I am in a long, slow recovery from a sacroiliac joint sprain. I’ve just started being able to do more exercise than mild physiotherapy exercises, after almost nine months. I have to be careful, but I can do it. I am in the worst shape of my life, and generally I dislike it. The one nice thing, though, is how little I have to work to reach an aerobic heart rate.

In my normal shape, for example, bicycling is not a good choice for an aerobic workout. I have to push uncomfortably hard just to get to my minimum, low-level aerobic heart rate. [Which is somewhere around 108 beats per minute–60% of an estimated maximum of 180, since I can’t yet push hard enough to discover what my actual max is.] Now I can hop on my bike and hit an aerobic zone within a minute of riding gently. Pretty nice!