What It Means?
The 10 percent rule refers to the number of miles a runner should increase their weekly mileage each week while training in order to avoid injury and prepare efficiently. For example, if you run 20 miles during your first week of training, the rule asks you not to run more than 22 miles the following week – TOTAL! That means keeping your weekly mileage at 20 miles for week two, or simply adding 2 more miles somewhere during the week. Typically, these miles are added to days where speed is not the goal (i.e. long runs, weekday recovery pace runs, etc.).
Why It Matters?
The most common injuries for runners tend to occur because of overuse while training “too much too soon.” When initiating the first few weeks of training, the body goes through multiple adaptations within the cardiovascular, neurological, and muscular systems. Of these areas, the muscular system takes the longest to adapt (sometimes 4-6 weeks for tendons, ligaments, muscle strength, etc). That means, your cardiovascular system may feel great, and your lungs say “Hey, you can probably run 8 miles today – you feel great!” However, if you’ve only been training for 2-3 weeks at 20-25 miles/week, your muscles/joints may not feel the same, and they don’t speak up until its too late. Now your darn patellar tendon is yelling at you every time you go down the stairs. How frustrating!
What Do I Think?
This rule RARELY fits the training needs for most individuals, and it is very dependent on factors such as your base fitness level. For example, if you have never run before and your goal is to train for a 5K in 3-4 months, the first couple of weeks will be focusing on increasing the time you spend running more than increasing your weekly miles (i.e. walk-run intervals over 30 min —> running continuously for 30min). However, if you have been running marathon distances for years and your goal is to increase your time to qualify for Boston, then adding more than 5 miles to a 50 mile week probably wont lead to injury, especially if you typically run 5-6 days/week consistently.
Need More Info?
If you don’t know what your base-level of fitness is prior to starting a training cycle and you are worried about injuries, be sure to reach out to your physical therapist or running coach to ensure you stay injury free while obtaining those running goals!
By: Sarah Ceschin, PT, DPT