Author Identifier
Jason R. Boynton: https://orcid.org/0000-0003-2848-0694
Chris R. Abbiss: https://orcid.org/0000-0003-3940-5542
Document Type
Journal Article
Publication Title
Journal of Strength and Conditioning Research
Volume
39
Issue
3
First Page
e485
Last Page
e495
Publisher
National Strength and Conditioning Association
School
School of Medical and Health Sciences
Funders
Australian Government Research Training Program Scholarship
Abstract
This study investigated cardiopulmonary responses in hot and cool high-intensity interval training (HIIT) and the subsequent effects on time-trial (TT) performance and physiological responses in temperate conditions. Twenty trained cyclists were separated into 2 groups and completed a 4-week HIIT intervention (8 sessions, 5 × 4 minute) at an environmental temperature (TA) of either 13° C (HIIT13) or 35° C (HIIT35). Cardiorespiratory data (e.g., heart rate [HR] and time above 90% Vo2max [T > 90% Vo2max]) were assessed for the first and last interval sessions. Infjects completed 20 km TTs in temperate conditions (22° C) before (TT1) and after (TT2) HIIT training, during which power output, HR, and thermoregulatory measures were recorded. T > 90% Vo2max was greater in HIIT13 (875 ± 295 seconds; p = 0.007), compared with HIIT35 (420 ± 395 seconds). Average power output during the TT increased from TT1 to TT2 in both groups (HIIT13 p = 0.023, 3.3 ± 3.4%; HIIT35 p = 0.003, 7.3 ± 6.3%) but with no significant interactions or differences between groups (p = 0.115; p = 0.421, respectively). Within-infject increases for HR and core temperature were observed during TT2 for HIIT13 (2.7 ± 2.1%, 0.5 ± 0.6%) but not HIIT35 (1.5 ± 4.9%, 0.0 ± 0.7%). After 4 weeks of HIIT, the improvement in temperate 20-km TT performance was not greater for HIIT13 than HIIT35, despite greater T > 90% Vo2max during 13° C HIIT vs. 35° C HIIT. Physiological responses (e.g., HR and thermoregulation) during the TT differed between HIIT13 and HIIT35, indicating varying adaptive responses.
DOI
10.1519/JSC.0000000000005013
Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.
Comments
Boynton, J. R., Peiffer, J. J., & Abbiss, C. R. (2025). Effects of HIIT in cool and hot on temperate performance and physiological response in trained cyclists. The Journal of Strength & Conditioning Research, 39(3). https://doi.org/10.1519/JSC.0000000000005013