Cardio exercise is any sort of activity that stimulates the cardiovascular system by keeping the heart pumping at an accelerated pace for an extended period of time. Alongside a balanced diet and strength training, cardio exercise is essential to a lean, defined body and overall good health. In addition to melting fat, cardiovascular workouts bolster the bones, strengthen joints and improve cholesterol.

Include aerobic training options 2-4 times a week. Appropriate options include trail running, jogging, using an inclined treadmill, stair stepper, elliptical machine, walking up and down hills, or participating in step aerobic classes. While biking, rowing and swimming are aerobic options for the earliest stages of training, be sure as you get closer to your trip that you include activities that weight the back and legs the same way that hiking will. 

When starting your cardio program, begin with two weekly workouts of 30–45 minutes of sustained activity at a moderate intensity, and build to 3-4 aerobic sessions of sustained effort for at least 45–60 minutes. Be sure to include a 5–10 minute gentle warm-up before working at your target heart rate (for most workouts, choose a level of exertion that allows you to connect a few words together in a phrase, but leaves you feeling comfortably tired at the end of the workout), and cool down with 5–10 minutes of appropriate stretching.