Six-minute walk test: a tool for predicting maximal aerobic power (VO2max) in healthy adults

BackgroundThe 6-min walk test (6MWT) is cost-effective and well-documented field test for assessing functional exercise capacity and response to medical interventions in diverse patient groups, and predicting cardiorespiratory fitness among healthy people. ObjectiveAssessments of cardiorespiratory fitness in terms of maximal aerobic power (VO(2)max) have great potential in public health monitoring to predict future health, early retirement and ability to independent living. This study aimed to develop a prediction model for VO(2)max based on 6MWT results among healthy adults. DesignThe study comprised of pilot and validation studies. In validation study, seventy-five 19- to 75-year-old adults (39 men, 36 women) were equipped with portable gas analyser and heart rate monitor. Participants performed 6MWT on a 15-m indoor track and maximal graded exercise test (GXT) on a treadmill. We evaluated performance of the developed prediction model among 1583 Finnish adults. ResultsParticipant's mean walking distance was 652m (SD74). Their mean VO(2)max in GXT and O-2 uptake at the end of the 6MWT were 344mlkg(-1)min(-1) (SD +/- 76) and 272 mlkg(-1)min(-1) (SD +/- 65), respectively. For men, the best predictors for VO(2)max were walking distance, age, BMI, heart rate at the end of 6MWT and height, and for women, walking distance, age and weight. The predictors explained 82% and 79% of men's and women's measured VO(2)max with the standard error of estimate of 36mlkg(-1)min(-1) and 35mlkg(-1)min(-1), respectively. ConclusionThe 6MWT performed along a 15-m track is a valid field test for predicting VO(2)max of healthy adults with accuracy of about 1MET.