And by John Atkins
Mountain biking is a full-body workout, and, better yet, it has little impact on the joints. It targets the quadriceps, hamstrings, gluteals, calves, lower and upper back and shoulders. (It's also a good leg burner on tough trails.) Pump hard for a good cardiovascular workout, and stay balanced on the downhills to help you get comfortable moving at speed.
Place the top of your left foot on a chair and slowly squat 3-4 inches on your right leg. (To avoid stressing your knee joint, make sure your right knee does not get ahead of your toes.) Now return to the slightly bent-knee start position. Do three sets of 10 repetitions on each leg. Work up to three sets of 20 repetitions.