COMPARISON OF OXYGEN-UPTAKE DURING A CONVENTIONAL TREADMILL TEST AND THE SHUTTLE WALKING TEST IN CHRONIC AIR-FLOW LIMITATION

The purpose of this study was to investigate the relationship between performance on the shuttle walking test and maximal oxygen uptake (Vo( 2)max) during a conventional treadmill test in patients with chronic a irflow limitation. Two different techniques were used to measure oxyge n consumption, ie. conventional Douglas bag techniques (treadmill test ) and a portable oxygen consumption meter (shuttle test). Initially, 1 9 patients performed a shuttle walking test (after one practice walk) and a maximal treadmill walking test, in a randomized, balanced design . Subsequently, 10 patients, (after one practice) completed an unencum bered shuttle walking test and one supporting the portable oxygen cons umption meter, in random order. The results of the first experiment re vealed a strong relationship between performance during the shuttle wa lking test and Vo(2)max during the treadmill walking test (r=0.88). Th e results of the second experiment consistently demonstrated an increm ental increase in oxygen consumption and ventilation in response to th e increasing intensity of the shuttle walking test. Again, a strong re lationship between go,max and performance an the shuttle test was demo nstrated (r=0.81). We concluded that the shuttle walking test is a val id field exercise test of functional capacity. Performance on the test relates strongly to Vo(2)max, the traditional indicator of cardioresp iratory capacity.