Effects of a 10-d Military Field Exercise on Body Composition, Physical Performance, and Muscle Cells in Men and Women.

Autor:	Vikmoen O, Teien HK; Norwegian Defence Research Establishment, Comprehensive Defence Division, Kjeller, NORWAY., Tansø R; Norwegian Defence Research Establishment, Comprehensive Defence Division, Kjeller, NORWAY., Aandstad A; Norwegian Defence University College, Norwegian Defence Command and Staff College, Section for Military Leadership and Sport, Oslo, NORWAY., Lander E; Norwegian School of Sport Sciences, Department of Physical Performance, Oslo, NORWAY., Cumming KT, Ellefsen S; Inland Norway University of Applied Sciences, Faculty for Health and Social Sciences, Lillehammer, NORWAY., Helkala K; The Norwegian Defense University College, Norwegian Defence Cyber Academy, Lillehammer, NORWAY., Raastad T; Norwegian School of Sport Sciences, Department of Physical Performance, Oslo, NORWAY.
Jazyk:	angličtina
Zdroj:	Medicine and science in sports and exercise [Med Sci Sports Exerc] 2024 Apr 01; Vol. 56 (4), pp. 682-696. Date of Electronic Publication: 2023 Nov 13.
DOI:	10.1249/MSS.0000000000003340
Abstrakt:	Purpose: This study aimed to investigate the effects of a demanding military field exercise on physical performance, body composition, and muscle cellular outcomes in men and women. Methods: Ten men (20.5 ± 0.5 yr) and 8 women (21.4 ± 1.4 yr) completed a 10-d field exercise consisting of extensive physical activity with food and sleep restriction. Acquisition of body composition, physical performance, blood, and muscle biopsies samples were done before and 1, 7, and 14 d after the exercise. Results: There were no sex differences in the response to the exercise. Body mass was decreased with 5.6% ± 1.8% and fat mass with 31% ± 11% during the exercise. Both were still reduced after 14 d (2.5% ± 2.3%, P < 0.001, and 12.5% ± 7.7%, P < 0.001, respectively). Isometric leg strength did not change. Peak leg extension torque at 240°·s -1 and counter movement jump height were reduced with 4.6% ± 4.8% ( P = 0.012) and 6.7% ± 6.2% ( P < 0.001), respectively, and was still reduced after 14 d (4.3% ± 4.2%, P = 0.002, and 4.1% ± 4.7%, P = 0.030). No changes occurred in fiber CSA, fiber types, proteins involved in calcium handling, or HSP70. During the exercise, αB-crystallin levels decreased by 14% ± 19% ( P = 0.024) in the cytosolic fraction and staining intensity on muscle sections tended to increase (17% ± 25%, P = 0.076). MuRF1 levels in the cytosolic fraction tended to decrease (19% ± 35%) and increased with 85% ± 105% ( P = 0.003) in the cytoskeletal fraction 1 wk after the exercise. Conclusions: The field exercise resulted in reduced body mass and physical performance in both sexes. The ability to produce force at high contraction velocities and explosive strength was more affected than isometric strength, but this was not related to any changes in fiber type composition, fiber area, Ca 2+ handling, or fiber type-specific muscle damage. (Copyright © 2023 by the American College of Sports Medicine.)
Databáze:	MEDLINE
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