Objective: Co-morbidities are found to affect metabolic equivalents (METs). Therefore the main objective of this study was to compare METs (1 MET: oxygen uptake (VO2) 3.5 mL·kg-1·min-1) during an incremental shuttle-walking test (SWT) between non-cardiac and post-myocardial infarction (MI) men, and secondly to determine any differences in VO2 (mL·kg-1·min-1) between flat treadmill walking and the turning during the shuttle-walking in non-cardiac subjects.
Design: Comparative study.
Subjects/patients: 31 post-MI (mean ± SD, 63.5 ± 6.5, range 53-77 yrs) from phase III cardiac rehabilitation and 19 non-cardiac (64.6 ± 7.5, range 51-76 yrs) men participated.
Methods: All subjects performed a SWT, and non-cardiac subjects a treadmill test (TM) of similar protocol. Throughout both, subject’s VO2 was measured.
Results: Analysis comparing lines of regression showed: METs at 1.12 to 4.16 m·h-1 were higher (P<0.0001) for post-MIs vs non-cardiacs. For non-cardiacs, there were no differences between the TM and SWT (P>0.9) and LoA showed acceptable agreement in METs between TM vs SWT, mean difference -1.1±8.8 (1.96SD).
Conclusion: It would appear that for asymptomatic individuals it is appropriate to apply established METs for flat walking to the SWT. However, the significantly higher METs for the post-MIs compared to the non-cardiac subjects indicates the need for caution when using METs derived from healthy subjects in the prescription of exercise for MI patients.
- Special populations
- exercise prescription