Effect Of Respiratory Muscle Training On Cardiopulmonary Function And Exercise Performance In Healthy Students

Objective:①To investigate the effect of 4-week inspiratory and expiratory muscle training on respiratory muscle strength and endurance in healthy people,and to evaluate the effect of these changes whether lead to conventional lung ventilation and cardiopulmonary exercise testing changes in lung function of each indicator.②To determined 4 weeks inspiratory muscles and expiratory muscle training whether enhance exercise performance and effect the value of V O2peak determinged with the subjective feeling criterion ,while compare the effect of inspiratory muscle training and expiratory muscle training.Method: 1. Subjects: 27 female health people who were students attending the shandong normal university volunteered to take part in this investigation. Each subject's level of physical activity was assesses by physical activity index questionnaire and PARQ&YOU questionnaire.Subjects were randomly divided into IMT group (n = 11), EMT group (n = 10) and the control group (n = 6). All subjects were nonsmokers and had no evidence of pulmonary pathology(eg. asthma)or any known metaboluc or endocrine disorder.Subjects were written consent prior to the study.2.Respiratory muscle training:Using the specially respiratory muscle training device which designed in our laboratory. The training group(IMTgroup and EMT group)completed an 4-week program of IMT set at 80% of maximal effort (MIP or MEP).The IMT group subject took a deep full inspiration from FRC to 80%MIP for 5 seconds and the EMT group comllete exhalation from TLC to 80%MEP for 5 seconds The subect then removed the mouthpiece,breathed normally,and waited for the next time cycle.30 times/30 minutes/day,5 days/week,a total of 20 training periods.At each traing session, the subjects were retested to determine their current value for 80% of maximal effort.The control group did not participate in any from of training.3.Experimental design:The dynamic changes of respiratory muscle(inspiratory muscle and expiratory muscle) strength and endurance,lung function,anaerobic threshold,V O2peak values and exercise performance had been measured during the four weeks of IMT and EMT. Determined the changes of anaerobic capacity and body composition before and after RMT(IMTand EMT), and inspiratory muscle training and expiratory muscle training effect were compared.4.Measurment protocols:①Subjects body composition were determined using the Vivente Body Composition Analyzer which was made in Korea.②Using the specially respiratory muscle training device which designed in our laboratory to measured maximal inspirtatory pressure and maximalexpirtatory pressure.③Using the MasterScreen CPX ergospirometry testing device evaluate subjects conventional lung ventilation,Sports lung ventilation and V O2peak value.④A progressive incremental exercise test was performed on ergolin 150P electronically bicycle ergometer to measure subject achieved maximum load and exercise time.⑤Using the Monark Ergomedic 894E bicycle ergometer to measure anaerobic exercise performance.Statistical analysis: Statistical analysis was conducted using SPSS 15.0 for windows with descriptive statistics and inferential statistics. Including Independent-samples T test,Paired–sample T test and Repeated messures.All data are expressed as Mean X±SD. P﹤0.05 and P﹤0.01 were accepted as being statistically significant respectively.Results:①Following 4 weeks respiratory muscle training, IMT group of maximum inspiratory pressure (MIP) from 27.09±4.85cmH2O to 50.00±2.97cmH2O, increase of 85%,(P<0.01). EMT group MIP increased from 28.60 ±3.78cmH2O 39.20±4.64cmH2O, increase of 31%, (P<0.01). control group MIP from 30.00±4.73cmH2O to 29.33±4.32cmH2O, has not change significantly, (P﹥0.05). EMTgroup, maximal expiratory pressure (MEP) from 23.40±4.22cmH2O to 44.20±3.05cmH2O, (P<0.01).IMT group MEP was increased, from 26.91±5.82cmH2O to 37.64±5.12cmH2O, (P<0.01). Control group, MEP from 28.33±5.28cmH2O to 28.00±7.27cmH2O, no significant changes, (P﹥0.05). compared to the fourth week after two weeks recovery have no significant change in IMT and EMT.