Why I use cycling as a way of Cross Training for the runners I coach:
Cycling is an excellent way to cross-train for competitive and casual long distance runners. Training with a bike can build endurance, muscle strength and leg movement, which all improves running times. It can provide a break from regular running workouts and lessen the chance of injury from running.
The fact that cycling works the front leg muscles which are not stressed in running helps balance leg muscles and reduces the chance of injury. It also helps stretch out leg muscles and gives the feet and ankles a break from the pounding of running. It is also excellent rehabilitation from injury or recovery from an intense or long run.
Bicycle training improves cardiovascular fitness because a cyclist is able to work for longer. Three or four miles of cycling is the equivalent of about a mile of running, so a cyclist keeps the heart rate and lung function at high levels longer. Longer workouts build endurance and can also help with weight control because longer periods of exercise burn more stored fat. I believe that’s the reason why some elite triathletes are able to run so well with only 3 run workouts a week. Whereas a 5-hour ride is normal for a serious cyclist, in contrast a 3.5 hour run is a very, very long run that needs a lot of recovery afterwards in comparison. Cycling wears you out less, which means you can go for hours and hours without causing too much muscle damage.
Complementing your run workout program with two one hour sessions a week will help you raise your performance. The sessions don’t need to be complicated, just holding 70% of your maximum for an hour 2 times a week will help. For better impact on your running keep varying your cadence throughout the workout.
I remember when I was in College in Florida two of my running team-mates went to Europe for the summer and toured Europe on bicycles. They were pedalling smoothly around four hours a day, but did no running at all. When they came back they were skinnier and stronger than ever and had the season of their lives. After observing that… what else can I say? It has worked ever since.