Tags

Type your tag names separated by a space and hit enter

The effect of cycling in the heat on gastrointestinal-induced damage and neuromuscular fatigue.

Abstract

PURPOSE

This study investigated the effect of exercise in the heat on neuromuscular function, gastrointestinal damage, endotoxemia and inflammatory cytokines.

METHODS

Eight male cyclists completed two 60 min cycling trials in both hot (HOT 34.5 ± 0.1 °C and 53 ± 1% relative humidity) and temperate environments (CON 20.2 ± 0.3 °C and 55 ± 3% relative humidity). The cycling task comprised of alternating 3 min intervals at a moderate-vigorous intensity (50% and 70% of maximum power output; Pmax) for 30 min, followed by 30 min at moderate intensity (40-50% Pmax). Neuromuscular function was assessed at pre-, post-exercise and 60 min post-exercise. Circulating levels of endotoxins, inflammatory cytokines and markers of gut permeability and damage were also collected at these time points. Heart rate, core temperature, skin temperature, perceived exertion, thermal sensation and comfort were also measured.

RESULTS

Post-exercise voluntary activation of HOT (87.9% [85.2, 90.8]) was statistically lower (mean difference - 2.5% [- 4.5, - 0.5], d = 2.50) than that of CON (90.5% [87.8, 93.2]). The HOT trial resulted in statistically elevated (+ 69%) markers of gastrointestinal damage compared to CON (mean difference 0.424 ng mL-1 [0.163, 0.684, d = - 3.26]), although this was not observed for endotoxin, other inflammatory markers, or gastrointestinal permeability.

CONCLUSIONS

This research provides evidence that short-duration cycling in the heat results in sub-optimal neuromuscular activation and increased expression of gastrointestinal damage markers, without a simultaneous elevation in circulating endotoxins or pro-inflammatory cytokines.

Links

  • Publisher Full Text
  • Authors+Show Affiliations

    ,

    School of Exercise and Nutrition Sciences, Queensland University of Technology, Brisbane, QLD, Australia. john.osborne@hdr.qut.edu.au. Institute of Health and Biomedical Innovation, Queensland University of Technology, 60 Musk Avenue, Kelvin Grove, Brisbane, QLD, 4059, Australia. john.osborne@hdr.qut.edu.au.

    ,

    School of Exercise and Nutrition Sciences, Queensland University of Technology, Brisbane, QLD, Australia. Institute of Health and Biomedical Innovation, Queensland University of Technology, 60 Musk Avenue, Kelvin Grove, Brisbane, QLD, 4059, Australia.

    ,

    Institute of Health and Biomedical Innovation, Queensland University of Technology, 60 Musk Avenue, Kelvin Grove, Brisbane, QLD, 4059, Australia. School of Biomedical Sciences, Queensland University of Technology, Brisbane, QLD, Australia.

    School of Exercise and Nutrition Sciences, Queensland University of Technology, Brisbane, QLD, Australia. Institute of Health and Biomedical Innovation, Queensland University of Technology, 60 Musk Avenue, Kelvin Grove, Brisbane, QLD, 4059, Australia.

    Source

    European journal of applied physiology 119:8 2019 Aug pg 1829-1840

    Pub Type(s)

    Journal Article

    Language

    eng

    PubMed ID

    31175438

    Citation

    Osborne, John O., et al. "The Effect of Cycling in the Heat On Gastrointestinal-induced Damage and Neuromuscular Fatigue." European Journal of Applied Physiology, vol. 119, no. 8, 2019, pp. 1829-1840.
    Osborne JO, Stewart IB, Beagley KW, et al. The effect of cycling in the heat on gastrointestinal-induced damage and neuromuscular fatigue. Eur J Appl Physiol. 2019;119(8):1829-1840.
    Osborne, J. O., Stewart, I. B., Beagley, K. W., & Minett, G. M. (2019). The effect of cycling in the heat on gastrointestinal-induced damage and neuromuscular fatigue. European Journal of Applied Physiology, 119(8), pp. 1829-1840. doi:10.1007/s00421-019-04172-z.
    Osborne JO, et al. The Effect of Cycling in the Heat On Gastrointestinal-induced Damage and Neuromuscular Fatigue. Eur J Appl Physiol. 2019;119(8):1829-1840. PubMed PMID: 31175438.
    * Article titles in AMA citation format should be in sentence-case
    TY - JOUR T1 - The effect of cycling in the heat on gastrointestinal-induced damage and neuromuscular fatigue. AU - Osborne,John O, AU - Stewart,Ian B, AU - Beagley,Kenneth W, AU - Minett,Geoffrey M, Y1 - 2019/06/07/ PY - 2019/04/03/received PY - 2019/06/03/accepted PY - 2019/6/9/pubmed PY - 2019/6/9/medline PY - 2019/6/9/entrez KW - Central fatigue KW - Cycling KW - Endotoxemia KW - Hyperthermia KW - Thermoregulation SP - 1829 EP - 1840 JF - European journal of applied physiology JO - Eur. J. Appl. Physiol. VL - 119 IS - 8 N2 - PURPOSE: This study investigated the effect of exercise in the heat on neuromuscular function, gastrointestinal damage, endotoxemia and inflammatory cytokines. METHODS: Eight male cyclists completed two 60 min cycling trials in both hot (HOT 34.5 ± 0.1 °C and 53 ± 1% relative humidity) and temperate environments (CON 20.2 ± 0.3 °C and 55 ± 3% relative humidity). The cycling task comprised of alternating 3 min intervals at a moderate-vigorous intensity (50% and 70% of maximum power output; Pmax) for 30 min, followed by 30 min at moderate intensity (40-50% Pmax). Neuromuscular function was assessed at pre-, post-exercise and 60 min post-exercise. Circulating levels of endotoxins, inflammatory cytokines and markers of gut permeability and damage were also collected at these time points. Heart rate, core temperature, skin temperature, perceived exertion, thermal sensation and comfort were also measured. RESULTS: Post-exercise voluntary activation of HOT (87.9% [85.2, 90.8]) was statistically lower (mean difference - 2.5% [- 4.5, - 0.5], d = 2.50) than that of CON (90.5% [87.8, 93.2]). The HOT trial resulted in statistically elevated (+ 69%) markers of gastrointestinal damage compared to CON (mean difference 0.424 ng mL-1 [0.163, 0.684, d = - 3.26]), although this was not observed for endotoxin, other inflammatory markers, or gastrointestinal permeability. CONCLUSIONS: This research provides evidence that short-duration cycling in the heat results in sub-optimal neuromuscular activation and increased expression of gastrointestinal damage markers, without a simultaneous elevation in circulating endotoxins or pro-inflammatory cytokines. SN - 1439-6327 UR - https://www.unboundmedicine.com/medline/citation/31175438/The_effect_of_cycling_in_the_heat_on_gastrointestinal-induced_damage_and_neuromuscular_fatigue L2 - https://dx.doi.org/10.1007/s00421-019-04172-z DB - PRIME DP - Unbound Medicine ER -