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Updated: Sep 29, 2025

A Real-World High-Intensity Interval Training Protocol for Cardiorespiratory Fitness Improvement
Published on: February 22, 2022
Baseline Physical Activity Behaviors and Relationships with Fitness in the Army Training at High Intensity Study
Katie M Heinrich1, Aspen E Streetman1, Filip Kukić2
1Department of Kinesiology, Kansas State University, Manhattan, KS 66506, USA.
Abstract:
United States Army soldiers must meet physical fitness test standards. Criticisms of the Army Physical Fitness Test (APFT) include limited testing of only aerobic and muscular endurance activity domains; yet, it is unclear what levels of aerobic and muscle strengthening activity may help predict performance in aspects of the new Army Combat Fitness Test (ACFT). This study explored relationships between baseline self-reported aerobic and muscle strengthening activities and APFT- and ACFT-related performance. Baseline participant data (N = 123) were from a cluster-randomized clinical trial that recruited active-duty military personnel (mean age 33.7 ± 5.7 years, 72.4% White, 87.0% college-educated, 81.5% Officers). An online survey was used for self-report of socio-demographic characteristics and weekly aerobic and muscle-strengthening physical activity behaviors. Participants also completed the APFT (2 min push-ups, 2 min sit-ups, 2-mile run) and ACFT-related measures (1-repetition maximum deadlift, pull-up repetitions or timed flexed arm hang, horizontal jump, and dummy drag). Bivariate logistic regression found greater aerobic and muscle-strengthening activity predicted better APFT performance, while better ACFT-related performance was predicted by greater muscle-strengthening activity. Although our data are mostly from mid-career officers, command policies should emphasize the new Holistic Health and Fitness initiative that encourages regular aerobic and muscle-strengthening physical activity for soldiers.
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