PLANNING · DETRAINING
Detraining Decay Estimator
Estimate 1RM loss across a layoff using Mujika's detraining model and your training age.
Result
1RM Decay Over Layoff
Predicted 1RM curve across the weeks-off window (Mujika exponential model).
Weekly trajectory
| Week | Predicted 1RM | % of peak |
|---|---|---|
| 0 | 150 kg | 100% |
| 1 | 148.9 kg | 99.3% |
| 2 | 147.8 kg | 98.5% |
| 3 | 146.7 kg | 97.8% |
| 4 | 145.7 kg | 97.1% |
How to use it
- Open Detraining Decay Estimator and enter your current baseline accurately.
- Adjust one variable at a time so changes are easy to interpret.
- Review the headline output first, then inspect supporting metrics.
- Run at least one conservative and one aggressive scenario.
- Use outputs to set your next training or nutrition action for the week.
- Save or share this setup if you want to revisit it later, then check one easier and one harder version before you change your plan.
Questions people usually ask
What is Detraining Decay Estimator best used for?
Detraining Decay Estimator helps you estimate 1rm loss across a layoff using the mujika & padilla detraining model. so you can turn estimates into practical next steps.
How do I avoid misleading results?
Use realistic baseline inputs, run multiple scenarios, and update assumptions as your training, recovery, or nutrition changes.
Is this medical advice?
No. Outputs are general planning estimates and do not replace professional medical guidance.
Is this free and private?
Yes. Tools run client-side in your browser with no signup.
Formula
See the math
The underlying formula with variables defined, derivation shown, and a worked example with units.
Related Resources
Learn the decision before you act
Every link here is tied directly to Detraining Decay Estimator. Use the explanation, formula, examples, and benchmarks to pressure-test the calculator output from first principles.
How To Use
4 STEPSHow to Use Detraining Decay Estimator
Step-by-step guide for the Detraining Decay Estimator: inputs, interpretation, and reproducibility tips.
ReadFormula
4 VARIABLESDetraining Decay Formula
Detraining decay: strength −5-10% by week 4, −15-20% by week 8. VO2max −7%/week initially. Mujika 2010 meta-analysis.
ReadRelated deep dive
All articles →Read further
Long-form context behind the calculator output.
- Pillar·12 min
Detraining: How Fast You Lose Strength and VO2 Max
Mujika 2003 reviewed every detraining study to date. Strength holds for 4 weeks then drops 7 to 10 percent per week. VO2 max declines 7 percent per week.
Read - Article·7 min
Detraining Decay: 4 Weeks Off for a 3-Year Trained Lifter
Detraining math: 150 kg 1RM after 4 weeks off for a 3-year trained lifter loses 2.9% to 145.7 kg. Retraining 2 weeks to peak, the decay curve, and gaps.
Read
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