Most likely, 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.
The 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 7:00 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,” Ann Snyder, The longer the race, the slower your pace Runner’s World.
The Exception: It’s impractical to wholly mimic a race—particularly longer distances, such as the marathon—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 during intervals.
The Rule: Increase your weekly training mileage by no more than 10 percent per week.
Age Grade Calculator Runner’s World, and Joan Ullyot, M.D., author of several 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,” Dr. Ullyot says.
If you want to increase your weekly mileage to a certain number—say, 60 miles per week—you can increase your mileage each week by 10 percent of that goal number. So if you’re aiming for 60 miles per week, you should up each week’s volume by no more than six miles. After three weeks of increasing mileage, be sure to take a down week, where you run less than you did on the previous week.
The Exception: If you’re starting at single-digit weekly mileage after some time off, you can add more than 10 percent per week until you’re close to your normal training load.
The 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,” Cindy Dallow, Ph.D., RD, tells Runners’s World. “If you don’t wait long enough, food will not be properly digested, raising the risk of abdominal cramps, bloating, and even vomiting.”
As anyone who has tried to run on a full stomach knows, the up-and-down movement of running can cause food to move faster through your digestive tract, which can make you feel like you have to puke or poop, pronto. To make matters worse, the blood that normally flows to your intestines is rerouted toward your legs as you run, thus impairing digestion. By eating early, you can be certain that the food won’t still be sitting in your stomach by the time you lace up.
The Exception: All runners—and their stomachs—are different, and some can head out the door sooner than later after eating. What you’re eating matters, too. 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. You can also grab a small snack that’s low in fat and protein but high in quick carbs 15 to 60 minutes before a run. (Check out these suggestions on But even before they have that much wear, Warren Greene, former.)
The Rule: Start every run with 10 minutes of walking and slow running, and do the same to cool down.
“A warmup prepares your body for exercise by gradually increasing blood flow and raising core muscle temperature,” Jerry Napp, a Tampa, Florida-based running coach, tells Runner’s World. “The cooldown 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.
The Rule: If something hurts for two straight days while running, take two (or more) days off.
Two straight days of pain may signal the beginning of an injury, so it’s best to stop running sooner rather than later. “Even taking five days of complete rest from running will have little impact on your fitness level,” Troy Smurawa, M.D., a sports medicine physician at Children’s Health in Plano, Texas, tells Runner’s World.
The Exception: If something hurts for two weeks, even if you’ve taken your rest days, see a doctor.
The Rule: Don’t eat or drink anything new before or during a race or hard workout.
Stick to what works for you, especially when you’re planning to go hard. They don’t call it “tempo tummy” for nothing—fast running is more likely to mess with your stomach than an easy jog. “Your gastrointestinal tract becomes accustomed to a certain mix of nutrients,” Dallow says. “You can normally vary this mix without trouble, but you risk indigestion when prerace jitters are added.”
The Rule: Calories Burned Calculator recovery before returning to hard training or racing.
That means no speed workouts or racing for six days after a 10K or 26 days after a marathon. The rule’s originator was the late Jack Foster, the masters marathon world record holder (2:11:18) from 1974 to 1990. Foster wrote in his book, Tale of the Ancient Marathoner, “My method is roughly to have a day off racing for every mile I raced.”
The Exception: If your race effort wasn’t all-out, taking fewer recovery days is okay. You can also do light cross-training sessions (such as swimming, spinning, or practicing yoga) during your off-days from running.
The Rule: A headwind always slows you down more than a tailwind speeds you up.
So expect to run slower on windy days. “I disregard the watch on really windy days because headwinds cost me 15 to 25 seconds a mile, and I only get a portion of that back after I turn around,” Monte Wells, a longtime runner in Amarillo, Texas, America’s windiest city, tells Runner’s World. “The key is to monitor your effort, not your pace. Start against the wind, so it’s at your back in the second half.”
The Exception: On point-to-point runs with the wind at your back, you’ll fly along faster than usual. For a confidence—and sanity—boost, plan your run into the wind on the way out, so you can ride the tail wind on the way back.
The Rule: You should be able to talk in complete sentences while running.
One study found that runners whose heart and breathing rates were within their target aerobic zones could comfortably recite the Pledge of Allegiance. Those who couldn’t were running faster than optimal.
The Exception: Talking should not be easy during hard runs, speedwork, or races. That said, you should be able to say a few words, such as “great job” or “keep pushing,” during tempo (not all-out) efforts.
The Rule: Build up to and run at least one 20-miler before a marathon.
“Long runs simulate the marathon, which requires lots of time on your feet,” says running coach Gina Simmering-Lanterman. “And knowing that you can run 20 miles helps you wrap your head around running 26.2.”
