Near-Infrared Spectroscopy, Acute Taurine Supplementation, and Isolated Muscular Endurance and Fatigue Resistance in Young Healthy Adults

The goal of this clinical trial is to determine the association between near-infrared spectroscopy (NIRS)-derived mitochondrial oxidative phosphorylation (OXPHOS) capacity of the vastus lateralis muscles, and both local muscular endurance capacity and local muscular fatigability of the thigh muscles in young adults. Additionally, this trial aims to determine the effect of acute taurine supplementation on local muscular endurance capacity and local muscular fatigability when compared to a placebo condition. The main questions it aims to answer are: 1. Will there be a positive correlation between NIRS rate constant (a marker of mitochondrial function) and local muscular endurance capacity, along with a negative correlation between NIRS rate constant and local muscular fatigability? 2. Will acute taurine supplementation lead to improvements in local muscular endurance capacity and local muscular fatigability when compared to a placebo condition? Participants will: 1. Complete a NIRS assessment to non-invasively assess the mitochondrial capacity of both vastus lateralis muscles 2. Complete two acute supplementation assessment visits (separated by 7-10 days) which involve small blood collections before and after taurine or placebo supplementation 3. Perform a single-leg extension time-to-exhaustion test to measure local muscular endurance capacity on one leg, along with a repeated maximal voluntary isometric contraction fatigue index test to measure local muscular fatigability on the opposite leg, during each acute supplementation assessment visit.

Inclusion Criteria: * Capable and willing to give written informed consent * Capable of understanding inclusion and exclusion criteria * No medical condition that would limit participation in supervised exercise * No current prescription medications known to impact mitochondrial function * Sedentary or recreationally active (self-report average MVPA \< 300 mins/week) * Willing to allow researchers to use data for research purposes Exclusion Criteria: * Self-report history of diabetes mellitus * Self-report history of cardiovascular, peripheral vascular, cerebral vascular, pulmonary, or renal disease * Self-report history of uncontrolled hypertension (resting systolic blood pressure \> 180 mmHg or diastolic blood pressure \> 100 mmHg) * Self-report history of blood clotting disorders * Self-report history of sickle cell trait * Self-report history of myopathy leading to muscle loss, weakness, severe cramps, or myalgia * Self-report history of musculoskeletal disorders * Self-report history of lower limb musculoskeletal injuries that may cause significant differences in the functional capacities of the right and left legs * Self-report history of neurological disorders * Active tobacco, E-cigarette, or nicotine use * Recent (within previous 2 weeks) consumption of energy drinks or supplements containing ≥ 1 gram of taurine on \> 2 days/week * Actively taking medications to treat blood-clotting disorders * Any condition that, in the judgement of the Principal Investigator, may interfere with study participation and adherence to the protocol * Participants may be excluded if measured adipose tissue thickness is \> 2.0 cm at the site of NIRS assessment or if the accessor is unable to obtain high-quality NIRS signals