The US Department of Health and Human Services has released new guidelines for physical activity.
Aerobic activities: Make your heart beat faster and can make your heart, lungs, and blood vessels stronger and more fit. Aim for 2 hours and 30 minutes of aerobic activity a week.
Strengthening: Make your muscles do more work than usual. Try this 2 times a week.
How many times a week should I be physically active? It is best to spread out your exercise over 3 or more days. How do I build up more physical activity? Do a little more each time. Then, you can trade activities at a moderate level for vigorous ones that take more effort. Remember, some physical activity is better than none, so even if you can't run a mile at first, building up to that mile is good exercise.
How can I tell if it's a moderate activity? If you are able to talk while doing it, but not sing.
How can I tell if it's a vigorous activity? If you can only say a few words without stopping to catch your breath.
Information courtesy of US Dept. of Health and Human Services