Cross-training is when exercisers alternate their fitness routine with something different yet complementary to their preferred, usual regimen. It aims to improve overall fitness by addressing whatever shortcomings their usual training has. A good example of this is a runner who occasionally cycles; running mainly uses the calf muscles while cycling mainly uses the quadriceps. By occasionally cycling, a runner can improve his ability to run up hills, since running up an incline relies more on the quadriceps.
It all makes intuitive sense, although science hasn’t necessarily validated all the various forms of cross-training for athletes. Nevertheless, cross-training is encouraged by coaches and fitness experts to elite athletes and non-elite athletes alike. A runner who occasionally cycles will be more fit than a runner who exclusively runs.
It is my opinion that both juggling and joggling are neglected as cross-training for a variety of athletic activities. Off the top of your head, think of all the various sports that require good hand-eye coordination, and upper body endurance, which juggling is very good at improving. While juggling isn’t the only way to improve hand-eye coordination, it is one of the most convenient and is also a moderate aerobic workout in its own right.
Consider boxers for example: They regularly run or use a jump-rope as cross-training to improve their overall aerobic fitness and endurance. However, neither of these helps optimize the critically important hand-eye coordination of the boxer, though jump-roping is slightly better than running in this regard. Jump-roping may be good for developing a good sense of rhythm and exercises the arms unlike running(even better if you can do a lot of tricks with the jump rope). It is still not as “good” as juggling.
Now imagine if instead of running or jump-roping a boxer joggled outside for a few miles or “joggled” in place at the gym with 3 balls. I believe this would be an improvement in their cross-training regimen, although I must admit I know very little about boxing. I believe it could improve their hand-eye coordination, unless they are doing something else as part of their training that has already optimized their hand-eye coordination.
If somehow the boxer could work his way up to juggling or joggling 5 balls, he may reap even more benefits. This is speculation on my part. Although I have never boxed, I did study martial arts for a few years which is similar. Juggling/joggling could also be used as cross-training for cycling, rock-climbing, tennis, martial arts, and so many other life-affirming activities. Even all by itself, it is fun and gives your brain a good workout.
For the record, I think joggling has improved my dancing ability, something which I had no ability to do before since I’ve always been a big klutz.