Effects of Sprint-Interval and Endurance Respiratory Muscle Training Regimens

Introduction Recently a novel, time-saving respiratory muscle sprint-interval training (RMSIT) was developed. To test the extent to which RMSIT improves respiratory muscle performance compared to a conventional respiratory muscle endurance training (RMET), a novel incremental respiratory muscle test (IncRMT), loading inspiratory and expiratory muscles, was designed to assess performance changes associated with respiratory muscle training (RMT). Methods Healthy, moderately trained males and females (age: 26 ± 5years, V[Combining Dot Above]O2peak: 47 ± 12 ml·min-1·kg-1) were randomized and balanced to 3 groups (RMSIT 5m/5f; RMET 6m/6f; PLAT 5m/6f). Lung function, respiratory muscle strength and IncRMT performance were tested before and after one month of RMT. During the IncRMT, muscle activity and muscle deoxygenation were assessed via surface electromyography and near-infrared spectroscopy of sternocleidomastoid (STERNO), intercostal (INTER) and abdominal (ABDO) muscles. Results Two-way ANOVA revealed a main effect of training for increased maximal voluntary ventilation (P = 0.001) and maximal inspiratory pressure (P = 0.017). Both RMT groups increased work of breathing during training sessions to the same extent (RMSIT: +17.4 ± 8.9kJ, RMET: +26.2 ± 16.1kJ; P = 0.143) with a larger increase in average mouth pressure in RMSIT (RMSIT: +20.0 ± 15.0cmH2O, RMET: +3.3 ± 1.5cmH2O; P = 0.001). After training, IncRMT duration increased in both RMT groups compared to PLAT (RMSIT: +5.6 ± 2.1min; P = 0.0006 vs. PLAT; RMET: +3.8 ± 4.2min; P = 0.020 vs. PLAT). At similar work, only INTER activity during inspiration increased following RMET. Higher performance following RMSIT was associated with higher activity in STERNO and ABDO, while following RMET, STERNO, INTER and ABDO showed higher activity. Conclusion One month of RMSIT and RMET show similar improvements in respiratory muscle performance despite different duration of training sessions. Also, muscular adaptations might differ. Corresponding Author: Prof. Christina M. Spengler, PhD, MD, ETH Zurich, Exercise Physiology Lab, Winterthurerstrasse 190, 8057 Zurich, +41 44 635 50 07. christina.spengler@hest.ethz.ch The partial contribution by CTI (grant no. 15650.1 PFLS-LS) includes a combination of two funding sources, funding provided by the federal granting agency and funding provided by an industrial partner (idiag AG, Switzerland). Neither was involved in any part of the study itself. Results of the present study do not constitute endorsement by ACSM. Results are presented clearly, honestly, and without fabrication, falsification, or inappropriate data manipulation. Accepted for Publication: 6 September 2018 © 2018 American College of Sports Medicine

from Sports Medicine via xlomafota13 on Inoreader https://ift.tt/2Nf3uAk
via IFTTT