Running
Detraining Calculator
Estimate how training interruption may affect fitness over time.
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Fitness-loss estimates vary by training history, age, intensity and the length of the break.
Method and limitations
Fitness-loss estimates vary by training history, age, intensity and the length of the break. The exact method can differ between organisations, sports and populations, so use this page as a transparent starting point rather than a final decision.
For current standards, check the official governing body or competition notice. Keep a record of your inputs so you can compare changes over time under consistent conditions.
Frequently Asked Questions
Fitness-loss estimates vary by training history, age, intensity and the length of the break. The result is a planning estimate, not a diagnosis or guaranteed performance outcome.
Accuracy depends on measurement technique, the protocol used and how closely the input matches the reference population. Repeat measurements under similar conditions and use the result with relevant official guidance.
No. This tool provides general educational information. For medical decisions, injury concerns or official recruitment and competition eligibility, consult a qualified professional and the current issuing authority.
Disclaimer: This calculator is for general education and fitness planning only. It does not provide medical advice or guarantee eligibility. Read the full disclaimer.