Different Training Durations and Frequencies of Tai Chi for Bone Mineral Density Improvement: A Systematic Review and Meta-Analysis

Table 2

Subgroup analyses between the Tai Chi and the nonexercise group for the outcome BMD change in the lumbar spine (L2–L4) according to intervention durations and frequencies.

Subgroup	n	SMD, 95% CI		Heterogeneity
Intervention duration
≤10 months	8	0.38, 95% [0.04, 0.71]	0.03	I^2 = 66%,  = 0.005
>10 months	10	0.50, 95% [0.13, 0.86]	0.008	I^2 = 78%,  < 0.00001
Intervention frequencies
≤4 days/week	9	0.16, 95% [−0.02, 0.35]	0.09	I^2 = 0%,  = 0.97
>days/week	9	0.67, 95% [0.25, 1.09]	0.002	I^2 = 84%,  < 0.00001