Volume 4 Supplement 1

15th International Conference on Environmental Ergonomics (ICEE XV)

Open Access

The effects of water temperature on physiological responses and exercise performance during immersed incremental exercise

  • Tomomi Fujimoto1Email author,
  • Yosuke Sasaki1,
  • Hitoshi Wakabayashi2,
  • Yasuo Sengoku3,
  • Shozo Tsubakimoto3 and
  • Takeshi Nishiyasu3
Extreme Physiology & Medicine20154(Suppl 1):A37

DOI: 10.1186/2046-7648-4-S1-A37

Published: 14 September 2015

Introduction

Aquatic exercise such as swimming is performed in the water of 18 to 34 °C because of the differences in ambient environmental conditions. Heat conductivity of water is greater than that of air, therefore water temperature would have a considerable impact on physiological responses and exercise performance. A previous study has shown that, oxygen consumption (V(·)O2) during immersed cycle exercise at submaximal workload is greater in cold water (18 °C) compared to moderately cool and warm water (25 and 34 °C) [1]. Furthermore, previous studies have reported decreased V(·)O2 at maximal work (V(·)O2peak) in the cold water [2], while others have reported no change [3]. Therefore, consensus views on whether difference in water temperature affects V(·)O2peak and exercise performance hasn't been obtained. The purpose of this study was to investigate the effects of water temperature on physiological responses and exercise performance using immersed incremental cycle exercise until exhaustion.

Methods

Ten healthy young men performed incremental exercise on a water cycle ergometer in a semi-recumbent position. The subjects immersed to their shoulders and performed the exercise in 3 water temperatures (Tw): 18, 26 and 34 °C. For the exercise, initial workload was 60W and increased 20 W every 2 minutes at first 4 levels, and then increased 10 W every minute until they would no longer continue. The workload was increased by electrical brake whilst keeping a constant pedalling rate (60 rpm) in an attempt to avoid changes in the water external force exerted on the legs. Oesophageal temperature, skin temperature, expired gases, heart rate and maximal workload were measured. This research conformed to the principles of the Declaration of Helsinki, and all subjects signed an informed consent form.

Results

During submaximal exercise (60 to 120 W), V(·)O2 was higher in Tw 18 compared to other conditions (Tw 26 and 34). While maximal workload in Tw 18 was lower than in the other conditions (Tw 18 mean (SD): 138(16) W, Tw 26: 157(15) W, Tw 34: 156(18) W), V(·)O2peak did not differ among conditions (Tw 18: 3156(364) mL.min-1, Tw 26: 3270(344) mL.min-1, Tw 34: 3281(268) mL.min-1). Minute ventilation during maximal and submaximal exercise and tidal volume during submaximal exercise were higher in Tw 18 compared to the other conditions, while respiratory frequency did not differ between conditions.

Discussion

The lower maximal workload in Tw 18 may be due to the fact that, even though V(·)O2peak was same level among all conditions, it reached peak values faster in Tw 18 compared to the other conditions, since V(·)O2 in Tw 18 during submaximal exercise was already elevated. The enhanced ventilatory response in Tw 18 was the result of the enhanced tidal volume rather than respiratory frequency.

Conclusion

During immersed incremental cycle exercise, exercise performance decreases in cold water (18 °C ) due to V(·)O2 reaching peak values faster. Ventilatory response (Vt) is enhanced in cold water (18 °C).

Authors’ Affiliations

(1)
Graduate School of Comprehensive Human Sciences, University of Tsukuba
(2)
Faculty of Engineering, Chiba Institute of Technology
(3)
Institute of Health and Sport Sciences, University of Tsukuba

References

  1. McArdle WD, Magel JR, Lesmes GR, Pechar GS: Metabolic and cardiovascular adjustment to work in air and water at 18, 25, and 33 degrees C. J Appl Physiol. 1976, 40: 85-90.PubMedGoogle Scholar
  2. Rennie DW, Park Y, Veicsteinas A, Pendergast DR: Metabolic and circulatory adaptation to cold water stress. Exercise Bioenergetics and Gas Exchange. 1980, 315-321.Google Scholar
  3. Dressendorfer RH, Morlock JF, Baker DG, Hong SK: Effects of head-out water immersion on cardiorespiratory responses to maximal cycling exercise. Undersea Biomed Res. 1976, 3: 177-87.PubMedGoogle Scholar

Copyright

© Fujimoto et al.; 2015

This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

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