Best worst choice: fast-tracked marathon training

The gist:

Ideally, you'd train for a marathon over about three months. But if you can run an easy 12 miles, you can prepare safely in just eight weeks with a few adjustments to your plan, says New York City-based Precision Run coach Elizabeth Corkum.

Expert insight:

The biggest difference between a regular plan and a fast-tracked one is speed work. You should skip it entirely on such a short timeline, Corkum says. And with only two months to prep, your mileage should never increase by more than 10 percent week over week.

The bottom line:

Never train with fewer than eight weeks to go, Corkum says. It will only up your risk of developing common injuries like IT band syndrome, stress fractures, shin splints, runner’s knee, and plantar fasciitis.