Army Training at High Intensity Study

Although soldiers must be ready to respond to occupational and war theatre demands at a moment's notice, there is an epidemic of overweight and obesity and a need for improved fitness and health in the military. Using a cluster randomized clinical trial we propose to test the effectiveness of a High-Intensity Functional Training (HIFT) exercise intervention to improve the body composition and fitness of active duty military personnel. The effectiveness of the HIFT intervention will be compared to usual Army Physical Readiness Training. Main outcomes will include changes in body composition and traditional fitness measures, a test of combat-preparation, and measures of cardiovascular health risk for both groups.

We will examine the effectiveness of a high-intensity functional training (HIFT) exercise intervention compared to Army Physical Readiness Training (APRT) and their related dietary instructions in improving body composition (percent body fat \[%BF\], fat mass, lean body mass, weight) and domains of Total Force Fitness (TFF; Army Physical Fitness Test \[APFT\], aerobic capacity, power, strength, and combat preparation and readiness) in a 6-month cluster-randomized clinical trial (CRCT) with 2 (+/- 1) month follow-up. We also will examine the effects of both exercise programs on cardiovascular disease (CVD) health risk (resting heart rate, blood pressure). We will conduct assessments at baseline, 6-months, and 2-month follow-up (+/- 1 month). We also will assess training time/volume, injuries, adverse events, adherence, and participant satisfaction and account for demographic and psychosocial variables.

In our CRCT, we aim to recruit and randomize approximately 150 soldiers (n=15 clusters-staff groups/platoons-per condition with at least 5 soldiers nested within each cluster) comparing the effectiveness of HIFT versus usual care (APRT) on:

Specific Aim 1 - changes in body composition including: percent body fat (%BF), fat mass, fat free mass, and body weight.

We hypothesize that soldiers in the HIFT condition will be significantly more likely to decrease a. %BF and b. fat mass, and to increase c. fat free mass than those in the APRT condition; we expect both groups to d. maintain body weight.

Specific Aim 2 - changes in fitness (e.g., APFT, power, strength), while accounting for actual physical training time in each condition.

We hypothesize that soldiers in the HIFT condition will have significantly greater improvement in their performance on fitness tests when compared to those in APRT, despite significantly less total training time. These outcomes will help determine if functional-oriented training can result in better fitness and combat preparedness for Army personnel.

Eligibility Criteria:
Inclusion Criteria:

* physical activity clearance to participate in the study via the Physical Activity Readiness Questionnaire;
* willingness to adhere to study protocol and complete all study assessments; and
* high likelihood of assignment to the military post over the 8 (+/-) 1-month course of the study.

Exclusion Criteria:

* being on permanent or temporary medical profile or having any medical condition or injury which would prevent participation in the exercise protocols;
* having a pacemaker or other implanted/internal electrical device;
* currently on administrative leave or assigned to exclusively administrative duties; and
* (if female) pregnant or lactating, or planning to become pregnant in the next 9-months.