Research Paper Title

Cardiorespiratory responses to heavy military load carriage over complex terrain.

Background

This study examined complex terrain march performance and cardiorespiratory responses when carrying different Soldier loads.

Methods

Nine active duty military personnel (age, 21 ± 3 yr; height, 1.72 ± 0.07 m; body mass (BM), 83.4 ± 12.9 kg) attended two test visits during which they completed consecutive laps around a 2.5-km mixed terrain course with either a fighting load (30% BM) or an approach load (45% BM).

Respiratory rate and heart rate data were collected using physiological status monitors.

Training impulse (TRIMP) scores were calculated using Banister’s formula to provide an integrated measure of both time and cardiorespiratory demands. Completion times were not significantly different between the fighting and approach loads for either Lap 1 (p = 0.38) or Lap 2 (p = 0.09).

Results

Respiration rate was not significantly higher with the approach load than the fighting load during Lap 1 (p = 0.17) but was significantly higher for Lap 2 (p = 0.04).

However, heart rate was significantly higher with the approach load versus the fighting load during both Lap 1 (p = 0.03) and Lap 2 (p = 0.04).

Furthermore, TRIMP was significantly greater with the approach load versus the fighting load during both Lap 1 (p = 0.02) and Lap 2 (p = 0.02).

Conclusions

Trained military personnel can maintain similar pacing while carrying either fighting or approach loads during short mixed terrain marches.

However, cardiorespiratory demands are greatly elevated with the approach load and will likely continue to rise during longer distance marches.

Reference

Looney, D.P., Santee, W.R., Blanchard, L.A., Karis, A.J., Carter, A.J. & Potter, A.W. (2018) Cardiorespiratory responses to heavy military load carriage over complex terrain. Applied Ergonomics. 73:194-198. doi: 10.1016/j.apergo.2018.07.010. Epub 2018 Jul 24.