Why should you cross train and why is it good for you? Running is, arguably, the fastest way to get fit. Running helps build lung capacity, a stronger heart, aids in weight loss, and who doesn't want great legs?!? But with all of those benefits, you should still add some other training to your weekly schedule. The biggest benefit of cross training is it can aid in injury prevention by helping correct muscle imbalances. If you are only running, you will probably start noticing overuse injuries. Incorporating some form of cross training into your weekly workout will help build strength and flexibility in muscles that running typically doesn't utilize.
One cross training option is a cardio workout that is similar in style and benefits to running. These are lower impact options like the elliptical trainer, swimming, or water running. Participating in these low impact cardio activities can help reduce the stress to the joints that running applies while still allowing you to get a workout in and maintain your fitness level. Switching up the workout every now and then will also help to prevent burnout.
Below are some good cross training options:
Elliptical - You get a total body workout. The motion provides you with a cross country skiing/walking feeling. It also enables you to move forward and backward to utilize the major leg muscles.
Cycling/Spinning - Whether you're on the road or in a spin class, cycling is one way to get a cardio workout and strengthen your quads. Running works the hamstrings while cycling will help build the hamstring's opposing muscle group: the quadriceps.
Swimming - This exercise allows you to build endurance, flexibility, and strength while giving your joints a much needed rest. You can swim laps or find a water running program to help you get your training in while recovering from an injury.
Yoga - provides a great full body workout that strengthens your muscles while not making them bulky. Yoga also increases flexibility and helps prevent injuries by keeping your muscles loose.
Resistance/Weight Training - Whether you use your own body weight (pushups) or free weights, strength training helps improve form, builds core muscles, and helps balance muscles. Muscle imbalance is a major source of injuries in runners.