The effect of acute heat exposure on the determination of exercise thresholds from ramp and step incremental exercise.

Autor: Bourgois G; Department of Movement and Sports Sciences, Ghent University, Watersportlaan 2, 9000, Ghent, Belgium.; Univ. Lille, Univ. Artois, Univ. Littoral Côte d'Opale, ULR 7369-URePSSS-Unité de Recherche Pluridisciplinaire Sport Santé Société, F-59000, Lille, France., Colosio AL; Department of Movement and Sports Sciences, Ghent University, Watersportlaan 2, 9000, Ghent, Belgium., Caen K; Department of Movement and Sports Sciences, Ghent University, Watersportlaan 2, 9000, Ghent, Belgium.; Centre of Sports Medicine, Ghent University Hospital, Ghent, Belgium., Bourgois JG; Department of Movement and Sports Sciences, Ghent University, Watersportlaan 2, 9000, Ghent, Belgium.; Centre of Sports Medicine, Ghent University Hospital, Ghent, Belgium., Mucci P; Univ. Lille, Univ. Artois, Univ. Littoral Côte d'Opale, ULR 7369-URePSSS-Unité de Recherche Pluridisciplinaire Sport Santé Société, F-59000, Lille, France., Boone J; Department of Movement and Sports Sciences, Ghent University, Watersportlaan 2, 9000, Ghent, Belgium. jan.boone@ugent.be.; Centre of Sports Medicine, Ghent University Hospital, Ghent, Belgium. jan.boone@ugent.be.
Jazyk: angličtina
Zdroj: European journal of applied physiology [Eur J Appl Physiol] 2023 Apr; Vol. 123 (4), pp. 847-856. Date of Electronic Publication: 2022 Dec 12.
DOI: 10.1007/s00421-022-05106-y
Abstrakt: Purpose: The aim of this study was to examine how respiratory (RT) and lactate thresholds (LT) are affected by acute heat exposure in the two most commonly used incremental exercise test protocols (RAMP and STEP) for functional evaluation of aerobic fitness, exercise prescription and monitoring training intensities.
Methods: Eleven physically active male participants performed four incremental exercise tests, two RAMP (30 W·min -1 ) and two STEP (40 W·3 min -1 ), both in 18 °C (TEMP) and 36 °C (HOT) with 40% relative humidity to determine 2 RT and 16 LT, respectively. Distinction was made within LT, taking into account the individual lactate kinetics (LT IND ) and fixed value lactate concentrations (LT FIX ).
Results: A decrease in mean power output (PO) was observed in HOT at LT (-6.2 ± 1.9%), more specific LT IND (-5.4 ± 1.4%) and LT FIX (-7.5 ± 2.4%), compared to TEMP, however not at RT (-1.0 ± 2.7%). The individual PO difference in HOT compared to TEMP over all threshold methods ranged from -53 W to +26 W. Mean heart rate (HR) did not differ in LT, while it was increased at RT in HOT (+10 ± 8 bpm).
Conclusion: This study showed that exercise thresholds were affected when ambient air temperature was increased. However, a considerable degree of variability in the sensitivity of the different threshold concepts to acute heat exposure was found and a large individual variation was noticed. Test design and procedures should be taken into account when interpreting exercise test outcomes.
(© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)
Databáze: MEDLINE
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