At the beginning of an academic year, before attrition does its work, the Wash U Traditional Karate Club tends to have a lot of new members. A few of these will have done a martial art of some kind before, but most will not have, and the bulk of new trainees, being undergraduates at Wash U, will be young (18-22) and intelligent, but they aren’t usually the kind of people that come across as tough, or hard-bitten; for the most part they give the impression that the real fights and struggles in their lives so far have been emotional and social, rather than physical, and if they do have a bit of muscle on them, or some chronic injuries, chances are good that they got both playing sport, and not working down a mine. (Would that all 18 year-olds were so fortunate, of course.)

In a way, this is a gift: you have a group of students who are physically mature, intellectually capable of learning, of understanding your explanations, warnings and suggestions, who have no interest in hurting themselves or each other physically, and whose youth means that there is vast potential for quick muscle growth, and accompanying improvements in stability, agility and nervous control.

This year is especially interesting for us in that a majority of our new recruits are women. (We always wondered whether having me as an instructor would attract more women to the club, but this is the first time there have been more than two women in the dojo at once in ages.) Untrained women often have less upper body strength than we would like. I certainly didn’t have enough when I started: I remember some guy telling me to tense my latissimus dorsi to drop and stabilise my shoulder, putting my hand on my ribs at the side to try to feel the muscle he was talking about and saying to him (only half joking) “I don’t think I actually have that muscle.” I could find skin, subcutaneous fat and rib-bones, but that was about it.


Four years of conditioning later, and three classes ago, we got the medicine ball out for the first time this semester, and used throwing it back and forth as a warm-up while we were waiting for the stragglers to arrive. Playing catch with the medicine ball involved the usual mugging and teasing as people discovered for themselves that it’s a bit heavier than it looks, dropped it, threw it short, and generally made efforts to catch it and throw it further or faster than before. This, of course, is exactly the point. Medicine ball work provides a great plyometric workout for the upper body, and the goal is developing speed and explosive power. When we start a phase of using medicine balls a lot, people’s punches get a lot harder.

But if you’re not used to it, the DOMS (Delayed Onset Muscle Soreness) from using a medicine ball can be rather a surprise. When I first came to Wash U my main sport/activity for the previous 4 years had been JKA karate. We did a lot of kihon and kata, with the attendant “air”-punches, and my weighted, explosive upper-body strength conditioning had been limited to hitting the makiwara at the end of class, and the odd set of 20 poorly executed push-ups—and I’ll be the first to tell you that that just wasn’t enough. After my first few classes at Wash U, where we threw the medicine ball around a bit, I had the usual and expected DOMS in my quads and hamstrings, but there was also something else. It took a good couple of weeks of wondering whether I could be gearing up for a heart attack for me to realise that the odd aches and pains in my chest tended to come at predictable intervals after karate training. They were, of course, symptomatic of me actually using my pectoral muscles for the first time, in, well, ever, I suspect.

Want your female trainees to suspect they’re having heart attacks too punch like heavyweight boxers? Like the TKRI tradition of making your own training equipment? These two sites tells you how to make your very own Ball of DOMS.

Or if you’re less fond of duct-tape than we are, you can buy them pre-made here:

And finally, an alternative way to link medicine balls with pain (some bad language, don’t try this one at home):