Dreu White1, Derek A. Crawford1, Nicholas B. Drake1, Justin DeBlauw2, Michael J. Carper1, & Katie M. Heinrich2

1Pittsburg State University, Pittsburg, KS; 2Kansas State University, Manhattan, KS

High intensity functional training (HIFT) is a novel exercise intervention that may test body systems in a balanced and integrated fashion through challenging individuals’ abilities to complete mechanical work; however, research has not determined if work capacity (WC) is a unique measure of fitness. PURPOSE: To determine if change in WC is related to change in the underlying physiologic measures. METHODS: Twenty-five healthy men (n=13; age = 22.6±3.5; body mass = 86.1±13.9 kg; height = 182.8±8.1 cm) and women (n=12; age = 21.0±1.5; body mass = 70.5±11.3 kg; height = 165.6±5.7 cm) completed a six-week (5 days/week) HIFT intervention with WC and various physiologic measures of fitness assessed pre- and post-intervention. Physiologic variables assessed included aerobic capacity (VO2max); one-repetition maximums for back squat, shoulder press, and deadlift exercises; peak power and fatigue index from a 30-second Wingate bout; and WC (i.e., the maximal amount of mechanical work performed in a given time domain). RESULTS: At baseline, all physiologic measures of fitness were significantly associated with WC and this relationship was even stronger at post-intervention assessment (all p < 0.05). Further, there were significant improvements across these measures in response to the HIFT intervention (all p < 0.05). However, a multiple regression model using the change in these measures did not significantly predict the change in WC induced by HIFT (F = 0.330; Sum of Squares = 637.3; df = 5; p = 0.908; R2 = 0.141). In addition, no single measure of fitness was significantly associated with the change in WC (Table 1). CONCLUSION: HIFT may be a unique challenge to individuals’ fitness beyond traditional exercise programs; as evidenced by the independence of changes in WC from changes in the associated physiologic components. Elucidating the translational impact of increasing WC via HIFT may be of great interest to health and fitness practitioners.

White Table 1.docx (14 kB)
White Table 1

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