Physiological comparison between competitive and beginner high intensity functional training athletes

Introduction: Among high intensity trainings, high intensity functional training (HIFT) represent one of the most recent developments. The aim of the present study was to investigate the differences between a group of competitive (CMP) HIFT athletes and a group of age- and gender-matched beginner (BGN) HIFT athletes, to clarify the physiological characteristics of each group and the reasons for differences. Methods: 10 BGN (32.5 ± 6.2 years) and 10 CMP (29.0 ± 5.4 years) athletes, were included in the study and were evaluated for anthropometry, VO2peak, lactate threshold, isometric and isokinetic leg maximal power and strength, handgrip and maximal anaerobic power. Results: Compared to BGN athletes, CMP reached higher levels of VO2peak (56.1 ± 2.89 ml·kg-1·min-1 CMP vs. 46.5 ± 6.86 ml·kg-1·min-1 BGN; p < .001), lower limb maximal power (4.5 ± 0.42 W·kg-1 CMP vs. 2.9 ± 0.67 W·kg-1 BGN; p < .001), maximal handgrip strength (61.1 ± 8.20 N·kg-1 CMP vs. 45.1 ± 7.58 N·kg-1 BGN; p < .001), maximal knee extension isometric strength (11.7 ± 1.43 N·kg-1 CMP vs. 9.1 ± 2.00 N·kg-1 BGN; p < .05), isokinetic strength (281.3 ± 28.18 N·kg-1 CMP vs. 234.6 ± 26.15 N·kg-1 BGN; p < .05) and anaerobic peak power (639.1 ± 125.54 W·kg-1 CMP vs. 442.7 ± 155.96 W· kg-1 BGN; p > .006), while anaerobic capacity did not show significant differences (101.8 ± 9.33 kJ CMP vs. 87.0 ± 28.37 kJ BGN; p = .1). Conclusions: CMP athletes showed greater physiological adaptations in aerobic fitness and strength than BGN. Differences may be attributed to the technical skills acquired by CMP and not only to the physiological adaptations induced by the specific training. The lack of differences in anaerobic capacity is likely due to an early and fast improvement in BGN, compared to other parameters.