A preliminary study of the effects of load carriage on cognition during a simulated military task in male and female soldiers

Nicola Armstrong, Darren Doyle, Sarah Smith, Debbie Risius, Sophie Wardle, Julie Greeves, James R. House

Research output: Contribution to conferenceAbstractpeer-review


Purpose: The aim of this study was to evaluate the effect of carrying loads of varying masses on cognitive performance during prolonged marching.

Methods: Twelve male and ten female soldiers conducted four 12.25 km treadmill marches (4.9 km h−1 in 3 × 50 min sessions) in different load configurations (21 kg, 26 kg, 33 kg and 43 kg). A bespoke task was developed to measure responses to auditory and visual targets (Go/No go), working memory was measured using the well-established 0, 1, 2 and 3 n-backs. The exercise intensity remained moderate (31% to 55% of V02max) throughout the 3 h march for both sexes regardless of load carried or duration. 7/12 males and 1/10 females completed the full march in each load. Participants withdrew from the test due to self-reported discomfort (blisters, chaffing and muscular discomfort). Some participants continued marching but opted not to complete the cognitive tests due to discomfort. In women, statistical analysis was not appropriate for all loads and time points due to low participant completions. N-back tests were conducted towards the end of each 50 min march. Go/No go tasks were conducted at the start and mid-point of each march.

Results: In men, overall accuracy was unaffected by time. However, accuracy was significantly reduced by 3–20% during 1–3 n-backs in the 43 kg load. In women, accuracy reduced by 5–8% in the 26 kg load and 3–11% in the 33 kg load across all n-backs and over time. During the visual task, reductions in accuracy were observed with load (up to 20% (men) and 26% (women)), with no differences in accuracy between men and women (69–89% (men) and 65–90% overall accuracy (women), respectively). Accuracy during the auditory task was significantly reduced with load and over time in the female group only. Accuracy was also significantly decreased in women wearing the heavier loads when compared to men. Accuracy ranged from 93 to 97% in men and 77 to 97% in women.

Conclusions: Initial data indicate that soldiers are less able to manage cognitive demands as mass carried and duration of marching increases. This reduces accuracy during cognitive tasks, and these effects are more pronounced in women than men. However, these results should be interpreted with some caution given the high number of test withdrawals. Future work should explore the independent impact of load discomfort on cognition.
Original languageEnglish
Publication statusPublished - 15 Nov 2017
Event4th International Congress on Soldiers’ Physical Performance - Melbourne, Australia
Duration: 28 Nov 20171 Dec 2017


Conference4th International Congress on Soldiers’ Physical Performance
Internet address


  • body armour
  • soldiers
  • male & female
  • cognition


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