Study On Dynamic Changes Of EMG,Muscle Oxygen And RPE In Incremental Load Exercise

Purpose: By the test of increasing load exercise,this paper summarizes the dynamic changes of EMG,muscle oxygen and subjective physical sensation index,and studies the change relationship of EMG,muscle oxygen and subjective physical sensation index during incremental load exercise,in order to monitor the training process more comprehensively and accurately and better guide the training practice.Methods: Sixteen subjects were tested for incremental load of power bicycles.The initial power was set at 80 W,each stage was increased by 30 W,and each stage continued to exercise for 3 minutes.Until the subjects were repeatedly encouraged,the target power could not be maintained as the end of the test.The data of EMG,muscle oxygen,subjective physical sensation,heart rate and blood lactic acid were collected.The differences,correlations and interrelationships among EMG,muscle oxygen and subjective physical sensation indexes were studied by means of mathematical statistics and logical analysis.Results:1.The integral(IEMG)index and root mean square amplitude(RMS)index of rectus femoris,tibialis anterior muscle,biceps femoris and gastrocnemius muscle increased with the increase of exercise load,while the median frequency(MF)index and average power frequency(MDF)index did not increase with the increase of exercise load.2.When the subjects were doing incremental load exercise,the muscle oxygen saturation decreased with the increase of load.When the subjects exercised at lower load in 80W-140 W,muscle oxygen decreased at the beginning of each stage,and then remained relatively stable,and the change of muscle oxygen was small.With the increase of load,muscle oxygen decreased significantly from 140 W to 170 W.When the load is from 200 W to 230 W,the muscle oxygen fluctuates near a certain baseline,and the change range is small.3.In the increasing load exercise,the root mean square amplitude(RMS),muscle oxygen saturation,and time of the inflection point of the blood lactic acid of the subject all appeared in the fourth level.The subjective physical force perception(RPE)of the subject Also at the fourth level began to appear "labor".After statistical analysis,the root mean square amplitude(RMS),muscle oxygen saturation,and RPE of myoelectric indicators were significantly related to the inflection point of blood lactic acid(R greater than 0.6,except for the gastrocnemius muscle);the correlation between the left and right rectus femoris muscles and the lactic acid inflection point was significant.Sex is stronger than other muscles(R value is above 0.85).At the same time,it is found that the inflection point time of the root mean square amplitude is 653 s,and the inflection point time of muscle oxygen saturation is 711 s.The inflection point appears due to the blood lactate collection time.The test is over.It can be seen that the inflection time of the root mean square amplitude(RMS)in the EMG index is significantly earlier than the inflection time of the muscle oxygen saturation.4.During the increasing load exercise,the subject's EMG integral myoelectricity(IEMG)was significantly negatively related to myocardial oxygen(R =-0.634,P <0.01),and the integral myoelectricity(IEMG)was related to subjective physical feeling(RPE)is a significant positive correlation(R = 0.824 P <0.01);root mean square amplitude(RMS)is significantly negatively correlated with muscle oxygen(R =-0.579 P <0.01),and the root mean square amplitude(RMS)is related to subjective physical strength perception(RPE)was significantly positively correlated(R = 0.664 P <0.01);muscle oxygen was significantly negatively correlated with subjective physical exertion(RPE)(R =-0.675 P <0.01).Research conclusions:1.In increasing load exercise,IEMG and RMS in EMG index will significantly increase with the increase of load,which can better reflect the exercise load intensity of human body..2.The change of muscle oxygen saturation decreased with the increase of human exercise load,decreased less at lower load,decreased more at higher load,and decreased step by step in a certain range with the increase of load.3.There was a correlation between the inflection point time of RMS,muscle oxygen saturation,RPE and blood lactic acid during increasing load exercise,but the inflection point of RMS was more timely than that of muscle oxygen saturation.4.During the increasing load exercise,the EMG indexes IEMG,RMS and RPE were positively correlated,while the muscle oxygen saturation was negatively correlated with IEMG,RMS and RPE.5.Due to the influence of subjective physical sensation,the EMG and muscle oxygen indexes of different subjects change differently during exhaustion,so in the final stage of incremental load exercise,a single index can not accurately evaluate the condition of the subjects.joint monitoring of indicators of different systems is needed.