At least 20 minutes 3 times per week
Any sort of exercise you enjoy will do, as long as it makes you out of breath and you can do it at least three times per week. Examples include bicycling, jumping rope, treadmill, aerobics classes, running, or swimming. “Start and stop” exercises, such as most sports or weight-lifting, may be a lot of work, but they don’t help your health with same way.
Most people cannot do aerobic exercise for 20 minutes the first time they try. See how long you can go the first time, then as you get in better condition you should be able to add two minutes each week. Do not push yourself so hard that you become dizzy.
This sort of exercise has many benefits, including losing weight, lowering your blood pressure, lowering your “bad” cholesterol (LDL), raising your “good” cholesterol (HDL) and toning up your muscles.
Even if you do not lose weight, you still get the other benefits. If you do lose weight, the exercise gets easier and easier. Many people find that the exercise helps them lose more weight than diet alone, and losing weight allows them to exercise more, leading to more weight loss, and so on.