C-25C Free Communication/Slide Diabetes and Exercise
Exercise training has been recommended in individuals with Type II diabetes for its beneficial effects on glycemic control and cardiovascular disease risk reduction. Percent heart rate reserve (%HRR) and the rating of perceived exertion (RPE) are two widely used methods of assessing physical effort during exercise. Although these measures are considered valid and reliable in healthy adults and some special populations, they have not been validated in adults with Type II diabetes mellitus.
To examine the relationships between exercise intensity as measured by percent VO2 peak (%VO2) and both RPE and %HRR in adults with Type II diabetes mellitus. It was hypothesized that RPE and %HRR would be equally highly correlated with %VO2.
Thirteen adults (49.6 ± 12.15 yrs) with duration of diabetes (range 0.5–32.0; mean 9.0 ± 9.66 yrs), completed a maximal graded exercise treadmill test with 2-minute stages to VO2 peak (2.16 ± 0.782 L/min). Rate of perceived exertion using the Borg 6–20 scale was assessed during the last 30s of each stage. Heart rate was monitored continuously via 12-lead ECG and heart rate reserve was calculated. Correlation coefficients were determined between %VO2 and %HRR and between %VO2 and RPE. A test of significant differences was performed between the two correlation coefficients.
Correlation coefficients of 0.909 and 0.602 were found between %VO2 and %HRR and between %VO2 and RPE, respectively. A t-test of the difference between the correlation coefficients revealed a significantly stronger relationship between %VO2 and %HRR than between %VO2 and RPE, (p < 0.05).
Percent heart rate reserve has a stronger association with exercise intensity than rating of perceived exertion in the Type II diabetic population. Funded by the Indiana University Adult Fitness Program.