"Of course, if you do 12 exercises for 30 seconds each, with 10 seconds in between as recommended, that’s eight minutes, not seven. But they’re mostly English majors at the NYT."
The real answer is 7 minutes 50 seconds since there are 12 exercises but only 11 "in betweens", but Instapundit is only a lawyer, so you can't really expect arithmetic accuracy from him either.
Update: I sent an email pointing out the error to Instapundit and he responded: "I always start with a ten second rest period." No smiley face emoticon or anything - sounds like a damn lawyer, doesn't it? :-)