Cross training is an exercise regimen that utilizes several modes of cardiovascular training within a single session. By combining different modes of exercise (e.g. running, biking, stepping, elliptical striding, etc.), you prevent the same bones, muscle groups and joints from being stressed over and over. As a consequence, cross training reduces the likelihood of your being injured as a result of over-training. In addition, cross training has also been shown to have a positive effect on cardiovascular function and a person's long-term adherence to a training program.