RESEARCH ARTICLE
Loaded and Unloaded Marching: Implications for Fluid Replacement
Susan Dewhurst1, Melissa J. Bargh, Chester Davidson , Theodoros M. Bampouras
Article Information
Identifiers and Pagination:
Year: 2014Volume: 7
First Page: 16
Last Page: 21
Publisher ID: TOSSJ-7-16
DOI: 10.2174/1875399X01407010016
Article History:
Received Date: 01/05/2013Revision Received Date: 06/06/2013
Acceptance Date: 25/08/2013
Electronic publication date: 24/01/2014
Collection year: 2014
open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC-BY 4.0), a copy of which is available at: https://creativecommons.org/licenses/by/4.0/legalcode. This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Abstract
Marching with essential survival equipment is a fundamental military exercise. A consequence of this increased load is an increased risk of dehydration. Dehydration may have fatal consequences in a combat situation where performance must be optimal. This risk can be minimized with an understanding of the additional fluid needs of soldiers marching when loaded compared to unloaded. The aim of this study was to quantify fluid loss caused by marching with a loaded Bergen rucksack and webbing of 33.5 kg for 45 minutes when compared to unloaded carriage in eight healthy male officer cadets (age, 20.5 ± 0.9 years; body mass 80.2 ± 9.2 kg). The findings demonstrate an increased rate of sweat loss (0.6 ± 0.2 L·h-1 to 1.2 ± 0.4 L·h-1; p<0.001) and increased average heart rate (105.5 ± 17.7 beats·min-1 to 136.6 ± 28.3 beats·min-1; p<0.001) for unloaded and loaded trial respectively. Urine osmolality significantly increased pre- to postmarch (p<0.05), however there was no difference in this increase between the loaded and unloaded trial. The present study demonstrated that marching with a loaded rucksack and webbing increased sweat rate by 100% compared to the same march with no additional load. For soldiers to prevent dehydration and the potential detrimental effects on performance, fluid replacement should also be doubled when marching with loading in a temperate environment, however individual differences in sweat rate should be taken into account.
