Effects of Riboflavin in Mitigating Muscle Soreness in Ultra-marathon Athletes

The riboflavin 100 mg capsules will be self-dosed by the participant, one capsule prior to the long stage of the race followed by a second dose at the end of the long stage. Historically, long-stage finish times have ranged between 8 and 24 hours. The placebo will also be dosed as one capsule on the morning of the long stage, prior to the race start, and one capsule at the end of the long stage.