Related Experiment Video
Updated: Apr 7, 2026

Skeletal Muscle Gender Dimorphism from Proteomics
Published on: December 14, 2011
Performance differences between male and female marines on standardized physical fitness tests and combat proxy
Objectives:
For decades women have been restricted from direct assignment to certain military occupational specialties such as infantry. These restrictions can limit the advancement of women through the ranks of military leadership. Thus, the purpose of this effort was to identify those physical requirements most likely to serve as barriers for women wanting to enter closed combat arms positions, and to evaluate the quality of existing physical fitness tests as potential measures of assessment of combat readiness.
Methods:
Data were collected from 3 different sites within the US Marine Corps Training and Education Command. All participants (409 male, 379 femaile) were active-duty Marines who recently completed the Physical Fitness Test (PFT) and Combat Fitness Test (CFT). Participants completed 6 physical tasks: 120-mm tank loading drill, 155-mm artillery round carry, negotiating an obstacle course wall while wearing a fighting load (≈30 lb), pull-ups, deadlift, and clean and press.
Results:
Overall, there was a high rate of successful completion on the combat proxy tasks (men, ≈80% to 100%; women, ≈70% to 100%), with the notable exception being the clean and press (men, 80%; women, 9%) and pull-ups (men, 16±4; women, 4±2). The PFT and CFT components tasks were also related, strongly in some cases, with performance on combat-related proxy tasks (Spearman's ρ typically ranged from 0.60 to 0.80). Estimates of fat-free mass and VO2max were also strongly related to an overall measure of combat readiness (Spearman's ρ=0.77 and ρ=0.56, respectively).
Conclusions:
The primary physical obstacle for women is upper body strength. However, some women could successfully complete all of the proxy tasks and thus are physically capable of meeting the demands of closed combat occupations. The fact that some female Marines could complete the most challenging upper body strength tasks suggests that these barriers are not inherent but may be due to a lack of training specificity.
Related Concept Videos
Mate Choice
Exercise and Muscle Performance
Endurance exercises
Endurance exercises involve running, swimming, or cycling, which require repetitive movements with low force output. When a person engages in endurance exercise, a few noticeable changes occur in their skeletal muscles. For instance, the number of capillaries...

