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Preloaded Time Trial to Assess Load Carriage Performance

Faghy, Mark A.; Brown, Peter I.

Journal of Strength & Conditioning Research: December 2014 - Volume 28 - Issue 12 - p 3354–3362
doi: 10.1519/JSC.0000000000000555
Original Research

Abstract: Faghy, MA and Brown, PI. Preloaded time trial to assess load carriage performance. J Strength Cond Res 28(12): 3354–3362, 2014—The relevance and importance of load carriage in recreational and occupational tasks has stimulated a large body of research. Exercise protocols have been criticized for a lack of relevance to occupational activities; accordingly, the aim of this study was to assess the reliability of a preloaded time-trial protocol for load carriage assessment. After full familiarization, 8 healthy males performed 2 trials separated by 1 week. Each trial comprised 60-minute walking at 6.5 km·h−1 and 0% gradient (LC), 15 minutes seated recovery followed by a 2.4-km time-trial (LCTT). All trials were performed wearing a 25-kg backpack. Performance time was 16.71 ± 1.82 minutes and 16.37 ± 1.78 minutes for LCTT 1 and 2, respectively with a mean difference of −0.34 ± 0.89 minutes. Using log ratio limits of agreement, the mean bias was 1.02 and random error component of the agreement ratio was 1.11. The intraclass correlation was 0.85, coefficient of variation was 10.5%, and Cohen's d was 0.35. The protocol demonstrated a very good level of reliability. We present a novel and reliable preloaded time-trial protocol that more closely reflects operational activities and can be used to quantify load carriage performance. This protocol provides greater ecologically validity regarding physical demands of load carriage activities than those adopted previously and provides an excellent tool for the strength and conditioning practitioner to assess individual load carriage performance.

Department of Sport and Exercise, School of Science, University of Derby, Derby, United Kingdom

Address correspondence to Mark A. Faghy, M.Faghy@Derby.ac.uk.

Copyright © 2014 by the National Strength & Conditioning Association.