So I splurged just a little and got a new watch, one that monitors your heart rate. It cost $105 (¥12,200), what I guess is pretty good price at that, for what it is. I went to Victoria Sports yesterday, but all they had was one cheap-o watch that looked dodgy at best. Today I went to Yodobashi’s watch shop, and they had better variety, and better quality for the money. The one I got is a Casio (pretty much every watch I’ve had since I first got wristwatches has been a Casio), and has all the features I need.

It replaces the last watch I had, which conked out a few years ago, and I’ve done without for some time because I just used my cell phone clock instead. But now that my foot is more or less healed, I’m starting up on what I hope will be a consistent and building exercise program, and so having a heart monitor was a big plus. This one monitors your heart rate by use of a chest strap that sends the data to the watch by a radio signal. I had heard about watches like this, but had never looked at them. After testing it, it seems to work pretty well.

The watch also happens to match my other wants–it has a stopwatch, timer, alarms, an easy-to-change world clock, and most of all, the thing is not a huge chunk of plastic. Despite its relatively slim form, however, it still feels like it sticks out too much, especially under my jacket cuffs. But it might only feel that way because I haven’t worn a watch in over two years.

Not having exercised much in the past, I did not know about the Karvonen Formula. It’s a calculation that takes your age and your resting heart rate (the rate you experience before getting out of bed in the morning) and determines your target heart rate zone, or “training zone,” which is 60% to 80% of your maximum heart rate (which I presume is just before your heart becomes over-stressed). Maintaining that zone during exercise is best for cardiac exercise and fat burning, which is what I need right now. I’ve already lost 12 kilos off my top weight by diet alone, but I need to lose another ten or so to get into a healthier range.

After having been more or less immobile for three and a half months with a broken foot, I am way out of shape. Not that I was in great shape before, but now my legs start getting shaky if I walk up four or five flights of stairs. That exertion doesn’t get me winded–it just saps all the energy from my legs and leaves me weak-kneed. What better time to start an exercise program and try to make it stick?

Knowing the rate also helps me pace myself for longer exercise. I have an aerobic training machine, one that mimics cross-country skiing motions, with arm sticks and all. I started exercising on that, and found I could not go on for more than a few minutes before I couldn’t take any more. With the watch monitoring my heart rate (sitting on the handlebar in front of me so I could keep an eye on it), I was forced to artificially slow my pace to keep my heart rate in the zone–and doing that helped me handle the workout better without tiring out, and allowed me to continue going for a lot longer. Forgive me if any of this sounds obvious or too fundamental; I haven’t exercised outside of normal activity for some time. In high school, I was in great shape, having a weight training and aerobics-centered PhysEd course. But back then, we just worked out–no science, and no timing aside from simply going on until the end of the period.