IJERPH, Vol. 18, Pages 9648: The Efficacy of Brief School-Based Exercise Programs in Improving Pubertal Bone Mass and Physical Fitness: A Randomized Controlled Trial (International Journal of Environmental Research and Public Health)

Purpose: To examine the effects of three types of school-based exercises on bone health and physical fitness function in Chinese boys and girls. Methods: One hundred and seventy-four Chinese boys and girls were randomly assigned into four groups: (1) sham exercise (ShEx); (2) high-impact exercise (HiEx); (3) high-impact exercise with various directions (HiExVi); and (4) high-intensity interval exercise (HiInEx). Speed of sound (SOS) and physical fitness parameters were determined before and after six-month intervention. Results: At the end of six-month intervention, participants in all groups show an increment of SOS compared with the baseline (p < 0.05), and the changes were higher in HiEx (mean: 38.878 m/s, 95% CI: 32.885~44.872, p = 0.001) and HiExVi groups (49.317 m/s, 42.737~55.897, p < 0.001) compared with ShEx group (20.049 m/s, 13.751~26.346). Six-month exercise training generated a reduction of percent of body fat (PBF) and waist–hip ratio (WHR) (p < 0.05). The decrease of PBF was greater in HiExVi (âˆ`1.222%, âˆ`1.820~âˆ`0.624, p = 0.012) and HiInEx groups (âˆ`1.395%, âˆ`1.809~âˆ`0.982, p = 0.003), whereas the reduction of WHR was larger in HiEx (âˆ`0.026, âˆ`0.039~âˆ`0.014, p = 0.009), HiExVi (âˆ`0.024, âˆ`0.036~âˆ`0.012, p = 0.021), and HiInEx groups (âˆ`0.035, âˆ`0.046~âˆ`0.024, p < 0.001) compared with ShEx group. Balance function (BLF), vital capacity (VC), standing long jump (SLJ), and sit up (SU) increased in all intervention groups (p < 0.05). The BLF increased in HiEx (6.332 s, 4.136~8.528, p = 0.001), HiExVi (10.489 s, 8.934~12.045, p < 0.001), and HiInEx groups (9.103 s, 7.430~10.776, p < 0.001) showed a greater change than that of ShEx group (1.727 s, 0.684 ~2.770). The increment of VC (273.049 mL, 199.510~346.587, p < 0.001) and SU (2.537 times/min, 0.639~4.435, p = 0.017) was higher in HiInEx group, whereas the accrual in SLJ was larger in HiExVi (7.488 cm, 4.936~10.040, p = 0.007) compared with ShEx group (58.902 mL, 7.990 ~109.814; âˆ`0.463 times/min, âˆ`2.003~1.077; 1.488 cm, âˆ`0.654 ~3.630). Conclusion: The brief school-based exercises were effective in improving schoolchildren`s health, but they showed different effects, with HiEx mostly improving bone health, HiInEx largely benefiting physical fitness function, and HiExVi enhancing both bone and physical fitness.