HEAT EXPOSURE AND HYPOHYDRATION EXACERBATE PHYSIOLOGICAL STRAIN DURING LOAD CARRYING.
In: Journal of Strength & Conditioning Research, Jg. 33 (2019-03-01), Heft 3, S. 727-735
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Zugriff:
Adams, EL, Casa, DJ, Huggins, RA, DeMartini-Nolan, JK, Stearns, RL, Kennedy, RM, Bosworth, MM, DiStefano, LJ, Armstrong, LE, and Maresh, CM. Heat exposure and hypohydration exacerbate physiological strain during load carrying. J Strength Cond Res 33(3): 727-735, 2019-Heat exposure and hypohydration induce physiological and psychological strain during exercise; however, it is unknown if the separate effects of heat exposure and hypohydration are synergistic when co-occurring during loaded exercise. This study compared separate and combined effects of heat exposure and hypohydration on physiological strain, mood state, and visual vigilance during loaded exercise. Twelve men (mean ± SD; age, 20 ± 2 years; body mass, 74.0 ± 8.2 kg; maximal oxygen uptake, 57.0 ± 6.0 ml·kg-1 ·min-1) completed 4 trials under the following conditions: euhydrated temperate (EUT), hypohy- drated temperate (HYT), euhydrated hot (EUH), and hypohydrated hot (HYH). Exercise was 90 minutes of treadmill walking (~50% Vo2max, 5% grade) while carrying a 45-lb rucksack. Profile of Mood States and the Scanning Visual Vigilance Test were completed before and after exercise. The separate effects of heat exposure (EUH) and hypohydration (HYT) on post-exercise rectal temperature (Tre) were similar (38.25 ± 0.63°C vs. 38.22 ± 0.29°C, respectively, p > 0.05), whereas in combination (HYH), post-exercise Tre was far greater (39.32 ± 0.43°C). Increase in Tre per 1% body mass loss (BML) for HYH (vs. EUH) was greater than HYT (vs. EUT) (0.32 vs. 0.04°C, respectively, p = 0.02); heart rate increase per 1% BML for HYH (vs. EUH) was 7 b·min-1 compared with HYT (vs. EUT) at 3 b·min-1 (p = 0.30). Hypohydrated hot induced greater mood disturbance (post-exercise - pre-exercise) (35 ± 21 units) compared with other conditions (EUT = 3 ± 9 units; HYT = 3 ± 16 units; EUH = 16 ± 26 units; p < 0.001). No differences occurred in visual vigilance (p > 0.05). Independently, heat exposure and hypohydration induced similar physiological strain during loaded exercise; when combined, heat exposure with hypohydration, synergistically exacerbated physiological strain and mood disturbance. [ABSTRACT FROM AUTHOR]
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HEAT EXPOSURE AND HYPOHYDRATION EXACERBATE PHYSIOLOGICAL STRAIN DURING LOAD CARRYING.
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Autor/in / Beteiligte Person: | ADAMS, ELIZABETH L. ; CASA, DOUGLAS J. ; HUGGINS, ROBERT A. ; DEMARTINI-NOLAN, JULIE K. ; STEARNS, REBECCA L. ; KENNEDY, RACHEL M. ; BOSWORTH, MEGAN M. ; DISTEFANO, LINDSAY J. ; ARMSTRONG, LAWRENCE E. ; MARESH, CARL M. |
Zeitschrift: | Journal of Strength & Conditioning Research, Jg. 33 (2019-03-01), Heft 3, S. 727-735 |
Veröffentlichung: | 2019 |
Medientyp: | academicJournal |
ISSN: | 1064-8011 (print) |
DOI: | 10.1519/jsc.0000000000001831 |
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