Article Title



Burgy, K., Kwon, M., Hale, D. & Kollock, R.O.; The University of Tulsa, Tulsa, OK

Load carriage is the act of carrying an external load on the body to assist with a performing a specific task. The investigation of load carriage (LC) and its impact on treadmill performance has occurred in mostly military populations. Therefore, very little data exists with non-tactical populations, such as runners and LC during treadmill running conditions. PURPOSE: The purpose of this study was to assess oxygen uptake (VO2), heart rate(HR), and respiratory exchange ratio (RER) potential differences between three treadmill conditions. METHODS: Following IRB approval, ten college students (5 males and 5 females), who were active runners, completed three trials of a self-paced 5K on a treadmill (incline 1%). The ten participants (ages: 20.1±1.7) completed three trials on a treadmill with at least 48-hours between testing sessions. The three treadmill conditions consisted of a self-paced 5K, one without a wearable hydration system(control condition), one with a backpack hydration system, and one with a handheld hydration system. Weight of each LC condition (backpack and handheld) was equal (1.2kg or <3lbs). All three variables were assessed using the iWorx HEK-PEAK metabolic system. Three separate one-way ANOVA tests were used to compare differences of the three variables between the three trials with appropriate post-hoc comparisons. RESULTS: Prior to statistical analyses data was determined to be from a normal distribution. Results from the three one-way ANOVA tests indicated an overall difference in VO2(F: 4.2, p= .002) and RER (F: 5.5, p= .03) with no significant difference in HR detected between the three trials. Post-hoc comparisons(LSD)for VO2determined the main difference was between the handheld trial (34.3±3.7ml/kg-1/min-1) and the unloaded trial (32.1±2.4ml/kg-1/min-1). A similar finding was detected with post-hoc comparisons between RER with a significant difference detected between the handheld trial (.95±.14) and the unloaded trial (.87±.21). CONCLUSION: Results of the current study indicate that the VO2and substrate (RER) utilization increased the most during the handheld trial versus the other two trials while HR remained slightly unchanged. Based on these results, it appears that a handheld hydration system may increase metabolic rate on a runner more than an unloaded or backpack based system. Even though HR was not significantly different between the three trials, the handheld trial elicited the highest mean HR (168±4.5). Limitations for this study include a small sample size, the shorter duration of the running conditions, and the 5K was submaximal. Future directions should include investigation of other hydration pack configurations on metabolic cost while running.

ACKNOWLEDGEMENTS: This study was funded by The University of Tulsa Undergraduate Research Challenge Program.

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