High-intensity functional training (HIFT) aims to elicit gains across multiple fitness domains through cardiovascular and muscular improvements utilizing a general physical preparedness (GPP) program (versus specific training) done at relative high intensity. Little research exists to support whether HIFT improves specific fitness domains.
PURPOSE: This study examined the effect of HIFT through CrossFit on strength gains after 6 months (M).
METHODS: : Participants included 37 adults (46% women) ages 18-66 (mean age=31.413.1yrs) who were participating in a program evaluation study. Participants indicated previous HIFT experience, which was dichotomized as <6M (n=18), or 6M (n=19). Participants indicated previous HIFT experience. Strength was assessed by 1-repetition maximum (RM) lifts for the overhead press (P), back squat (S), and deadlift (D) using a standardized full-body warm-up and standard repetition progressions at baseline (B) and 6M. Paired samples T-tests were used to examine differences over time for each lift accounting for both experience and sex.
RESULTS: Both men and women saw significant strength improvements from B to 6M. Women saw significant improvements in all three lifts in both experience categories. Differences for women with <6M HIFT experience were increases in P (t=3.3, p=.017), S (t=2.6, p=.046), and D (t=2.5, p=.049), and those with 6M HIFT experience were increases in P (t=3.2, p=.013), S (t=3.4, p=.008), and D (t=2.5, p=.033). Men with <6M HIFT experience saw significant improvement with an increase in S (t=2.9, p=.017) only, while those with 6M HIFT experience saw significant improvement with increases in S (t=3.3, p=.011) and D (t=3.5, p=.008)
CONCLUSIONS: HIFT, while incorporating a GPP model, elicited strength improvements in both men and women, novice and experienced alike, with women seeing the greatest number of improvements. The marked number of strength improvements seen in most participants engaging in HIFT could be due to greater neuromuscular recruitment as a result of a constantly varied fitness program. More research is needed to determine the effects of HIFT on other measurable fitness domains.