How Helpful are Cross-Training Work-Outs? Excerpts... "Note also that the cross-training arguments are definitely biased toward the idea that cross training is a good thing. We have three key positives about cross workouts: higher workout intensities, improved leanness, and greater strength with only one real knock against them: the lack of specificity. That's probably why scientific research has been very kind to the concept of cross training. There are now four separate studies documenting improvements in running capacity after runners took up biking. In two of those studies, runners completely substituted cycling for running; in two others, they added cycling to their existing running programmes. Other studies have suggested that stair stepping and aqua-running can do a nice job of preserving running capability when it's not possible to run. And we still haven't mentioned the possible mental benefits of cross training. If you can learn to mentally tolerate a super-tough bike workout, you can probably better cope with the pain of running fast, too. Plus, it's important to consider the 'muscle-trauma scenario'. Let's face it, most runners do a great job of battering their legs. They run when they're tired, run when they're hurt, run so much that they never really let their leg muscles recover completely. Switching over to bike workouts can at least produce partial recoveries, because it prevents the damage which can accrue to leg muscle cells when a tired runner decides that a 20-miler is just the thing to improve fitness."