 Participants will take part in a prospective, single center, randomized, double-blind, clinical study of 2.0 gday of SRT2104 or placebo test material administered orally as 0.25 g capsules. The study will evaluate the effect of 28 days of consecutive SRT2104 dosing upon muscle strength, metabolism and structure of the ankle muscle group following a 14 day leg immobilization period. The study will also evaluate pharmacokinetic parameters as well as the safety and tolerability of 2.0 gday of SRT2104. Thirty-four 34 healthy male and female subjects aged 18-40, who fulfill the inclusionexclusion criteria, will be enrolled in this study. Subjects will be randomized 1:1 to receive either 2.0 gday of SRT2104 or placebo in a fed state for 28 consecutive days. Subjects will remain on a fixed dose of test material for all dosing days in the study. 