The human body has over 600 muscles. Each time you take up a new type of exercise, you feel muscles that have always been there, but you maybe never noticed - especially the second day when DOMS (delayed onset muscle soreness) sets in. I just enjoyed that experience of forgotten muscles.
On a trip to Chicago to visit my family, my daughter-in-law took my wife as a guest to her health club, where they got a great workout, and my wife used a Bosu Ball. If you don't know what one is (I didn't because I don't go to health clubs), imagine the upper third of a large ball cut off, sitting on top of a sturdy plastic base. She returned tired and enthused and, knowing I'm always looking for ways to keep exercise interesting and challenging, suggest we get one. We made it our Xmas present to each other.
Although the Bosu Ball is marketed as a device to improve balance, it's much more than that. If you go to any good website, like the Bosu inventor's BosuFitness, you'll find an array total body exercises. I find it fun and plenty hard. It's one of those devices that if you slam it hard, it slams you hard back because the top is an inflated, heavy rubber bladder that easily holds your body weight and rebounds when you compress it, a little like a trampoline.
My legs, especially my ankles and calves, are pretty strong from trail running, where you have to constantly adjust to rocks and ruts. But after twenty-five minutes on the Bosu Ball while following three expert instructors on a DVD, my legs burned and my balance started to break down. I noticed that instead of relying on my legs to lift me on and off the ball, I was wildly swinging my shoulders and my ankles became wobbly.
I thought about an article at SportsGeezer.com that highlighted research conducted at the University of Indiana about the relationship of running injuries to fatigue. The article discusses how as fatigue increases, it causes small changes in running form. A small group muscles starts to fail first, then other muscles compensate to keep the runner going forward. As you tire more, you lose muscle control, causing instability and poor form. Your body loses its natural balance, placing additional stress somewhere else, which eventually causes an overuse injury becaused physical forces are transferred to muscles not normally enlisted in the activity.
All the muscles in the body are connected, head to toe, through what kinesologists and exercise physiologists call the kinetic chain. Most rigorous activities engage almost every muscle to one degree or another. However, training in a particular activity increases the strength and endurance mainly in the muscles enlisted for the particular activity. When the primary muscles used in an activity start to fail, the secondary ones come to the rescue.
So when you start exercising in a new activity or with a new apparatus, new muscles are being engaged. I'm in good shape for what I do a lot, and not for things I don't. Because you are a strong runner will not translate that you will also be a strong bicycle racer. Psychologicallly, cross-training has great benefits to keep from getting bored, but the actual performance benefits are limited.
What the Bosu Ball reminded me is that you have to remember you're a beginner and slowly build your muscles and reflexes for the new activity. I was having a great time and going hard, but it was new to some of my muscles, and they tired faster than usual and lost coordination. Ironically, if you are exercising hard, you can actually be slightly hypoxic, which means your brain becomes short of oxygen and you don't think straight or recognize you've entered the potential injury zone.
One advantage of being a TOJ is you're (usually) smart enough to stop because injuries happen when you start to tire. You've been in various states of fatigue many times before, and understand physical success takes time and persistence. Skills only come with repetition.
I jumped back on the Bosu today and felt those forgotten muscles again. But they already were learning what to do. And I was on it for several more minutes then the first time before my kinetic chain started to breakdown. Ah, progress.