“The treadmill is, in fact, an appropriate metaphor. By some estimates, about 40 percent of people who buy home exercise equipment later say they ended up using it less than they’d expected. How hard we push ourselves in a given workout matters, of course, but I think the bigger impediment to progress is that sometimes we stop working it altogether. As any coach or athlete will tell you, consistency of effort over the long run is everything. How often do…
