The foundation of clinical research in Duchenne Muscular Dystrophy (DMD) is often dependent on a limited number of primary and/or secondary efficacy functional assessments. These serve as the main endpoints for most current clinical trials with ambulatory subjects. Even when these functional tools have been validated, we have observed variability among patients at different time points. Due to their underlying psychological involvement, DMD patients are at risk for ADHD, OCD, and anxiety, which tend to limit a patient’s effort and engagement. This is without accounting for additional external factors – like lack of sleep, travel woes, and meal schedule – that regularly affect the performance of DMD subjects on these assessments. Therefore, we have designed a study to emulate the conditions of these tools, but applied to a population of healthy and cooperative adults, in order to observe any potential variations in performance over time. Our subjects (n = 10) will complete the six minute walk test (6MWT), North Star Ambulatory Assessment (NSAA), and four steps climb test (4SCT) at Baseline/Week 1 (already completed), Week 2, and Week 8. Our results will provide insight into the intra-subject variability within the healthy adult population. As members of the scientific and clinical community, we strive to increase awareness and efforts to identify, develop, and standardize new tools for accurate assessment of response to existing and novel therapeutic interventions in DMD.