Note to readers: Whether for athletics or age, Americans from teenagers to baby boomers are trying to get an edge by illegally using anabolic steroids and human growth hormone, despite well-documented risks. This is the first of a two-part series.

WASHINGTON – With steroids easy to buy, testing weak and punishments inconsistent, college football players are packing on significant weight – 30 pounds or more in a single year, sometimes – without drawing much attention from their schools or the NCAA in a sport that earns tens of billions of dollars for teams.

Rules vary so widely that, on any given game day, a team with a strict no-steroid policy can face a team whose players have repeatedly tested positive.