James et al. 2015. Finally accepted version.pdf (167.76 kB)
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Electrolyte supplementation during severe energy restriction increases exercise capacity in the heat

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journal contribution
posted on 07.04.2016, 10:18 by Lewis JamesLewis James, Stephen MearsStephen Mears, Susan M. Shirreffs
PURPOSE. This study examined the effects of sodium chloride and potassium chloride supplementation during 48-h severe energy restriction on exercise capacity in the heat. METHODS. Nine males completed three 48-h trials: adequate energy intake (100 % requirement), adequate electrolyte intake (CON); restricted energy intake (33 % requirement), adequate electrolyte intake (ER-E); and restricted energy intake (33 % requirement), restricted electrolyte intake (ER-P). At 48 h, cycling exercise capacity at 60 % V˙V˙O2 peak was determined in the heat (35.2 °C; 61.5 % relative humidity). RESULTS. Body mass loss during the 48 h was greater during ER-P [2.16 (0.36) kg] than ER-E [1.43 (0.47) kg; P < 0.01] and CON [0.39 (0.68) kg; P < 0.001], as well as greater during ER-E than CON (P < 0.01). Plasma volume decreased during ER-P (P < 0.001), but not ER-E or CON. Exercise capacity was greater during CON [73.6 (13.5) min] and ER-E [67.0 (17.2) min] than ER-P [56.5 (13.1) min; P < 0.01], but was not different between CON and ER-E (P = 0.237). Heart rate during exercise was lower during CON and ER-E than ER-P (P < 0.05). CONCLUSIONS. These results demonstrate that supplementation of sodium chloride and potassium chloride during energy restriction attenuated the reduction in exercise capacity that occurred with energy restriction alone. Supplementation maintained plasma volume at pre-trial levels and consequently prevented the increased heart rate observed with energy restriction alone. These results suggest that water and electrolyte imbalances associated with dietary energy and electrolyte restriction might contribute to reduced exercise capacity in the heat.

History

School

  • Sport, Exercise and Health Sciences

Published in

EUROPEAN JOURNAL OF APPLIED PHYSIOLOGY

Volume

115

Issue

12

Pages

2621 - 2629 (9)

Citation

JAMES, L., MEARS, S. and SHIRREFFS, S., 2015. Electrolyte supplementation during severe energy restriction increases exercise capacity in the heat. European Journal of Applied Physiology, 115 (12), pp.2621-2629.

Publisher

© Springer

Version

AM (Accepted Manuscript)

Publisher statement

This work is made available according to the conditions of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) licence. Full details of this licence are available at: https://creativecommons.org/licenses/by-nc-nd/4.0/

Publication date

2015

Notes

The final publication is available at Springer via http://dx.doi.org/10.1007/s00421-015-3254-1.

ISSN

1439-6319

Language

en