Lovemaking is just another form of exercise. As a rule of thumb, if you can walk 1.5 km or climb a few flights of stairs you should be fine. Try to gradually increase your lovemaking and be careful not to overdo it (this applies to all impotence treatments). Speak to your doctor if you are concerned about your fitness.

Most importantly, you should never take sildenafil if you are also using 'nitrates' (medications used for chest pain). If you are being treated for angina, ask your doctor if you are taking nitrates.