Moderate evidence

The popular acute-to-chronic workload ratio has serious conceptual and statistical problems, and shouldn't be treated as a rule for safe progression.

In practice

Be sceptical of anything claiming a precise safe percentage to increase by. Sensible progression means small increases, watching how you respond, and backing off when something complains — not a number that guarantees safety.

Source

• Impellizzeri FM, Tenan MS, Kempton T, Novak A, Coutts AJ (2020). Acute:chronic workload ratio: conceptual issues and fundamental pitfalls. International Journal of Sports Physiology and Performance, 15(6):907–913. doi.org/10.1123/ijspp.2019-0864