The aim of this study was to determine whether the 1-km treadmill walking test, previously developed to predict peak oxygen uptake (
O2peak) in stable cardiac outpatients, could be reproduced outdoors.
Fifty male cardiac outpatients performed the 1-km walking test on a treadmill and on a flat track within 1 week.
O2peak was estimated for both testing conditions considering age, height, weight, walking speed, and heart rate.
Average walking speed was slightly higher during outdoor conditions (5.73 ± 0.77 km/h vs 5.55 ± 0.84 km/h), whereas mean heart rates were similar for both testing conditions (102 ± 18 beats/min vs 103 ± 16 beats/min).
O2peak values for treadmill and outdoor tests were not significantly different (26.4 ± 4.1 mL/kg/min vs 26.8 ± 4.5 mL/kg/min) and were strongly correlated (r = 0.93, P < .0001). The slope and the intercept of the
O2peak values were not different from the line of identity.
This moderate and perceptually regulated 1-km walking test administered outdoors gives similar results compared with a similar test performed on a treadmill. Therefore,
O2peak can be reasonably estimated using both testing modalities. This suggests that the outdoor 1-km test can be applied for indirect estimations of cardiorespiratory fitness in an outpatient setting.
In 50 cardiac outpatients, outdoor and treadmill 1-km walking tests provided similar results. Data derived from the outdoor 1-km test can be used to provide a reasonable estimate of O2peak when evaluating cardiac outpatients.
Cardiac Rehabilitation and Prevention Program, Public Health Department, AUSL Ferrara, Italy (Drs Grazzi and Mazzoni); Center of Biomedical Studies Applied to Sport, University of Ferrara, Italy (Drs Grazzi, Conconi, and Mazzoni and Mr Lordi); Department of Public Health, AUSL Piacenza, Italy (Dr Chiaranda); Veterans Affairs Palo Alto Health Care System, and Stanford University School of Medicine, California (Dr Myers); and Division of Cardiology, “Delta” Hospital, AUSL Ferrara, Italy (Dr Pasanisi).
Correspondence: Giovanni Grazzi, MD, Università degli Studi Ferrara, Via Gramicia, 35, 44100 Ferrara, Italy (Giovanni.firstname.lastname@example.org).
All authors have read and approved the manuscript.
The authors declare no conflicts of interest.