Our latest podcast is called “What’s the ‘Best’ Exercise?” (You can subscribe to the podcast at iTunes, get the RSS feed, or listen via the media player above. You can also read the transcript; it includes credits for the music you’ll hear in the episode.) Exercise is always on a lot of people’s minds around this time of year, what with all those resolutions just waiting to be broken …

By “best,” we really mean “most efficient,” since people who don’t exercise — and that’s roughly 80 percent of us — often blame lack of time. (The American College of Sports Medicine recommends about thirty minutes of moderate exercise most days of the week; here are its guidelines.)