Assessing The Feasibility And Characterizing The Energy Expenditure And Relative Intensity Of A High-intensity Functional Training Regimen For Obese Female Adults: A Feasibility Study

PURPOSE: To assess the feasibility and characterize the energy expenditure and relative intensity of participation of an obese cohort in a signature 35-minute group-based HIFT regimen. The demand for efficient and effective exercises has grown in concert with increased attention to fitness as a determinant of overall health, especially in the obese populations. While past studies have examined the benefits of traditional conditioning exercises, there have been limited investigations of high intensity functional training (HIFT). METHODS: During the regimen, 12 obese female adults (body mass index (BMI): 33.7 + -1.9 kg/min2, 29.3 + -4.8 years) donned a portable breath-by-breath gas analyzer and a heart rate monitor. The session was led by a group instructor and consisted of 30, 1-minute rounds of work (i.e., 15 functional upper and lower body resistive exercises alternating with the last 15 seconds on an air bike) for a culmination of 35 minutes. RESULTS: Mean caloric expenditure (509 ± 79 kcal), maximum heart rate (173 ± 5 bpm), and metabolic equivalents (12.1 ± 1.4 kcal/kg/h) were characterized as a vigorous-intensity activity according to the Compendium of Physical Activities guidelines. The majority (92%) of participants reportedly enjoyed HIFT and would include it as part of a comprehensive weight-loss exercise program. CONCLUSIONS: These HIFT time-efficient workouts fulfill national exercise guidelines for weekly vigorous-intensity activities, as outlined by the Physical Activity Guidelines for Americans. Moreover, implementing this high energy expenditure session twice weekly may comport with Physical Activity Guidelines for Americans weekly physical activity recommendations. HIFT training may provide a feasible, safe, and time-efficient mode of exercise for those seeking weight loss.