for the greatest overall health benefits experts suggest 30 minutes of moderate-intensity exercise on most (and preferably all) days of the week. doing aerobic activity for most of the days and strength (anaerobic) training two to three days of the week is recommended for best results. if you have been inactive for a while you may want to start with less strenuous activities such as walking or swimming at a comfortable pace. once you are in better shape you can gradually do more strenuous activity.
how much exercise should i do?