Lopressor and exercise

[Dugald]

My cardiologist has put me on Lopressor twice a day to reduce my heart rate and blood pressure and tells me to do aerobic exercise everyday for 45 minutes. Given the polar opposite effects of these two requirements, and given the fact that the effects of Lopressor wear down during each 12 hour period, when is the optimum time to exercise to maximize the benefits and at the same time respect the intent of the Lopressor?

[kenkeith]

Significant beta-blocking effect (as measured by reduction of exercise heart rate) occurs within 1 hour after oral administration, and its duration is dose-related. For example, a 50% reduction of the maximum registered effect after single oral doses of 20, 50, and 100 mg occurred at 3.3, 5.0, and 6.4 hours, respectively, in normal subjects. After repeated oral dosages of 100 mg twice daily, a significant reduction in exercise systolic blood pressure was evident at 12 hours.