Abstract details

Abstract-ID: 575
Title of the paper: Soldiering Tasks’ Physiological Demands by Heart Rate Zone Scores
Authors: Canino, M., Foulis, S., Cohen, B., Walker, L., Taylor, K., Redmond, J., Sharp, M.
Institution: U.S. Army Research Institute of Environmental Medicine
Department: Military Performance Division
Country: United States
Abstract text INTRODUCTION:
Monitoring heart rate is a prevalent method used in athletics to gauge physical training intensity and recovery in order to produce optimal adaptations. To quantify heart rate training load, summated heart rate zone (SumHR) scores have been utilized by calculating the duration spent in 5 heart rate zones during an activity (1). Advanced physiological measurements (e.g., metabolics, biomarkers) have been previously used in military populations to quantify the physiological demands required to perform high physically demanding military tasks; however, calculating SumHR scores have not been extensively investigated in military populations performing physically demanding occupational tasks. To determine the relationship between total absolute oxygen consumption (AbsVO2) and SumHR scores in Soldiering tasks.
Ten Soldiers (8 males, 2 females) performed 4 Soldiering tasks: foot march (FM), sandbag fill (SBF), sandbag carry (SBC), and ammunition can carry (AMMO). FM required Soldiers to walk for 20 min on a treadmill (2.0-2.5 mph at 0% grade), while wearing 102 lb of equipment. SBF entailed shoveling loose sand into a bucket (30-40 lb) within 52 minutes for 26 fills, while wearing 71 lb of equipment. SBC consisted of lifting and carrying 26 sandbags (40 lb each) a distance of 10 m to construct a fighting position within 26 min, while wearing 71 lb of equipment. AMMO required lifting and carrying 30 ammunition cans (45 lb each) a distance of 15 m and placing them on a vehicle’s tailgate as fast as possible, while wearing 71 lb of equipment. Metabolic measurements and heart rate were monitored and recorded. Age-predicted maximal heart rate was calculated (220-age). SumHR were calculated by multiplying the duration (min) spent in each of the 5 heart rate zones by a multiplier factor for each zone (50-59%=1, 60-69%=2, 70-79%=3, 80-89%=4, =90%=5). Pearson and Spearman correlations were performed to examine the relationship between AbsVO2 and SumHR.
For SBF and SBC, significant positive correlations exist between AbsVO2 and SumHR (r=0.75, p=0.01; rho=0.82, p<0.01). AMMO had a significant positive r=0.82 (p<0.01) but nonsignificant rho (p=0.07). No significant correlations were revealed for FM (p=0.27).
A linear relationship exists between the total absolute oxygen consumption and SumHR scores, indicating individuals with higher AbsVO2 values tended to have higher SumHR scores. Calculating SumHR scores may be an acceptable and feasible alternative to metabolic measurements when attempting to assess the physiological demands during Soldiering tasks; however, caution should be used for constrained tasks (e.g., treadmill FM) due to the potential inability to detect significant performance differences.
1) Foster et al., J Strength Cond Res, 2001.
The views expressed in this abstract are those of the authors and do not reflect the official policy of the Department of Army, Department of Defense, or the U.S. Government.
Topic: Training and Testing
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