15 ms,p<0.05)was significant lower than the EMD value after high-intensity resistance training in normoxia for 12 minutes(98.14±10.19 ms,p<0.05).Conclusion: PAP can be generated after high-intensity resistance training in normoxia,high-intensity resistance training in hypoxia,low-intensity resistance training in hypoxia.And the low-intensity resistance training in hypoxia works best.