Detraining
Calculator.
Back after vacation, a busy month or a cold? Find a sensible starting weight and a short ramp back to where you were.
The weight of your working sets before the break, e.g. on squats.
A cautious rule of thumb, not medical advice. Everything is calculated in your browser — nothing is stored or sent.
reppd keeps your whole training history — every set and every working weight — so after a break you know exactly where you left off.
How much strength do you lose during a break?
Less than most people fear. A review of elite rugby and American football players found that strength was maintained for up to about 3 weeks without training; after that it declined faster, by about 14.5% on average over a mean break of roughly 7 weeks (McMaster et al., 2013). Endurance tends to fade faster: in a classic small study, VO2max dropped 7% within the first 21 days off (Coyle et al., 1984).
And what you lose tends to come back quickly. In one small study, young men who took 3-week breaks after every 6 weeks of bench press training ended up with similar muscle and strength gains after 24 weeks as a group that trained straight through (Ogasawara et al., 2013).
How does the calculator work?
It uses a simple, deliberately cautious rule model: lower the weight a little, then climb back over a few sessions.
| Days without training | Session 1 | Back at 100% in |
|---|---|---|
| under 10 | 100% | — |
| 10–20 | 95% | session 2 |
| 21–42 | 90% | session 3 |
| 43–90 | 85% | session 4 |
| over 90 | 80% | session 5 |
If you were sick, or you are 50 or older, the calculator moves one stage more cautious (both together: two stages). Weights are rounded down to a loadable step. These numbers are a practical rule of thumb derived from the research above, not values from a single study.
Coming back after being sick
If you had a fever or symptoms below the neck in the last 48 hours, skip training for now. When you do return, keep the first session easy. If symptoms come back during training or you are unsure, get medical advice first.
Planning a break? Keep it light, keep it heavy
If you can squeeze in a little training, a narrative review found that strength and muscle size (at least in younger people) were maintained for up to 32 weeks with as little as one session per week and one set per exercise — as long as the load stayed heavy. Older adults may need up to two sessions per week with 2–3 sets (Spiering et al., 2021).
More on this in our guide: Training after a break — what 1, 3 and 8 weeks off really cost.