Muscle-Damaging Exercise Increases Heat Strain during Subsequent Exercise Heat Stress

Fortes, M.B., Di Felice, U., Dolci, A., Junglee, N.A., Crockford, M.J., West, L., Hillier-Smith, R., Macdonald, J.H. and Walsh, N.P. 2013. Muscle-Damaging Exercise Increases Heat Strain during Subsequent Exercise Heat Stress. Medicine & Science in Sports & Exercise. 45 (10), p. 1915–1924. doi:10.1249/MSS.0b013e318294b0f8

TitleMuscle-Damaging Exercise Increases Heat Strain during Subsequent Exercise Heat Stress
AuthorsFortes, M.B., Di Felice, U., Dolci, A., Junglee, N.A., Crockford, M.J., West, L., Hillier-Smith, R., Macdonald, J.H. and Walsh, N.P.
Abstract

Purpose:
It remains unclear whether exercise-induced muscle damage (EIMD) increases heat strain during subsequent exercise heat stress, which in turn may increase the risk of exertional heat illness. We examined heat strain during exercise heat stress 30 min after EIMD to coincide with increases in circulating pyrogens (e.g., interleukin-6 [IL-6]) and 24 h after EIMD to coincide with the delayed muscle inflammatory response when a higher rate of metabolic energy expenditure (M˙) and thus decreased economy might also increase heat strain.

Methods:
Thirteen non-heat-acclimated males (mean ± SD, age = 20 ± 2 yr) performed exercise heat stress tests (running for 40 min at 65% V˙O2max in 33°C, 50% humidity) 30 min (HS1) and 24 h (HS2) after treatment, involving running for 60 min at 65% V˙O2max on either -10% gradient (EIMD) or +1% gradient (CON) in a crossover design. Rectal (Tre) and skin (Tsk) temperature, local sweating rate, and M˙ were measured throughout HS tests.

Results:
Compared with CON, EIMD evoked higher circulating IL-6 pre-HS1 (P < 0.01) and greater plasma creatine kinase and muscle soreness pre-HS2 (P < 0.01). The ΔTre was greater after EIMD than CON during HS1 (0.35°C, 95% confidence interval = 0.11°C-0.58°C, P < 0.01) and HS2 (0.17°C, 95% confidence interval = 0.07°C-0.28°C, P < 0.01). M˙ was higher on EIMD throughout HS1 and HS2 (P < 0.001). Thermoeffector responses (Tsk, sweating rate) were not altered by EIMD. Thermal sensation and RPE were higher on EIMD after 25 min during HS1 (P < 0.05). The final Tre during HS1 correlated with the pre-HS1 circulating IL-6 concentration (r = 0.67).

Conclusions:
Heat strain was increased during endurance exercise in the heat conducted 30 min after and, to a much lesser extent, 24 h after muscle-damaging exercise. These data indicate that EIMD is a likely risk factor for exertional heat illness particularly during exercise heat stress when beuhavioral thermoregulation cues are ignored.

KeywordsTHERMOREGULATION, ECCENTRIC, HYPERTHERMIA, HEAT ILLNESS, HEAT STROKE, INFLAMMATION
JournalMedicine & Science in Sports & Exercise
Journal citation45 (10), p. 1915–1924
ISSN0195-9131
Year2013
PublisherAmerican College of Sports Medicine
Digital Object Identifier (DOI)doi:10.1249/MSS.0b013e318294b0f8
Publication dates
PublishedOct 2013

Related outputs

The Effect of Omega-3 Supplementation on Exercise-Induced Muscle Damage
Kyriakidou, Y., Wood, C., Elliott, B. and Dolci, A. 2018. The Effect of Omega-3 Supplementation on Exercise-Induced Muscle Damage. Europhysiology 2018. London 14 - 16 Sep 2018 The Physiological Society.

Portable prehospital methods to treat near-hypothermic shivering cold casualties
Oliver, S.J., Brierley, J.L., Raymond-Barker, P.C., Dolci, A. and Walsh, N.P. 2016. Portable prehospital methods to treat near-hypothermic shivering cold casualties. Wilderness & Environmental Medicine. 27 (1), pp. 125-130. doi:10.1016/j.wem.2015.11.012

A randomized trial to assess the potential of different beverages to affect hydration status: development of a beverage hydration index
Maughan, R.J., Watson, P., Cordery, P.A.A., Walsh, N.P., Oliver, S.J., Dolci, A., Rodriguez-Sanchez, N. and Galloway, S.D.R. 2016. A randomized trial to assess the potential of different beverages to affect hydration status: development of a beverage hydration index. American Journal of Clinical Nutrition. 103, pp. 717-723. doi:10.3945/ajcn.115.114769

Repeated muscle damage blunts the increase in heat strain during subsequent exercise heat stress
Dolci, A., Fortes, M.B., Walker, F.S., Haq, A., Riddle, T. and Walsh, N.P. 2015. Repeated muscle damage blunts the increase in heat strain during subsequent exercise heat stress. European Journal of Applied Physiology. 115 (7), pp. 1577-1588. doi:10.1007/s00421-015-3143-7

Exercising in a hot environment with muscle damage: Effects on acute kidney injury biomarkers and kidney function
Junglee, N.A., Di Felice, U., Dolci, A., Fortes, M.B., Jibani, M.M., Lemmey, A.B., Walsh, N.P. and Macdonald, J.H. 2013. Exercising in a hot environment with muscle damage: Effects on acute kidney injury biomarkers and kidney function. American Journal of Physiology Renal Physiology. 305 (6), pp. F813-F820. doi:10.1152/ajprenal.00091.2013

Permalink - https://westminsterresearch.westminster.ac.uk/item/9v821/muscle-damaging-exercise-increases-heat-strain-during-subsequent-exercise-heat-stress


Share this
Tweet
Email