Daniel Le Gallais

The influence of prior cycling on biomechanical and cardiorespiratory response profiles during running in triathletes

Abstract The aim of the present study was to determine the effects of 40 km of cycling on the biomechanical and cardiorespiratory responses measured during the running segment of a classic triathlon, with particular emphasis on the time course of these responses. Seven male triathletes underwent four successive laboratory trials: (1) 40 km of cycling followed by a 10-km triathlon run (TR), (2) a 10-km control run (CR) at the same speed as TR, (3) an incremental treadmill test, and (4) an incremental cycle test. The following ventilatory data were collected every minute using an automated breath-by-breath system: pulmonary ventilation (V˙E, l · min−1), oxygen uptake (V˙O2, ml · min−1 · kg−1), carbon dioxide output (ml · min−1), respiratory equivalents for oxygen (V˙E/V˙O2) and carbon dioxide (V˙E/V˙CO2), respiratory exchange ratio (R) respiratory frequency (f, breaths · min−1), and tidal volume (ml). Heart rate (HR, beats · min−1) was monitored using a telemetric system. Biomechanical variables included stride length (SL) and stride frequency (SF) recorded on a video tape. The results showed that the following variables were significantly higher (analysis of variance, P < 0.05) for TR than for CR: V˙O2 [51.7 (3.4) vs 48.3 (3.9) ml · kg−1 · min−1, respectively], V˙E [100.4 (1.4) l · min−1 vs 84.4 (7.0) l · min−1], V˙E/V˙O2 [24.2 (2.6) vs 21.5 (2.7)] V˙E/V˙CO2 [25.2 (2.6) vs 22.4 (2.6)], f [55.8 (11.6) vs 49.0 (12.4) breaths · min−1] and HR [175 (7) vs 168 (9) beats · min−1]. Moreover, the time needed to reach steady-state was shorter for HR and V˙O2 (1 min and 2 min, respectively) and longer for V˙E (7 min). In contrast, the biomechanical parameters, i.e. SL and SF, remained unchanged throughout TR versus CR. We conclude that the first minutes of the run segment after cycling in an experimental triathlon were specific in terms of V˙O2 and cardiorespiratory variables, and nonspecific in terms of biomechanical variables.

Energy expenditure and cardiorespiratory responses at the transition between walking and running

AbstractWe investigated whether the spontaneous transition between walking and running during moving with increasing speed corresponds to the speed at which walking becomes less economical than running. Seven active male subjects [mean age, 23.7 (SEM 0.7) years, mean maximal oxygen uptake (

Factor analysis of quality of life, dyspnea, and physiologic variables in patients with chronic obstructive pulmonary disease before and after rehabilitation

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Fortuitous description of hemoglobin Hope in a high-level Tunisian athlete: molecular diagnosis and origin

), 57.5 (SEM 3.3) ml·kg −1·min −1, mean ventilatory threshold (VTh), 37.5 (SEM 3) ml·kg −1 ·min −1] participated in this study. Each subject performed four exercise tests separated by 1-week intervals: test 1,

The effect of exercise modality on respiratory muscle performance in triathletes.

\dot V{\text{O}}_{2\max }

Pulmonary responses during the cycle-run succession in elite and competitive triathletes.

and VTh were determined; test 2, the speed at which the transition between walking and running spontaneously occurs (ST) during increasing speed (increases of 0.5 km·h −1 every 4 min from 5 km·h −1) was determined; test 3, the subjects were constrained to walk for 4 min at ST, at ST ± 0.5 km·h −1 and at ST ± 1 km·h −1; and test 4, the subjects were constrained to run for 4 min at ST, at ST±0.5 km·-h −1 and at ST±1 km·h −1. During exercise, oxygen uptake (