Nine articles on eight original interventions (649 participants, range 11 to 147) were included; six were RCTs and the others were controlled trials. Methodological quality scores ranged from 29% to 100% and three of the eight studies scored better than 50%. Two RCTs did not conceal randomisation; common methodological flaws included lack of reporting of point estimates, lack of blinding the outcome assessor and lack of an intention-to-treat analysis.
Bone mass density was significantly increased in most of the resistance-training interventions. Only one trial (90 participants) reported a significant difference in favour of exercise compared with the control for bone mass density of the femoral neck. Although not statistically significant, exercise groups in seven out of the eight trials lost less bone mass density than the control groups.
Drop-out rates and attendance were reported in four of the eight trials. Where reported the average rate of drop-out was 3.3% (6.8% for exercise and 2.1% for control groups).
Two studies reported on adverse events and withdrawals. No serious or adverse events were reported but one study reported exacerbations of existing injuries in seven participants and three inguinal hernias were documented. Reasons for withdrawal from the other study were diverse and it was unclear whether they were related to the programme.