The minimum amount of an intervention needed before a measurable effect appears.
The point on a dose-response curve below which an exercise, training load, or rehabilitation intervention produces little or no detectable benefit (or harm), and above which effects begin to scale with dose. Thresholds are typically estimated from population-level data and vary by outcome, tissue, and individual, so a value derived for one context (e.g., tendon adaptation) shouldn't be assumed to transfer to another (e.g., cardiovascular fitness). Precise threshold values are often contested or study-specific, and many relationships are better described as graded than as a sharp cutoff.
This guide was auto-drafted and is pending editorial review.