②Maximum inspiratory pressure and maximal expiratory pressure duration in the three groups are no significant change after 4 weeks IMT and EMT.( P﹥0.05 ) .③After 4 weeks of inspiratory muscle training, VT(56%),MV(60%),VC(11%),FEV1(11%),FVC(10%),PEF(21%),PIF(38.50%)andMVV(24%) have increased significantly(P﹤0.05 or P﹤0.01).there was no significant changein FEV1/FVC. After two weeks of recovery, showed a further improvement in PEF. Follow 4 weeks of expiratory muscle training, VT(50%),MV(44%),VC(13.9%),FEV1(13.9%),FVC(13%),PEF(25%),PIF(33.5%) and MVV(21%) increased significantly (P﹤0.05 or P﹤0.01), there was no significant change in FEV1/FVC. During the two weeks of recovery, VCmax, FVC, PIF showed a further improvement.Conventional lung ventilation in control group did not significantly change(P﹥0.05).④At anaerobic threshold(AT) phase ,IMT group had a small increase but no significant changes in Load, from 75.00±19.36W to 86.64±17.19W (P = 0.067). EMT group also have a small increase in Load, from 73.75±14.96W to 85.00±21.08W (P = 0.068). there was no change in control group from 62.50±7.91 to 58.33±12.91W. At AT phasem,IMT group and EMT group VO2/VO2max value had significant changes in the second, third or fouth week after training(P﹤0.05 or P﹤0.01). No increase in VO2/VO2max,Load was observed in the control group.⑤Maximal power output (Loadmax) increased from 112.5±12.50W 129.55±15.08W,by increase 15%. From the second week there was a significant difference(P﹤0.05 or P﹤0.01). Time to exhausion (Tmax) from 15.95±1.57min to 17.24±1.47min, by increase 8%. From the third week there were significant increase(P﹤0.05 or P﹤0.01). EMTgroup Loadmax from 113.75±17.13W to 122.50±18.45W, only in the fourth week, there were significant increase,(P﹤0.05 or P﹤0.01). Tmax from 15.66±1.62min to 16.85±1.62min, starting from the third week of significant changes. The RPE was no significant change. Threr was no significant in RPE of both IMTand EMT group(P﹥0.05).In control group LOADmax, Tmax, RPE values was no significant change after four weeks ( P﹥0.05).⑥IMTgroup V O2peak from 21.23±3.81ml/min/kg to 28.66±2.83 ml/min/kg, by increase 35%(P﹤0.05 or P﹤0.01). During the two weeks of recovery up to 29.25±3.66 ml/min/kg. VEmax increased from 40.05±10.00L/min to 59.73±13.36L/min, two weeks after recovery of 60.91±11.41L/min, by increase of 49%(P﹤0.05 or P﹤0.01).V O2peak from 20.48±3.21ml/min/kg to 26.97±5.84 ml/min/kg, an increase of 32%(P﹤0.05 or P﹤0.01). Two weeks after the resumption of 27.55±4.45 ml.min-1.kg weight -1,in EMTgroup.VEmax increased from 35.50±5.21L/min 54.60±13.33L/min, an increase of 53%(P﹤0.05 or P﹤0.01). During the two weeks of recovery VEmax to 57.70±10.26L/min. The PETCO2max no significant differenceboth in IMT and EMT.Control group showed no significant difference in V O2peak,VEmax,(P﹥0.05),but PETCO2max significant increase(P﹤0.05 or P﹤0.01).⑦There was no significant change in anaerobic perfoumance either in the training group(IMT and EMTgroup) or control group,(P﹥0.05).Conclusions: The four weeks of inspiratory muscle training and expiratory muscle training can significantly improve the inspiratory muscles and expiratory muscle strength and endurance,so conventional lung ventilation and Sports lung ventilation were significantly improved.aslo can significantly increase the value of V O2peak,as well as increasing exercise performance of GXT. Compared to the effect of RMT is IMT better than EMT.Suggestion: Further compare to different intensity of the MIP,MEP training on different populations(age, sex, sports event, training frequency) of the different effects on exercise performance in order to better target used in sports practice.