【論文摘要】The Relationship Between Maximal Oxygen Consumption and Inspiratory Muscle Activation During Threshold Loaded Breathing in Healthy Adults

【論文摘要】健康成年人最大攝氧量與執行吸氣肌訓練時之吸氣肌活化模式之關係

黃維羽(Wei-Yu Huang) ； 何珈萱(Kar-Xuen Hoh) ； 王儷穎(Li-Ying Wang)

《物理治療》 46卷2期 (2021/06) Pp. 120-121

https://doi.org/10.6215/FJPT.202106.P08

摘要

Background and Purpose: The respiratory system has been described as a limiting factor in aerobic performance in healthy and diseased populations. Inspiratory muscle is under challenges when the ventilation demand is high. Previous studies on whether inspiratory muscle training (IMT) could improve maximal oxygen uptake (VO2max) were inconclusive. In this study, we aimed to examine whether respiratory muscle performance during cardiopulmonary exercise test (CPET) correlated with inspiratory muscle activation strategy during threshold loaded breathing. Methods: Ten healthy adults (mean ± standard deviation [SD] age was 20.9 ± 0.9 years old; 6 male and 4 female) without a history of respiratory-related diseases were recruited for this study. The subjects underwent a CPET and loaded breathing test on 2 separate days, at least 7 days apart. Respiratory performance was measured during CPET. The intensity for threshold loaded breathing test was set at 30% maximal inspiratory pressure (MIP). Surface electromyography (EMG) was used to measure diaphragm and sternocleidomastoid (SCM) activation during threshold loaded breathing test. Pearson correlation was used to examine the relationship between the respiratory performance parameters of CPET and inspiratory muscle activation during threshold loaded breathing test. Results: The mean (± SD) of VO2max and MIP were 36.3 (± 7.1) mL/kg/min and 109.8 (± 23.2) cmH_2O, respectively. The only respiratory performance parameter found to correlate with muscle activation during threshold loaded breathing test was respiratory rate (RR). Pearson correlation analysis showed that RR had significant negative correlations with changes of diaphragm (r = -0.86, p = 0.03) and SCM (r = -0.67, p = 0.03) activation from quiet breathing. Conclusion: Respiratory rate achieved during CPET correlated significantly and negatively with inspiratory muscle activation during threshold loaded test. Clinical Relevance: Healthy individuals might use different strategy in response to increases in ventilation demand during CPET and IMT. This phenomenon might partially explain the mix-results of IMT on VO2max improvement.