If you're hypertensive normally without medication, I'd be inclined to remain on the anti-hypertensives if you regularly exercise vigorously (and since your a cyclist I'm tipping you do) for their protective nature. If you sit systolic 150+ diastolic 90+ and start exercising, the subsequent increase in cardiac output can dramatically increase both of those numbers and you run risks of increased damage during those periods. If your resting BP has been dropping with a constant level of medication, by all means go talk to your doc about changing your meds, but going cold turkey on anything a doctor has prescribed you and you've agreed to is just dumb.

Also, explain to your doc that you do exercise vigorously and frequently. A beta blocker may not be the best approach given its mode of action.

Again, TALK with your doctor. Don't talk AT your doctor, and don't let them talk AT you. You're a major part of your own healthcare team.... the IMPORTANT part.