M R Bonsignore1, G Morici, P Abate, S Romano, G Bonsignore. 1. Istituto di Scienze e Tecnologia dello Sport e dell'Attività Fisica, Consiglio Nazionale delle Ricerche, Palermo, Italy. romano@IFRPA.IFR.PA.CNR.IT
Abstract
PURPOSE: To assess whether entrainment of breathing (E) during exercise: 1) differed according to the test protocol in well-trained triathletes, and 2) improved ventilatory efficiency during exercise. METHODS: Eight triathletes performed three incremental tests until exhaustion: while cycling (CE), while running at increasing grade and constant speed (increasing GRADE) and while running at increasing speed and constant grade (increasing SPEED), respectively. E was evaluated as the percentage of breaths occurring at respiratory rates (F) corresponding to integer ratios of the exercise cycle rate. To assess whether E improved ventilatory efficiency, deltaVE/VO2 between nonentrained and entrained breaths was measured at each load. RESULTS: Mean E was higher in CE (57.2+/-21.9%) than in increasing GRADE (46.9+/-18.7%) and increasing SPEED (41.4+/-17.2%). E decreased at high loads in CE and increasing SPEED but not in increasing GRADE. In the group of subjects, E correlated with the degree of fitness (evaluated as VO2Tvent/VO2peak%) only during increasing GRADE. By multiple regression analysis on all data, minute ventilation correlated with CO2 production but not with the exercise cycle rate; however, either F or tidal volume correlated significantly with both these variables. VE/VO2 was lower in entrained than nonentrained breaths at each load in CE and increasing GRADE experiments, but the difference was small. CONCLUSIONS: In spite of some differences among protocols, triathletes showed significant E during incremental exercise tests. Spontaneous E appeared to slightly improve ventilatory efficiency during CE and increasing GRADE protocols.
PURPOSE: To assess whether entrainment of breathing (E) during exercise: 1) differed according to the test protocol in well-trained triathletes, and 2) improved ventilatory efficiency during exercise. METHODS: Eight triathletes performed three incremental tests until exhaustion: while cycling (CE), while running at increasing grade and constant speed (increasing GRADE) and while running at increasing speed and constant grade (increasing SPEED), respectively. E was evaluated as the percentage of breaths occurring at respiratory rates (F) corresponding to integer ratios of the exercise cycle rate. To assess whether E improved ventilatory efficiency, deltaVE/VO2 between nonentrained and entrained breaths was measured at each load. RESULTS: Mean E was higher in CE (57.2+/-21.9%) than in increasing GRADE (46.9+/-18.7%) and increasing SPEED (41.4+/-17.2%). E decreased at high loads in CE and increasing SPEED but not in increasing GRADE. In the group of subjects, E correlated with the degree of fitness (evaluated as VO2Tvent/VO2peak%) only during increasing GRADE. By multiple regression analysis on all data, minute ventilation correlated with CO2 production but not with the exercise cycle rate; however, either F or tidal volume correlated significantly with both these variables. VE/VO2 was lower in entrained than nonentrained breaths at each load in CE and increasing GRADE experiments, but the difference was small. CONCLUSIONS: In spite of some differences among protocols, triathletes showed significant E during incremental exercise tests. Spontaneous E appeared to slightly improve ventilatory efficiency during CE and increasing GRADE protocols.
Authors: François Cottin; Jean Slawinski; Philippe Lopes; Andry Van de Louw; Véronique Billat Journal: Eur J Appl Physiol Date: 2006-11-18 Impact factor: 3.078
Authors: Jennifer M Yentes; William Denton; Kaeli Samson; Kendra K Schmid; Casey Wiens; Stephen I Rennard Journal: Acta Physiol (Oxf) Date: 2018-12-07 Impact factor: 6.311