Nicotinamide Mononucleotide Supplementation for Exercise Tolerance Improvement in Healthy Older Adults

This is a randomized, double-blind, placebo-controlled, two-arm crossover clinical trial evaluating the effects of nicotinamide mononucleotide (NMN) combined with trimethylglycine (TMG) supplementation, compared to NMN alone. The study will assess safety and efficacy in improving exercise tolerance and modulating biomarkers of aging in healthy older adults. The primary outcome is cycle ergometry constant work rate (CWR) exercise tolerance, measured as time to fatigue. Secondary outcomes include changes in peak oxygen consumption (VO₂peak), critical power, anaerobic work capacity, lactate threshold, and NAD⁺ metabolite levels. The supplements have been used in prior exploratory studies and real-world applications, which have helped inform the design of this current trial.