Use of the six-minute walk test in exercise prescription in male patients after coronary artery bypass surgery

INTRODUCTION: It is unclear whether it is possible to determine the training load on the basis of the 6-minute walk test (6-MWT) in patients after cardiac surgery with low tolerance of physical exercise. AIM: Use of the 6-MWT to determine an individual initial training load in walking training on a treadmill in the early phase of cardiac rehabilitation in men after coronary artery bypass graft (CABG) surgery. MATERIAL AND METHODS: Twenty-two men aged 54 to 74 years, up to 3 months after CABG surgery participated in walking training on a treadmill (12–15 sessions). Patients underwent the initial and final treadmill exercise stress test (TEST) and the 6-MWT. Based on 6-MWT results, the initial training load was prescribed. Before the 6-MWT and 3 minutes after its completion, lactate concentration was determined. RESULTS: The 6-MWT distance increased from 420 ±80 m to 519 ±61 m (p < 0.001), and the energy expenditure from 4.4 ±1.4 MET to 6.3 ±1.3 MET (p < 0.001). There was a positive correlation between 6-MWT distance and energy expenditure in the TEST before rehabilitation (r = 0.60, p = 0.005), and after rehabilitation (r = 0.75, p < 0.001). A negative correlation was found between the baseline 6-MWT distance and distance increment in the final 6-MWT (r = –0.66, p = 0.002). The 6-MWT did not induce hyperlactatemia. CONCLUSIONS: The 6-MWT can be used in exercise intensity prescription, especially for determining the individual initial training load, load progression, as well as its correction during follow-up tests.