Katie M. Heinrich

High-intensity functional training (HIFT) is an exercise modality that emphasizes functional, multi-joint movements that can be modified to any fitness level and elicit greater muscle recruitment than more traditional exercise. As a relatively new training modality, HIFT is often compared to high-intensity interval training (HIIT), yet the two are distinct. HIIT exercise is characterized by relatively short bursts of repeated vigorous activity, interspersed by periods of rest or low-intensity exercise for recovery, while HIFT utilizes constantly varied functional exercises and various activity durations that may or may not incorporate rest. Over the last decade, studies evaluating the effectiveness of HIIT programs have documented improvements in metabolic and cardiorespiratory adaptations; however, less is known about the effects of HIFT. The purpose of this manuscript is to provide a working definition of HIFT and review the available literature regarding its use to improve metabolic and cardiorespiratory adaptations in strength and conditioning programs among various populations. Additionally, we aim to create a definition that is used in future publications to evaluate more effectively the future impact of this type of training on health and fitness outcomes.

BACKGROUND: Understanding exercise participation for overweight and obese adults is critical for preventing comorbid conditions. Group-based high-intensity functional training (HIFT) provides time-efficient aerobic and resistance exercise at self-selected intensity levels which can increase adherence; behavioral responses to HIFT are unknown. This study examined effects of HIFT as compared to moderate-intensity aerobic and resistance training (ART) on exercise initiation, enjoyment, adherence, and intentions. METHODS: A stratified, randomized two-group pre-test posttest intervention was conducted for eight weeks in 2012 with analysis in 2013. Participants (n = 23) were stratified by median age (< or ≥ 28) and body mass index (BMI; < or ≥ 30.5). Participants were physically inactive with an average BMI of 31.1 ± 3.5 kg/m2, body fat percentage of 42.0 ± 7.4%, weight of 89.5 ± 14.2 kg, and ages 26.8 ± 5.9 years. Most participants were white, college educated, female, and married/engaged. Both groups completed 3 training sessions per week. The ART group completed 50 minutes of moderate aerobic exercise each session and full-body resistance training on two sessions per week. The HIFT group completed 60-minute sessions of CrossFit™ with actual workouts ranging from 5-30 minutes. Participants completed baseline and posttest questionnaires indicating reasons for exercise initiation (baseline), exercise enjoyment, and exercise intentions (posttest). Adherence was defined as completing 90% of exercise sessions. Daily workout times were recorded. RESULTS: Participants provided mostly intrinsic reasons for exercise initiation. Eighteen participants adhered (ART = 9, 81.8%; HIFT = 9, 75%). HIFT dropouts (p = .012) and ART participants (p = .009) reported lower baseline exercise enjoyment than HIFT participants, although ART participants improved enjoyment at posttest (p = .005). More HIFT participants planned to continue the same exercise than ART participants (p = .002). No significant changes in BMI or body composition were found. Workouts were shorter for HIFT than ART (p < .001). CONCLUSIONS: HIFT participants spent significantly less time exercising per week, yet were able to maintain exercise enjoyment and were more likely to intend to continue. High-intensity exercise options should be included in public health interventions. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: http://NCT02185872. Registered 9 July 2014.

BACKGROUND: Parks are key community assets for physical activity, but some evidence suggests these resources are not equitably distributed. PURPOSE: This study examined disparities by income and race/ethnicity in the availability, features, and quality of parks across Kansas City, Missouri. METHODS: All parks and census tracts (CTs) were mapped using geographical information systems, and park features and quality were determined via audits. Multivariate analyses of covariance analyzed differences in park availability, features, and quality across low-, medium-, and high-income and race/ethnicity CT tertiles. RESULTS: Low-income CTs contained significantly more parks, but also had fewer parks with playgrounds and more quality concerns per park. High minority CTs had more parks with basketball courts, but fewer parks with trails. Medium-income CTs contained more aesthetic features per park. CONCLUSIONS: Future research should examine policies that contribute to and that might rectify disparities in park features and quality, especially in low-income and high minority areas.

Appropriate and effective physical fitness training is imperative for soldier survival and mission success. The purpose of this study was to determine the effects of Mission Essential Fitness (MEF) circuit-style training program compared to standard Army Physical Readiness Training (APRT) on fitness, physiological, and body composition changes. Active duty Army personnel were randomly assigned to two groups (MEF = 34 or APRT = 33) for 8 weeks of training (15 sessions each). The MEF program included functional movements focused on strength, power, speed, and agility. Fifteen exercises were performed continuously for 60 to 90 seconds for 45 minutes. Baseline and post-test measures included the Army physical fitness test, physiological indicators, body composition, and additional fitness indicators. One-way analysis of covariance models indicated that MEF participants significantly increased their push-ups (p = 0.033), bench press (p = 0.001), and flexibility (p = 0.003) and significantly decreased their 2-mile run (p = 0.003) and step test heart rate (p = 0.004) compared to participants doing APRT. Both groups maintained body composition (p > 0.05) and reported no injuries. The MEF training program safely improved muscular strength and endurance, cardiovascular endurance, and flexibility, supporting functional fitness circuit-style exercise training for military personnel.

Obesity, physical activity, and sedentary behavior in childhood are important indicators of present and future health and are associated with school-related outcomes such as academic achievement, behavior, peer relationships, and self-esteem. Using logistic regression models that controlled for gender, age, ethnicity/race, and socioeconomic status, we investigated the likelihood that youth with learning disabilities (LD) and attention-deficit/hyperactivity disorder (ADHD) are obese, physically active, and sedentary using a nationally representative sample of 45,897 youth in the United States from 10 to 17 years of age. Results indicated that youth with comorbid LD/ADHD were significantly more likely than peers without LD or ADHD to be obese; that youth with LD only, ADHD only, and comorbid LD/ADHD were significantly less likely to meet recommended levels of physical activity; and that youth with LD only were significantly more likely to exceed recommended levels of sedentary behavior. Medication status mediated outcomes for youth with ADHD. We offer school-based recommendations for improving health-related outcomes for students with LD and ADHD.