In reply
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