High-intensity Interval Training Elicits Superior Benefits On Bone Metabolism In Sedentary Young Women

Abstract

PURPOSE: The objective of the present study was to investigate the effects of 8-week high-intensity interval training (HIIT) on bone metabolism in sedentary college women. METHODS: Twenty-six healthy, sedentary female participants were randomly assigned into either HIIT (n = 13, age 23.2 ± 2.9 yr, weight 59.2 ± 7.2 kg, height 162.9 ± 3.3 cm; 90% VO2max run for 3 min interspersed with 40% VO2max run for 2 min, 6 bouts in one session) or moderate-intensity continuous training (MICT) group (n = 13, age 21.9 ± 1.7 yr, weight 59.3 ± 6.6 kg, height 160.9 ± 4.4 cm; 60% VO2max continuous run for 30 min) with 3 sessions per week for 8 weeks. The bone mineral density (BMD), quantitative ultrasound of the calcaneus (CUS), serum bone turnover markers, jump abilities and body composition were measured pre and post HIIT and MICT interventions. RESULTS: After 8-week interventions, 1) The total body BMD (pre vs post: 0.94 ± 0.05 vs 1.01 ± 0.05, p < 0.01 in HIIT; 0.95 ± 0.05 vs 1.00 ± 0.05 g/cm2, p < 0.01 in MICT), lower limb BMD (1.01 ± 0.08 vs 1.06 ± 0.06, p < 0.01 in HIIT; 1.00 ± 0.08 vs 1.04 ± 0.10 g/cm2, p < 0.01 in MICT), pyridinoline (PYD) (29.93 ± 7.00 vs 25.42 ± 6.79, p < 0.01 in HIIT; 31.64 ± 6.22 vs 25.13 ± 5.39 nmol/L, p < 0.01 in MICT) and %body fat (31.43 ± 5.65 vs 28.85 ± 5.52, p < 0.01 in HIIT; 33.15 ± 4.48 vs 31.48 ± 4.73, p < 0.05 in MICT) were significantly changed without differences between two groups. 2) The 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) (12.10 ± 2.59 vs 17.19 ± 3.44, p < 0.01 in HIIT; 12.08 ± 2.11 vs 14.80 ± 2.01 ug/L, p < 0.01 in MICT), standing long jump (1.61 ± 0.78 vs 1.77 ± 0.83, p < 0.01 in HIIT; 1.59 ± 0.13 vs 1.65 ± 0.14 m, p < 0.01 in MICT) and vertical jump (2.30 ± 0.05 vs 2.42 ± 0.05, p < 0.01 in HIIT; 2.33 ± 0.04 vs 2.37 ± 0.04 m, p < 0.01 in MICT) were increased in both groups with significantly higher changes in HIIT group (p < 0.05). 3) The calcaneus stiffness index (CSTI) (108.77 ± 10.47 vs 126.38 ± 11.92 %, p < 0.01 in HIIT), calcaneus broadband ultrasound attenuation (CBUA) (121.70 ± 9.47 vs 140.40 ± 9.17 dB/MHz, p < 0.01 in HIIT) and osteocalcin (OC) only significantly increased after HIIT intervention (p < 0.01). CONCLUSIONS: It suggested that 8-week HIIT and MICT intervention could improve BMD and body composition. Compared with similar workload MICT, HIIT elicited superior benefits on bone formation and related jump abilities.