Home equipment does not always get used continuously. Holidays, house moves, a broken machine or a delayed delivery can interrupt training for weeks. Two meta-analyses give a research-based picture of what happens to strength and muscle size when resistance training stops. This guide summarises the abstracts of a 2013 meta-analysis by Bosquet and colleagues in the Scandinavian Journal of Medicine and Science in Sports and a 2022 meta-analysis by Grgic in the International Journal of Environmental Research and Public Health. It is general information, not medical advice.
The 2013 meta-analysis on strength
Bosquet and colleagues searched seven databases and found 103 of 284 potential studies that met their criteria. They used training status, sex, age and the duration of training cessation as moderators, and calculated a standardised mean difference (SMD) in muscular performance with 95% confidence intervals. The results indicated a detrimental effect of stopping resistance training on all components of muscular performance:
- Submaximal strength: SMD −0.62 (95% CI −0.80 to −0.45).
- Maximal force: SMD −0.46 (95% CI −0.54 to −0.37).
- Maximal power: SMD −0.20 (95% CI −0.28 to −0.13).
The authors identified a dose-response relationship between the size of the effect and the duration of training cessation, so longer breaks were associated with larger losses. They also found that the effect was larger in older people, those over 65, and that for maximal force and maximal power it was larger in inactive people than in recreational athletes.
What the numbers mean in practice
The abstract reports standardised effects rather than pounds or kilograms, so it cannot be used to predict that a particular lifter will lose a specific amount in a given number of weeks. What it does show is direction and pattern: all three components declined, maximal power fell least, and the effect grew with time away. For maximal force and power, recreational athletes lost less than inactive people. The effect sizes are pooled averages across 103 studies with different designs, so an individual’s experience can differ.
The 2022 meta-analysis on muscle size in older adults
Grgic’s review searched five databases and included six studies with eight groups of older adults, with training interventions lasting 9 to 24 weeks and detraining periods from 12 to 52 weeks. Studies were rated fair or good on the PEDro checklist. Training increased muscle size significantly (Cohen’s d 0.99; 95% CI 0.63 to 1.36), and training cessation was followed by a significant decrease (d −0.83; 95% CI −1.30 to −0.36). In subgroup analyses, there was no significant decrease in muscle size after 12 to 24 weeks of cessation (d −0.60; 95% CI −1.21 to 0.01), but there was a significant decrease after 31 to 52 weeks (d −1.11; 95% CI −1.75 to −0.47). The author concludes that loss of muscle size might be related to detraining duration, and that future studies are needed to establish the time course of the changes.
Limits of the evidence
The two reviews address different outcomes and populations, so their findings should not be merged. The 2022 review is specific to older adults, involved only six studies and reports muscle size, not strength. The 2013 review covered strength and power across ages, but its abstract reports averages rather than a schedule of expected loss. Neither abstract addresses how quickly strength returns once training resumes, so no claim about regaining strength should be drawn from them. The results also concern complete cessation of resistance training, not reduced training or substituting other exercise.
Planning around interruptions
The practical takeaway from the evidence is modest: longer breaks were associated with larger declines, so shorter interruptions carry a smaller expected effect. Where a machine is out of action, the reviews do not say whether alternative equipment offsets the loss. For maintaining equipment so that interruptions are shorter, see our guide to the inspection routine for home equipment and our article on sourcing spare parts.
Frequently asked questions
Does strength always fall when training stops? The 2013 meta-analysis found a detrimental effect on submaximal strength, maximal force and maximal power, with larger effects for longer cessation.
Who loses most? The authors report larger effects in people over 65 and, for maximal force and power, in inactive people compared with recreational athletes.
Does muscle size fall after a short break? In older adults, the 2022 review found no significant decrease after 12 to 24 weeks but a significant one after 31 to 52 weeks.
The bottom line
Meta-analyses find that stopping resistance training lowers strength and power, with the effect increasing with the length of the break and being larger in older and inactive people. Muscle size in older adults did not fall significantly after 12 to 24 weeks but did after 31 to 52 weeks. The evidence describes the direction of the effect, not a precise schedule, and does not address how quickly strength returns.
Sources
- Bosquet L et al., “Effect of training cessation on muscular performance: a meta-analysis,” Scandinavian Journal of Medicine & Science in Sports, 2013
- Grgic J, “Use It or Lose It? A Meta-Analysis on the Effects of Resistance Training Cessation (Detraining) on Muscle Size in Older Adults,” International Journal of Environmental Research and Public Health, 2022