Extending Air Force Physical Fitness Postpartum Dwell Time Improves Maternal Physical Readiness

Research suggests women are more likely to fail their military physical fitness assessment in the immediate postpartum period than in the prenatal period. In 2015, the United States Air Force physical fitness postpartum testing dwell time increased from 6 months to 12 months postpartum. The primary aim of this study was to assess if Air Force active duty women's physical readiness, as indicated by individual physical fitness test results, was impacted by this change. The secondary aim was to determine the postpartum duration for active duty Air Force women to return to their prenatal anthropometric measurements.

All active duty Air Force women who gave birth from 2011-2019 in the military medical system were considered for analysis. A total of 6,726 women meeting inclusion criteria were grouped to 6 month testers (delivery between 2011-February 2015) and 12 month testers (delivery between March 2015 and 2019). Logistic regression and general linear models were used to assess the associations and predictability of the various fitness and anthropometric components of the physical fitness testing requirements (6 vs. 12 month testers), controlling for covariates (age, military rank, marital status, and ethnicity).

Those testing at 12 months had decreased odds (odds ratio = 0.40, 95% CI = 0.32-0.49, P < .0001) of failing their initial postpartum fitness test than those testing at 6 months. The prevalence of test failure at the first exam postpartum was 10.4% among 6 month testers and 4% among 12 month testers. Women who tested at 6 months retained relatively more weight (2.7 ± 5.0 kg, 4.2% increase), body mass index (1.0 ± 2.1 kg/m2, 4.5% increase), and abdominal circumference (2.4 ± 4.9 cm, 3.5% increase) than their counterparts testing at 12 months (1.8 ± 5.4 kg, 2.8% increase; 0.7 ± 2.2 kg/m2, 3.0% increase; and 1.8 ± 5.0 cm, 2.7% increase; respectively) (P < .0001). When comparing those with prenatal fitness status of "excellent," "pass," or "fail," no group attained prenatal weight status in the 24 months monitored. Average weight and abdominal circumference retention for all groups at 24 months postpartum were 2.8 kg and 1.3 cm, respectively. Among initial postpartum fitness testing failures, the component most failed was sit-ups (34.5%), followed by the 1.5-mile run (29.8%). Six month testers were more likely, across all prenatal fitness categories ("fail," "pass" and "excellent") to fail postpartum fitness testing compared to 12 month testers (26.1%, 17.7%, and 5.6% vs.19.4%, 7.3% and 2%, respectively).

The decision of the Air Force to increase the minimal required time between childbirth and postpartum physical fitness testing for women has positively impacted fitness test failure rates and anthropometric measure changes. Additional policy should be implemented to support postpartum holistic health interventions.