According to recent studies get at least 150 minutes of moderate aerobic activity or 75 minutes of vigorous aerobic activity a week, or a combination of moderate and vigorous activity. The guidelines suggest that you spread out this exercise during the course of a week. Also partake in strength training exercises for all major muscle groups at least two times a week. Aim to do a single set of each exercise, using a weight or resistance level heavy enough to tire your muscles after about 12 to 15 repetitions. Moderate aerobic exercise includes activities such as brisk walking, swimming and mowing the lawn. Vigorous aerobic exercise includes activities such as running and aerobic dancing. Strength training can include use of weight machines, your own body weight, resistance tubing, resistance paddles in the water, or activities such as rock climbing. As a general goal, aim for at least 30 minutes of physical activity every day. If you want to lose weight or meet specific fitness goals, you may need to exercise more. Want to aim even higher? You can achieve more health benefits, including increased weight loss, if you ramp up your exercise to 300 minutes a week.