More hints on practicing, by Mark Olson.
After about a total of 100 or so throws in a left-shower (3-ball, with drops) the muscle in my left hand starts protesting. [the muscle above the elbow, don't know its name] ... should I continue and beat it into shape so its ready for 5-cascade, when i get there, or should I gracefully retreat (temporarily) so that I can live to juggle another day?
Over-exerting tired muscles and tendons can lead to muscle pulls, over time it can contribute to Repetitive Strain Disorders such as Carpal Tunnel Syndrome and Tendonitis, and, believe me, you don't want to suffer from these. The best thing to do is prevent the cause any factors that may contribute to pain. 1) Warm up. If you don't know how to warm up, contact a local coach, physical therapist, or sports doctor. There are also a number of good books on stretching, which is what you want to do, ever so gently. There are great benefits to warming up, warm muscles will perform better than cold muscles, you will get more out of your workout. 2) Relax. Relaxed muscles react better than tense muscles. Relaxed muscles, IMHO, will not tire as easily. To this end you can do quite a bit that will benefit not only your juggling but your life as well. Meditate, take up Yoga, Take up Feldenkrais. I recently restarted Alexander technique after a 15 year hiatus. It really helps keep my body relaxed at all times. Stop and shake your arms after a drop. Also, do what you can to reduce stress in your life. Stress will carry over into your practice session and cause you muscles to tense up. If you can't change the things that cause stress in your life, change the way you react to those things. 3) Breath, and deeply. Oxygen is wonderful stuff, your muscles and tendons will agree. Fill you lungs with oxygen when you shake those arms between drops. 4) Get into shape, and keep in shape. Fit muscles warm up faster and respond better. They are also less prone to injury. I highly recommend aerobic exercise. Exercise physiologists and sports medicine professionals are now discovering that moderate exercise such as walking at a brisk pace can be just as beneficial as intense aerobic exercise. Unicycling is an excellent complement to juggling and provides excellent exercise as well. 5) Cool down. After juggling, walk around, shake those muscles, stretch them gently, let your heart rate come back down to earth. This will prevent cramping. 6) Warm up to those hard tricks. This last winter I really pushed working on 5 balls. I was so anxious to be able to juggle five, that I would jump right in, and without warming up, work on five balls. The result was that my CTS flared up like there was no tomorrow. Work on the easier tricks first and keep relaxed. I can get good runs of five together now and stay relaxed. Also, if you juggle clubs, I recommend warming up with other props first. The motions involved in club juggling and the impact from clubs landing in your hands are particularly conducive to injury. 7) If it hurts, don't do it. And, most importantly, find out what's causing the pain. This is a tough one because often times the thing you want to do causes the pain. One thing I noticed, when I was really pushing 5, was that I was really hurting myself be experimenting with my hand position. I was turning my palms so that they were face up, parallel to the floor. It turned out that I turned them too far. This was exacerbating my injury. You can videotape your workout and review it to see if you can find out what's causing the pain. If you can't figure it out, take your video to a physical therapist or a doctor and see if she or he can figure out what's causing the pain. If your pain persists, and you haven't done so already, see a doctor. Muscle injuries and Repetitive Strain Disorders are just like any other health problem, if you catch it early and do something about it, your chances of recovery are excellent. Even a persistent small pain. An ounce of prevention is worth it. Make sure, too, that you go to your doctor armed to the teeth with descriptions of your symptoms. "It hurts from here to here, it's a tingling pain that will persist for thirty minutes." General symptoms will elicit a general diagnosis. You truly want to find out what the cause of they pain is and do what you can to keep the pain from coming back. I'm sorry that I've been so long-winded but I believe very passionately in these things. If you warm up, learn to relax, breath deeply, get into shape. and cool down, your juggling will improve and the way your body responds will improve. You will also reap benefits ten, twenty, thirty years from now.