How smoking helps marathoners (and more bad research)

My Jockology column in this week’s Globe and Mail takes a look at three questions:

1. How do cigarettes help marathoners run faster?
2. Why does eating red meat cause car crashes?
3. Does caffeine cause breast cancer?

In each case, I analyze studies that seem to “prove” these surprising findings, and identify the errors (cherry-picking data, inadequate statistical adjustment, and fishing expeditions) that lead to these conclusions. Basically, it’s a “how to assess medical research” primer. Read the whole thing here.