PHYSIOLOGICAL AREA   

Medicina dello Sport 2020 September;73(3):405-17

DOI: 10.23736/S0025-7826.20.03729-1

Copyright © 2020 EDIZIONI MINERVA MEDICA

language: English, Italian

Relationships between lung volume and respiratory muscle performance in triathletes

Alain BOUSSANA ^{1, 2} ✉, Olivier GALY ³, Daniel LE GALLAIS ⁴, Olivier HUE ²

¹ Adaptation Laboratory, Health, Expertise and Optimization of Sport Performances, High Institute of Physical and Sports Education (ISEPS), Marien Ngouabi University, Brazzaville, Congo; ² ACTES Laboratory, UFR STAPS, University of the French West Indies and Guiana, Pointe à Pitre, France; ³ Interdisciplinary Laboratory for Research and Education, University of New Caledonia, New Caledonia, France; ⁴ Laboratory of Sport Performances and Health, Faculty of Sport Sciences, UPRES EA 2991, Montpellier, France

BACKGROUND: Increase or decrease in lung volumes has been reported following short bouts of high-intensity exercise, and prolonged, moderate intensity exercise, and attributable to the decrease on respiratory muscle strength and endurance. This study investigated whether a change in initial lung volume influences the decrease in respiratory muscle performance in triathletes during a cycle-run succession (C-R).
METHODS: Thirteen male triathletes performed a two-trial protocol: 1) an incremental cycle exercise to assess maximal oxygen uptake (V̇O2max); and 2) combinations of cycling (20 min) and running (20 min) performed at 75% of V̇O2max. Spirometry test was performed at rest and immediately after cycle-run succession. Respiratory muscle force was assessed by measuring maximal expiratory (PEmax) and inspiratory (PImax) pressures before and 10 min after C-R. Lastly, respiratory muscle endurance was measured 1 day before and 30 min after C-R.
RESULTS: The results showed a significant decrease in forced vital capacity (FVC) and significant increases in residual volume (RV) and in functional residual capacity (FRC) (P<0.05). Maximal inspiratory pressure (134.92±5.0 cmH2O versus 127.69±7.2 cmH2O) and endurance time limit (5.38±0.4 min versus 3.45±0.4 min) were decreased post-cycle-run succession compared with pre-cycle-run succession (P<0.001). Interestingly, we found a significant correlation between pre- versus post-cycle-run succession forced vital capacity and residual volume (r=0.60, P<0.02).
CONCLUSIONS: The cycle-run succession induced respiratory muscle fatigue. However, the lack of correlation suggests that the decrease in the respiratory muscles’ performance is still not responsible for changes in lung volumes, but could be explained by other phenomena.

KEY WORDS: Muscle strength; Muscle fatigue; Lung volume measurements