In most cases, these rules started out as a lightbulb over one runner's head. After a while, that runner told a few running buddies (probably during a long run), word spread, and before you know it, coaches were testing it, sports scientists were studying it, and it evolved from idea to theory to accepted wisdom. Along with each of the rules we present, however, we list the exception. Why? Because, as you also learned in grade school, there's an exception to every rule.
More: A Few Rules To Run By
1. The Specificity Rule
The most effective training mimics the event for which you're training.
This is the cardinal rule of training for any activity. If you want to run a 10K at a seven-minute-per-mile pace, you need to do some running at that pace. "Runners are best served by running at goal pace and in the expected environment of that race," says Ann Snyder, Ph.D., director of the human performance lab at the University of Wisconsin-Milwaukee.
The Exception: It's impractical to wholly mimic a race—particularly longer distances—in training because it would require extended recovery. So, when doing race-specific training, keep the total distance covered shorter than the goal race, or run at your race pace in shorter segments with rest breaks (interval training).
2. The 10-Percent Rule
Increase weekly training mileage by no more than 10 percent per week.
Joe Henderson, the first editor of Runner's World, and Joan Ullyot, M.D., author of three women's running books, first popularized the 10-percent prescription in the 1980s. "I noticed that runners who increased their training load too quickly were incurring injuries," says Dr. Ullyot.
The Exception: If you're starting at single-digit weekly mileage after a layoff, you can add more than 10 percent per week until you're close to your normal training load.
3. The 2-Hour Rule
Wait for about two hours after a meal before running.
"For most people, two hours is enough time for food to empty from the stomach, especially if it's high in carbohydrate," says Colorado sports dietitian and marathoner Cindy Dallow, Ph.D. "If you don't wait long enough, food will not be properly digested, raising the risk of abdominal cramps, bloating and even vomiting."
The Exception: You can probably run 90 minutes after a light, high-carb meal, while you may need up to three hours after a heavy meal that's high in protein and fat.16 Healthy Pre-Run Snacks That Won't Derail Your Diet
4. The 10-Minute Rule
Start every run with 10 minutes of walking and slow running, and do the same to cool down.
"A warm-up prepares your body for exercise by gradually increasing blood flow and raising core muscle temperature," says Jerry Napp, a Tampa Bay running coach. "The cool-down may be even more important. Stopping abruptly can cause leg cramps, nausea, dizziness, or fainting."
The Exception: It takes less than 10 minutes to rev up on warm days.