High-intensity (≥70% 1RM) vs low-to-moderate-intensity (<70% 1RM) resistance training in adults aged 50+: heavier training raised leg-press (SMD 0.95) and leg-extension strength (SMD 0.63) more, with no significant difference in lumbar-spine or femoral-neck BMD, falls or adverse events
Meta-analysis of 18 RCTs, 1283 participants
A systematic review and meta-analysis of RCTs comparing resistance training at ≥70% 1RM with training below 70% 1RM in adults aged 50 and over, for lower-limb strength, lumbar-spine and femoral-neck BMD, falls and adverse events. Content from the abstract only.
Participants
18 studies, 1283 participants, older adults (age ≥50 years).
Protocol
High-intensity (≥70% 1RM) vs low-to-moderate-intensity (<70% 1RM) resistance training. Primary outcomes: leg press and leg extension strength, lumbar-spine BMD, femoral-neck BMD; secondary: fall incidence and adverse events. SMDs and risk ratios pooled with a random-effects model.
Key Results
Leg press: SMD 0.95 (95% CI 0.48-1.43) in favour of high intensity.
Leg extension: SMD 0.63 (95% CI 0.09-1.17) in favour of high intensity.
No significant difference between regimens for BMD at the lumbar spine (SMD 0.28, 95% CI from -0.02 to 0.58) or at the femoral neck (SMD 0.13, 95% CI from -0.08 to 0.33).
Falls RR 2.68 (95% CI 0.65-11.11); adverse events RR 2.42 (95% CI 0.66-8.88) — no significant difference, but the intervals are wide.
Authors' conclusion: high intensity outperforms low-to-moderate intensity for lower-limb strength; the two appear similarly effective in maintaining BMD, with similar safety profiles.
Practical Application
"I'm over 50 — should I lift heavy or keep it light?" In a meta-analysis of 18 RCTs (1283 adults aged 50+), loads of 70% 1RM and above built more leg strength than lighter loads (leg press SMD 0.95), with no significant difference in falls or adverse events; bone density did not differ between the two intensities.
Do not promise that heavy lifting improves bone more than lighter lifting — in this analysis it did not, significantly. Not from this paper: cyclists' low bone loading is described in REF-522.
The falls and adverse-event intervals are wide (upper bounds above 8 and 11): "no significant difference" here means not shown to be worse, not proven equal. Technique and progression still matter.
Limitations
General older adults (≥50), not athletes; trial populations, durations and training protocols are not detailed in the abstract.
Heterogeneity, risk of bias and certainty of evidence are not reported in the abstract.
BMD comparison is between two active interventions; it says nothing about lifting vs not lifting.
Wide confidence intervals for falls and adverse events.
How this entry was checked and changed
Why this level
SR/MA of controlled trials; heterogeneity and trial quality are not reported in the abstract