The Army Combat Fitness Test (ACFT) and the Health of the Active Component: Understanding the Link Between the ACFT and Personnel Health and Injuries

The research reported here was completed in December 2023, followed by security review by the sponsor and the U.S. Army Office of the Chief of Public Affairs, with final sign-off in January 2025.

The Army Combat Fitness Test (ACFT) became the U.S. Army's physical fitness test of record in October 2022. The test consists of six events intended to measure muscular strength and endurance, power, speed, agility, aerobic endurance, balance, flexibility, coordination, and reaction time. One of the Army's stated goals for the test was to reduce injuries. More than half of soldiers experience a new injury in 2021, so success in reducing the risk of injury could have a significant impact on both medical costs and lost workdays. Because the ACFT has been administered for a relatively short period, there are limited data available to assess the relationship between the ACFT and soldier health and injuries. Nevertheless, this research effort used available data to gain initial insights into this relationship. This study was part of RAND's ongoing independent assessment of the ACFT, focusing specifically on injury risk.

To determine the empirical relationship between the ACFT and injuries, we reviewed the literature on the associations between fitness testing and injury rates, as well as existing surveillance systems and information. We also combined the Army's ACFT data on physical fitness performance with data from the Defense Health Agency on medical encounters and examined reported injury rates for the active component of the Army during periods when the Army Physical Fitness Test (APFT) was still in place, as well as during the rollout and full implementation of the ACFT. Most of our statistical analyses use tests collected after April 1, 2022, because the ACFTs recorded after this date are most representative of the state of current ACFT policies.

Key Findings

Looking across the varied analyses conducted, which included aggregate analysis of the Army as a whole and the injury and ACFT administration experiences of individual soldiers, we highlight eight key findings:

• The timing of ACFT administration is strongly associated with injury risk. Our data showed an increase in overuse injuries prior to the test date but no change in the rate of acute trauma injuries leading up to the test. This pattern could reflect changes in the frequency or intensity of training as soldiers prepare for the ACFT, but it also may reflect some set of soldiers proactively choosing to seek care for existing nagging injuries or seeking a permanent profile prior to taking the test.
• Acute trauma and overuse injuries are a risk the day of the test. We observed a brief spike in injuries on the date of the test and for several days into the 180-day window following the test date, which are likely to be injuries associated with the ACFT itself.
• Risk of injury from the test appears to decline with experience. The ACFT is new, and learning to train for and take new physical fitness assessments should be expected to carry some degree of injury risk that can attenuate over time. We observed a decline in injury incidence associated with a soldier gaining experience with the test.
• The ACFT does not present a substantially greater injury risk than the APFT. We compared injury rates six months before and after the ACFT with similar windows surrounding APFT tests and found that the pattern of observed injury for the ACFT was similar to that of the APFT.
• Soldiers delay treatment when health care is harder to get. We observed injury patterns that suggest that soldiers are likely delaying treatment (or that they face unavoidable delays from lack of health care access) for injuries when the test is run on Friday or Saturday relative to early in the week.
• Injury risks for male and female soldiers differ by body region. We observed some differences in location of injury by gender that warrant continued observation and may be targets for intervention. For both overuse and acute trauma injuries, women are significantly more likely to suffer lower-extremity injuries than their male counterparts, whereas men are correspondingly more likely to suffer upper-extremity injuries.
• Overall ACFT performance is predictive of future injury risk. Soldiers who failed the ACFT were about 20 percent more likely to suffer an injury in the 180-day window following the ACFT. In contrast, soldiers who scored higher on the ACFT overall had significantly lower risk of any injury even when compared with the group that received “narrowly passing” total scores on the ACFT (360–419). This pattern is driven mostly by cumulative microtrauma (or overuse) risk, although acute trauma risk is also associated with performance. Ultimately, better performance on the ACFT is associated with reduced risk of injury.
• Most of the test components of the ACFT also show strong associations with future injury risk when considered individually. Consistent with prior research, cardiorespiratory activities exhibited some of the strongest positive associations between performance and reduced injury risk. In general, the patterns found for the overall ACFT held (i.e., event failure was associated with a higher risk of injury, whereas better event performance was associated with lower risk of overuse injury). Some high-performance outcomes on events were linked to elevated risk. For example, among some soldiers, performance at the highest scoring tiers for 3 Repetition Maximum Deadlift, Sprint-Drag-Carry, and Standing Power Throw was associated with higher acute trauma risk.

To the extent that broader, more-holistic training is indeed motivated by the more-expansive physical requirements of the ACFT, the literature suggests that the ACFT could in the long term lead to an overall reduction in injury rates. Further monitoring of injuries, especially compiled with information on actual training programs, would bolster this conclusion.

Recommendations

Drawing on the findings of our analytical work and review of prior research literature, we offer the following recommendations, many of which focus on enhancing surveillance, data collection, and monitoring so that the Army has the information needed to make evidence-based decisions regarding future aspects of the ACFT:

• Include additional relevant determinants of injury risk in surveillance and monitoring systems. Demographic, occupational, and physical characteristics provide useful information about injury risk and injury associated with physical fitness training and assessments. Collecting this information in one place, in a time series for all relevant factors, will enable more fidelity in Army analysis of health and injury rates across installations and over time.
• Enhance existing or establish new procedures to collect cause-of-injury data. Information relating to the cause and setting for injuries is not consistently recorded but should at a minimum be collected alongside ACFT data at the time of the test, including instances in which soldiers fail the tests because of injury during one of the events. The location of the test, the weather, and other factors could also be collected during physical fitness assessments to help rigorously assess their influence on injury risk and performance. Similar data could also be collected on profiles issued as a result of injury.
• Incorporate physical fitness assessments into injury surveillance. ACFT scores have substantial predictive power in assessing an individual soldier's risk of injury. Including information on fitness performance (i.e., ACFT scores) in injury surveillance systems, and even in medical records, could be used as an early warning sign for risk. At a minimum, ACFT failures could be used to aid in targeting soldiers at risk potentially through resources from the broader Army fitness operating concept, Holistic Health and Fitness, where available.
• Monitor ACFT performance throughout the performance range; do not focus only on those who do not pass. Injury risk tends to be substantially higher for soldiers who fail any ACFT component. Yet acute trauma is also higher among male and female soldiers who are among the highest performers on some strength tests. Further assessments should be conducted to better understand this risk among high performers to ensure that standards are not set in ways that incentivize training and test-taking habits that induce excessive risk.
• Continue to monitor injury risk and track trends. Our analysis suggests that injury risk falls with experience taking the ACFT. This means that the overall injury risk associated with taking the ACFT during the periods we examined may continue to evolve. At the same time, as the stakes of the test increase for personnel actions, soldiers may be motivated to seek higher levels of performance in ways that increases risk. Continued monitoring of trends in injury risk and in the types of injuries incurred will help target areas in which potential intervention is needed.
• Continue to systematically collect data on desired outcomes from investments such as Holistic Health and Fitness. This program has not been in place long enough or implemented in a way for us to rigorously assess its impact on injuries with the data available during our study. But our literature review suggests that investments in this multidimensional initiative could have an impact on injury rates. The Army should seek service-wide evidence and assess information on each of the dimensions of Holistic Health and Fitness to evaluate the success of this program as it is rolled out and use this information to make evidence-based decisions on implementation timing and future investments.