AUTHOR=Cao Meng , Yang Baiquan , Tang Yucheng , Wang Chun , Yin Lijun 

TITLE=Effects of low-volume functional and running high-intensity interval training on physical fitness in young adults with overweight/obesity

JOURNAL=Frontiers in Physiology

VOLUME=15

YEAR=2024

URL=https://www.frontiersin.org/journals/physiology/articles/10.3389/fphys.2024.1325403

DOI=10.3389/fphys.2024.1325403

ISSN=1664-042X

ABSTRACT=<p><bold>Objectives:</bold> This study examined and compared the effects of functional and running high-intensity interval training (HIIT) on body composition, cardiorespiratory fitness, and muscular fitness of young adults with overweight or obesity.</p><p><bold>Methods:</bold> Forty-five participants (22.1 ± 2.1 years, BMI = 25.2 ± 1.0 kg/m<sup>2</sup>) were assigned to functional HIIT (HIIT-F; <italic>n</italic> = 15), running HIIT (HIIT-R; <italic>n</italic> = 15), or non-training control group (CON; <italic>n</italic> = 15). Participants in HIIT-F and HIIT-R performed functional exercise based-HIIT (four sets of all-out whole-body exercises including jumping jacks, squats, twist jumps and mountain climbers, et al.) and running HIIT (four sets of running on a treadmill) for 12 weeks, respectively. Body composition, muscular fitness, and cardiorespiratory fitness were assessed pre and post intervention.</p><p><bold>Results:</bold> Both HIIT-F and HIIT-R significantly improved the body composition and cardiorespiratory fitness, with HIIT-F induced greater improvements in lean mass (+1.623 vs. −1.034 kg, <italic>p</italic> &lt; 0.001), back strength (+6.007 vs. +3.333 kg, <italic>p</italic> &lt; 0.01), and push-ups (+5.692 vs. 1.923 reps, <italic>p</italic> &lt; 0.001) than that in HIIT-R. HIIT-R reduced more visceral fat area (VFA) (−11.416 vs. −4.338 cm<sup>2</sup>, <italic>p</italic> = 0.052) and induced similar improvement in cardiorespiratory fitness (VO<sub>2max</sub>, +2.192 vs. +2.885 mL/kg/min, <italic>p</italic> = 0.792) with HIIT-F.</p><p><bold>Conclusion:</bold> Twelve weeks of HIIT-R or HIIT-F improved physical fitness among young adults with overweight or obesity. Despite the similar impact on cardiorespiratory fitness, HIIT-F generates a better positive effect on muscular fitness relative to HIIT-R, which could be partly explained by the greater increase in lean mass after HIIT-F intervention.</p>