Beta blockers and exercise fatigue: what to know

Beta blockers reduce the effects of adrenaline on the heart. Your resting pulse may be lower and your heart may not speed up as much during exercise, so the same walk, stairs, or workout can feel more tiring. This effect varies with the medicine, dose, fitness, and the condition being treated. Fatigue may also come from dehydration, anaemia, recent COVID-19, burnout, chronic fatigue syndrome, coeliac disease, kidney disease, alcohol use, poor sleep, or another medical problem. The medicine may be contributing without being the only explanation.

Take the medicine exactly as prescribed and never stop it suddenly, because abrupt withdrawal can be unsafe for some conditions. Begin activity gently, extend warm-up and cool-down time, and judge effort by symptoms and how you recover rather than a target pulse alone. Keep a record of the dose time, activity, fatigue, dizziness, breathlessness, and recovery. Arrange a medication review if fatigue started after treatment began, followed a dose change, or limits ordinary activities. A clinician may adjust timing or treatment after checking your heart rate and blood pressure.

Stop exercising and seek urgent help for chest pain, fainting, severe breathlessness, new confusion, or a fast or irregular heartbeat with feeling unwell. Contact your clinician promptly for worsening swelling, persistent dizziness, marked weakness, or fatigue that is accompanied by fever, weight change, bleeding, or reduced urine. These features may point to a problem beyond the expected exercise effect.

Is my fatigue an expected effect of this beta blocker? What intensity of exercise is suitable for me? Should I monitor pulse or blood pressure? Could another condition or medicine be contributing?