 This systematic review and meta-analysis aim to evaluate the effects of long-term supervised exercise on estimates of lower extremity bone strength from childhood to older age. The study included 10 randomized controlled trials that assessed the effects of exercise training on whole bone strength. The results showed a small and significant exercise effect among pre- and early pubertal boys, but not among pubertal girls, adolescent boys, adolescent girls, pre-menopausal women, or post-menopausal women. Evidence from per-protocol analyses of individual trials in children and adolescents indicated that programs incorporating regular weight-bearing exercise can result in 1% to 8% improvements in bone strength at loaded skeletal sites. In pre-menopausal women with high exercise compliance, improvements ranging from 0.5% to 2.5% have been reported. The study highlights the need for further well-designed, long-term randomized controlled trials with adequate sample sizes to quantify the effects of exercise on whole bone strength and its structural determinants throughout life.