Author Affiliations: Departments of Medicine (Drs Beatty, Schiller, and Whooley) and Epidemiology and Biostatistics (Dr Whooley), University of California, San Francisco, and San Francisco Veterans Affairs Medical Center, San Francisco (Dr Whooley).
Narotzki et al correctly point out that the 6-minute walk test (6MWT) can be used as an outcome measure for exercise training interventions. In a sample of 24 healthy older adults, they found that 30 minutes of daily moderate-intensity walking for 12 weeks improved 6MWT distance by 59 m among men and by 53 m among women. A change in walking distance of more than 50 m is thought to be clinically significant in most disease states.1
Beatty AL, Schiller NB, Whooley MA. Moderate Exercise for Improvement in 6-Minute Walk Test Performance in Stable Coronary Heart Disease—Reply. JAMA Intern Med. 2013;173(2):168-169. doi:10.1001/jamainternmed.2013.1710