Beta Blockers and Exercise: What You Need to Know
If you’ve been prescribed a beta blocker, you’re not alone. These medications are commonly used in people with heart disease. Doctors prescribe them to lower the workload of the heart, reduce symptoms such as chest pain, prevent dangerous heart rhythms (arrhythmias), and even improve long-term survival after a heart attack. In simple terms, beta blockers calm the heart down so it doesn’t have to work as hard.
One of the main ways they do this is by lowering your heart rate. That means your heart won’t beat as fast, especially when you’re exercising. While this is usually good for your heart’s health and safety, it can also affect your fitness and how you measure your exercise intensity. Let’s take a closer look.
How Beta Blockers Work
Beta blockers work by blocking the effects of stress hormones—mainly adrenaline—on your heart. Normally, adrenaline makes the heart beat faster and with more force. Beta blockers attach to specific receptors in the heart (called beta-adrenergic receptors) and dampen this response. The result is a slower heart rate, lower blood pressure, and ultimately less strain on the heart muscle.
Why Beta Blockers Are Prescribed
For most heart patients, beta blockers are prescribed to:
Lower the heart’s oxygen demand – easing chest pain (angina) and protecting the heart muscle.
After a heart attack – to prevent future attacks and improve long-term survival.
Control abnormal heart rhythms (arrhythmias).
Treat heart failure (chronic, stable) – certain beta blockers help the heart pump more effectively.
Manage high blood pressure (hypertension) – especially when other medications are not enough.
Support conditions like hypertrophic cardiomyopathy or aortic dissection – by slowing the heart rate and reducing strain on the arteries.
Beta blockers aren’t only for the heart. Doctors may also prescribe them for:
Migraine prevention
Essential tremor (shaky hands)
Anxiety, especially performance anxiety (like public speaking or stage fright)
Overactive thyroid (hyperthyroidism) to slow a racing heart
Glaucoma (as eye drops) to lower eye pressure
No matter why they’re prescribed, one of the most noticeable effects of beta blockers is a lower heart rate. And for people who exercise—especially heart patients—this can change how workouts feel and how progress is measured.
How Beta Blockers Affect Exercise Capacity
The Fick equation (below) summarized the 3 components that determine cardiovascular fitness.
VO₂ = Heart Rate × Stroke Volume × A-V O₂ Difference
That sounds complicated, but here’s the simple version: your ability to use oxygen during exercise (your VO₂, or aerobic capacity) depends on how fast your heart beats (Heart Rate), how much blood it pumps per beat (Stroke Volume), and how well your muscles absorb and use the oxygen in that blood known as the arterial venous oxygen difference (A-V O₂ Difference).
Your peak heat rate (how fast your heart is capable of beating at an all out cardiovascular effort) is mostly limited by age and can be roughly estimated by taking 220-age. There is some evidence that trained athletes can achieve peak heart rates above the 220-age estimate, however, fitness gains derived from exercise training are mostly the result of an improved stroke volume (stronger heart beat) and a widened A-V O₂ Difference (representing an enhanced ability of the muscles to extract oxygen from the blood).
Since beta blockers lower your maximum heart rate, they can reduce your peak exercise capacity. For example, if your heart used to reach 160 beats per minute during a brisk walk or bike ride, on a beta blocker it might only reach 120–130. That doesn’t mean you’re weaker or doing something wrong however at high levels of exertion the blunting of your heart rate may lead to premature fatigue and exercise intolerance as the higher heart rates are no longer available to you.
The important thing to remember is that while your “top speed” may be lower, exercise is still safe and highly beneficial. In fact, exercise and beta blockers often work hand-in-hand to protect your heart.
Timing Matters
Another factor to consider is when you take your medication. Some beta blockers are taken once a day, others twice a day. If you take your dose in the morning, the effect is usually strongest in the first several hours. Later in the day, the medication may start to wear off a little, which can change how your heart responds to exercise.
That’s why your exercise heart rate at 8 a.m. might look different than at 5 p.m, even if you’re doing the same activity. This doesn’t mean the medication isn’t working or that you are necessarily under or overexerting yourself; it’s just part of how the drug is absorbed and cleared from your system. It is important, however, to understand that if you need to limit your heart rate below a certain threshold, for example due to anginal symptoms or defibrillator trigger rates, that exercising in the evening may yield higher heart rates.
Heart Rate, Smartwatches, and RPE
If you monitor your workouts with a smartwatch or fitness tracker, you’ve probably seen that they come pre-set with heart rate “zones” based on age. But here’s the catch: those zones assume you’re not on a beta blocker. Since your heart rate is lowered by the medication, the watch’s ranges may not apply to you and may provide incorrect feedback that you are not working as hard as you should.
That doesn’t mean you should ignore your heart rate completely. It’s still useful, especially for tracking trends. But a better tool for many patients on beta blockers is RPE (Rating of Perceived Exertion). This is a simple 0–10 scale where you rate how hard the exercise feels. For most heart patients, working in the 3–5 range (moderate to somewhat hard) is safe and effective. Match the heart rate you observe on the watch to an RPE of 3-5 and that is a good reference for your training heart rate zone. You can also use your breathing as a guide. Your exercise heart rate should align with the intensity that provokes a mild to moderate increase in your breathing.
What If Your Beta Blocker Is Stopped?
Sometimes, your doctor may decide to reduce or stop your beta blocker. If that happens, your heart rate will often rise back to what it was before the medication.
A simple way to adjust is by comparing your new heart rates to what you were used to. For example
On a beta blocker: walking at 3 mph gave you a heart rate of 110 bpm.
Off the beta blocker: the same walk now gives you 130 bpm.
Nothing has changed about your fitness—the only difference is the medication. That 130 is now your “new normal.”
Side Effects and Exercise Considerations
While beta blockers are generally safe, they can sometimes cause side effects, especially when you’re active:
Fatigue or lower energy levels
Dizziness or lightheadedness
Cold hands or feet
In some cases, changes in blood sugar response (important for people with diabetes)
If you notice severe dizziness, fainting, or unusual shortness of breath, it’s important to check in with your healthcare team.
The Takeaway
Beta blockers are powerful, protective medications for people with heart disease. They do lower your heart rate, which can reduce your exercise tolerance at high levels, however that doesn’t make exercise less important. In fact, staying active is one of the best ways to strengthen your heart and improve your quality of life.
Here are a few key reminders:
Expect a lower maximum heart rate while on beta blockers.
Use RPE (how hard it feels) to set your heart rate zone.
Be aware that medication timing can affect your workout heart rate.
If your beta blocker is stopped, your heart rate will likely rise—this is normal.
Always check with your healthcare team before making changes to your exercise or medication plan.
Your heart is still benefiting from the work you put in. Think of beta blockers as helping your heart stay calm and steady while you get stronger.
Final Thoughts
If you’re on a beta blocker, don’t think of it as something that limits you—think of it as something that helps protect your heart while you build strength and fitness. Exercise is still one of the best medicines you can give yourself. Stay consistent, focus on how you feel rather than chasing heart rate numbers, and remember that every step, pedal stroke, or lap you take is making your heart healthier.
If you have questions about exercising while on medications or any questions about exercise and health please do not hesitate to reach out to us. Our Exercise Physiologists are here to help you achieve your health and fitness goals.
The information in the blog is provided for informational and educational purposes only and does not constitute medical advice. The information is not a substitute for professional medical advice, diagnosis, or treatment. For questions please follow up with your healthcare professional.
