Exercise dosing to retain resistance training adaptations in young and older adults.
Level 2 - randomized trial
Individual randomized controlled trial comparing two reduced-dose maintenance protocols and complete detraining across two age cohorts.
PubMed 21131862 · doi:10.1249/MSS.0b013e318207c15d
What was done
Seventy adults in two age cohorts—young (20–35 years) and older (60–75 years)—completed a two-phase trial. Phase 1 consisted of progressive resistance training 3 days per week for 16 weeks. In Phase 2 (32 weeks), participants were randomly assigned to complete detraining, a one-third maintenance dose, or a one-ninth maintenance dose of Phase 1 training volume. Outcomes measured included muscle mass, myofiber size, myofiber-type distribution (IIx-to-IIa shift), and muscle strength.
What was found
The abstract reports no numerical values, percentages, or confidence intervals. Descriptively, Phase 1 induced gains in muscle mass, myofiber size, strength, and a shift from IIx to IIa myofiber types in all subjects. In Phase 2, both the one-third and one-ninth maintenance prescriptions preserved Phase 1 muscle hypertrophy in young adults (with the one-third dose eliciting further myofiber hypertrophy), but neither maintenance dose preserved muscle hypertrophy in older adults. Detraining reversed the IIx-to-IIa myofiber shift in both groups, while the one-third maintenance dose best preserved this shift. Phase 1 strength gains were largely retained throughout detraining in both age groups with only slight reductions at 32 weeks.
Why it matters
This study demonstrates that minimum exercise doses to preserve resistance training adaptations differ by age. While young adults can maintain muscle hypertrophy with substantially reduced weekly volume, older adults require a higher maintenance stimulus to prevent muscle loss, even though strength gains are relatively robust to detraining.
Limits
The abstract provides no raw numbers, effect sizes, standard deviations, or p-values. The sample of 70 participants was divided across two age brackets and three Phase 2 arms, resulting in relatively small subgroup sizes. The study only evaluated healthy older adults aged 60–75 and young adults aged 20–35, limiting generalizability to frail older populations or intermediate age groups.
Cited by
- supports In a study by Bickel and colleagues, young subjects who reduced resistance training volume from 27 sets per week on quads to 3 sets per week (one-ninth the volume) maintained most of their muscle size and strength for approximately six months.