What did Borde et al. (2015) find?

Key numbers

Who was studied and how the review was done

Resistance training is often used to build strength and muscle in later life, but before this review it was unclear how specific training variables related to the size of the gains in healthy older adults.

The authors searched PubMed, Web of Science and The Cochrane Library from January 1984 up to June 2015. They included only randomized controlled trials of resistance training in adults with a mean age of 65 and older that measured strength or muscle size and described the training. The search found 506 studies, and 25 were eligible.

The main outcomes were the heaviest weight a person could lift once (one-repetition maximum), maximal force against a fixed resistance (isometric maximum voluntary contraction), and muscle size measured as cross-sectional area, volume or thickness. Each trial's training group was compared with its control group as a standardized mean difference, an effect size. Study quality was rated on the PEDro scale.

What the review found

Resistance training improved strength substantially (1.57 across 25 studies) and had a small effect on muscle size (0.42 across nine studies). The effect on one-lift strength was large for both the upper body (1.61 across 11 studies) and the legs (1.76 across 19 studies). The effect on maximal leg force against a fixed resistance was medium (0.76 across four studies).

A meta-regression then asked which training features explained the differences between trials. Training period (p equals 0.04), intensity (p less than 0.01) and total time under tension (p less than 0.01) were significantly related to strength gains. Rest between sets showed a trend (p equals 0.06).

Training features linked to the largest strength gains

Looking at one feature at a time, the largest strength effects were seen with the longest training periods, 50 to 53 weeks (2.34), and with loads of 70 to 79 percent of one-repetition maximum (1.89). Two sessions per week (2.13), two to three sets per exercise (2.99) and seven to nine repetitions per set (1.98) were also linked to greater gains. So were a total time under tension of 6.0 seconds (3.61) and sixty seconds of rest between sets (4.68, from only two studies).

These figures compare groups of trials. The review identified dose-response relationships associated with greater gains, not settings proven to give the best result for everyone, and differences between the trials' programs and their quality limit any claim of a single best dose.

What this does not show

The review measured strength and muscle size in the lab, not daily function. It did not test any Systematic assessment or set its red, yellow and green standards, which are Systematic's own.

The evidence

Each cited source is labeled according to how it supports the particular claim on this page. Direct test evidence, underlying-capacity findings and population reference values are distinguished from Systematic-defined protocols and standards. Historical development notes are retained internally rather than presented as public evidence. A study of an underlying capacity is never presented as validation of the Systematic test itself.

• Underlying-capacity evidence New source

  Borde et al. (2015). Dose-Response Relationships of Resistance Training in Healthy Old Adults: A Systematic Review and Meta-Analysis. Sports medicine (Auckland, N.Z.).

  What it found. In 25 randomized trials in adults with a mean age of 65 and older, resistance training improved strength substantially (1.57) and had a small effect on muscle size (0.42). Some training features were associated with greater gains.

  What it does not show. It does not show a single best dose for everyone, did not measure daily function, and did not test or set any Systematic standard.

  PubMed 26420238