By Peter Pfitzinger | DistanceCoach.com
As I rode the exercise bike in the lab this morning, it occurred to me that there are 3 good reasons to cross train: 1) you are injured and can’t run, so you need to do something to keep your sanity; 2) you want to improve your cardiovascular fitness without getting injured; or 3) you want to improve your running by doing other activities (such as weight lifting or yoga) that do not target your cardiovascular system.
The first 2 reasons to cross train involve maintaining or improving your cardiovascular fitness. Cycling, rowing, in-line skating, swimming, stair climbing, and deep water running fall in this category. The third reason covers all of the other activities you can do to enhance your running performance. Weight lifting, yoga, and stability ball sessions fall into this category. In this month’s column we will focus on cross-training to improve aerobic fitness, and next month we will look at other forms of cross training.
Studies have shown that predictable training errors such as increasing mileage or adding speedwork too quickly lead to the majority of running injuries. Just as the risk of coronary artery disease can be reduced through regular exercise, so can the risk of running injuries be reduced through modifying risk factors. One way to do this is to reduce pounding on the legs and back by substituting other forms of exercise for a portion of your running.
But, won’t your racing performances suffer if you replace some of your running with cross training? The Principle of Specificity of Training says that your body adapts very specifically to the type of training that you do. That is why you wouldn’t have much success as a runner by doing all your training on the bike or in the pool. But, what if the majority of your training is running, can you enhance your cardiovascular fitness by doing other types of aerobic workouts? Let’s see what the research says.
In a 1995 study published in the European Journal of Applied Physiology, Carl Foster, Ph.D. and colleagues investigated the effects of increasing training volume via additional running versus as equal increment of cross training. Thirty reasonably well-trained runners were divided into 2 groups. One group (run + run) increased their running mileage by 10% while the other group (run + swim) added an equivalent amount of swimming to their training. After 8 weeks of increased training, the run + swim group improved their 2 mile race performance by 13 seconds whereas the run + run group improved their 2 mile time by 26 seconds. In addition, the 4 mmol lactate threshold improved in the run + run group but not in the run + swim group. The results of this study suggest that even reasonably well-trained runners can improve their running performance through cross-training, but that the improvement is likely to be less than through increased running.