Make Your Cardio Work for You

"The temperature changes, wind resistance and uneven terrain of the outdoors naturally increase your workload in ways indoor training doesn't," says Lewis. "Indoor training is important, though, because you can control the elements and, therefore, the parameters of your workout."

Lewis suggests you choose indoor cardio exercises that will complement your outdoor activity, such as a Spinning class or recumbent bike, if you plan to cycle, or a treadmill, if you like to walk around your neighborhood.

Whatever your chosen activity, you'll do two types of workouts: steady-state endurance and interval training.

"Endurance training allows you to do any activity for longer," says Lewis. "In contrast, interval training, which alternates moderate aerobic activity with intense activity, strengthens your heart and burns lots of calories, so you lose more fat. Put the two routines together and not only will your heart be in great shape, but so will your physique."