As the days get longer, you may consider adding distance to your runs. What kind of plan should you follow to run farther and increase your endurance but to do so safely and prevent injury?

The first rule to remember is that if you find it too difficult to complete a new distance level, do not force yourself. Many runners and running experts suggest a 10% increase—no more—every other week when you seek to increase mileage. To be even safer, add 5% every other week or 10% every third or fourth week.

  • Strategy 1: Add distance to two of your weekly runs—one short and one long. Say you currently run 20 miles a week, divided into three shorter runs and one long run, and you plan to add 10% every fourth week. When the time comes to add two miles to your weekly distance, you could split the added distance in two, adding one mile to one short run and another mile to the long run.
  • Strategy 2: Divide the added distance by four, and add one-half mile to each of your four runs.

While both are reasonable options, you cannot add to your distance indefinitely. Eventually you will reach your maximum. Injury rates go up in people who run more than 40 miles a week. If you reach the level of running 30 to 35 miles per week, do not add miles until you are extremely comfortable with that distance. Do not fall victim to “runner’s ego,” and try to run through pain.

No matter how slowly you add mileage—or even if you are a runner who is not actively adding distance—remember that rest and recovery are a runner’s best friends. Always rest the day after your longest weekly run. In addition, once you reach your maximum weekly distance, give your body a rest every few weeks and decrease your mileage by 10% or 20%, just for that week.