This is the broad framing Bennett printed on the title page of Old Age (1912): “All muscles and all organs increase in size, strength and elasticity when properly exercised. This is the principal secret of health, strength, elasticity of body, and a long life.” It is the longevity claim that places the case in this archive, and it is stated as a general mechanism rather than demonstrated: Bennett reasoned from the genuine observation that exercised muscle grows to the sweeping conclusion that exercising every muscle and organ secures a long life. It is classified as mechanism_only and unreplicated. No mortality or lifespan endpoint was ever measured for the regimen, and Bennett, who according to Stark (2018) did not believe any particular food could prolong life to extraordinary ages, offered no lifespan data for the exercises either. The step from “exercise strengthens muscle” to “exercise secures a long life” was asserted, not shown, and the evidence for the longevity claim is insufficient.