Try swimming Hit the beach or the neighborhood pool for some swimming. It's a great workout that's low impact on your joints, provides great cardio, plus strength training. You will need goggles, a swim cap and a bathing suit and some flip flops
Hit the road for a great workout on a bike. Engage your legs, your balance, your upper and lower body and save gas. You will need a new or used bike, and a helmet.
Another great core workout is yoga. Don't let all the ohms and ah's fool you, things can get pretty intense combining strength and breathing exercises. Still not convinced? Try one class and see how you feel afterwards.
Remember that a good foundation for physical activity is a healthy diet. You'll want the most efficient fuel for peak performance. Learn about the right proteins, grains and healthy fats that will help sustain energy and enhance your performance.