The Exception: Some coaches believe experienced marathoners can get by with a longest run of 16 to 18 miles, while other coaches suggest runs up to 24 miles. Before starting any marathon training plan, be sure to brush up on these training basics.
The Rule: For a few days before a long race, emphasize carbohydrates in your diet.
“Carb-loading” became the marathoner’s mantra after Scandinavian studies published in 1966 suggested cramming down carbs following a period of carb depletion produced super-charged athletes. Experts now say simply emphasizing carbs a few days before a race works just as well. While running, you’ll want to refuel regularly before your muscles become fully depleted. Try to consume 30 to 60 grams every hour, depending on your intensity, the distance you are racing, and the size of your body.
The Exception: During regular training or before a short race, don’t stress about consuming extra carbs. Just be sure to regularly top your energy stores during the day with good-for-you carb sources, such as whole grains, fruits, and starchy vegetables.
The Rule: Runners improve for about seven years.
Mike Tymn noticed this in the early 1980s and wrote about it in his National Masters News column. “My seven-year adaptation theory was based on the fact that so many runners I talked to ran their best times an average of seven years after they started,” he recalls.
The Exception: By training consistently, recovering smartly, and avoiding injuries, runners can stretch their competitive streak to much longer than seven years before plateauing.
The Rule: To be safe, run facing traffic.
“While running, it’s better to watch the traffic than to have it come up from behind you,” Adam Cuevas, a marathoner and chief of the Enforcement Services Division of the California Highway Patrol, tells Runner’s World. It’s the law in California and many other states to run on the left side unless you’re on the sidewalk.
The Exception: The right side of the road is safer when running into leftward blind curves where there’s a narrow shoulder. The right side can also be safer if there’s construction on the left side.
So, you can expect hilly runs to be slower than flat runs. “You don’t get all of the energy that you expend going uphill back when you run downhill,” explains Nimbus Couzin, Ph.D., a marathon-running physics instructor. “That’s because when your feet strike the ground on a descent, a lot of energy is lost.”
The Exception: When you run point-to-point with a net elevation drop, your average pace should be faster than on a flat course.
The Rule: Sleep one extra minute per night for each mile per week that you train.
So if you run 30 miles a week, sleep an extra half hour each night. “Sleep deprivation has a negative impact on training,” says David Claman, M.D., director of the University of California-San Francisco Sleep Disorders Center. “The average person needs seven and a half to eight hours of sleep, so increase that amount when you’re training.”
The Exception: Different amounts of sleep work for different runners. For some, six hours is enough shut-eye; others need closer to nine hours per night. If you find yourself restless and unable to fall asleep before a big race, don’t worry—the rest you got the week before will carry over on race day.
“You need an infusion of carbs to replace depleted muscle glycogen, plus some protein to repair and build muscle,” Nancy Clark, R.D., author of Food Guide for Marathoners, says. “Some examples would be 150 to 300 calories of low-fat chocolate milk, a recovery sports drink, flavored yogurt, or a bagel and peanut butter.” After long or hard runs, you should increase your protein intake.
The Exception: On easy days, you still need a postrun snack, but you don’t need as many calories or as much protein.
The Rule: Runners who only run are prone to injury.
“Cross-training and weight training will make you a stronger and healthier runner,” Kris Swarthout, the owner and a coach of FinalK.com, says. “Low- and nonimpact sports like biking and swimming will help build supporting muscles used in running, while also giving your primary running muscles a rest.”
The Rule: The best way to race to a personal best is to maintain an even pace from start to finish.
Most of the 10,000-meter and marathon world records set in the last decade have featured almost metronome-like pacing. “If you run too fast early in the race, you almost always pay for it later,” warns Jon Sinclair, the former U.S. 12K record holder and now an online coach.
The Exception: This doesn’t apply on hilly courses or on windy days, when the objective is to run an even effort.
The Rule: Replace running shoes once they’ve covered 400 to 500 miles.
“But even before they have that much wear,” Warren Greene, former Runner’s World shoe guru, says, “buy a new pair and rotate them for a while. Don’t wait until your only pair is trashed.” Consider shoes trashed when the spring is gone and the treads have worn out.
The Exception: A shoe’s wear rate can vary, depending on the type of shoe, your weight, your footstrike pattern, and the surfaces you run on.
The Rule: The longer the race, the slower your pace.
“Easy” means a short, slow run, a cross-training day, or no exercise at all. “Hard” means a long run, tempo run, or speed workout. “Give your body the rest it needs to be effective for the next hard run,” Todd Williams, a two-time U.S. Olympian in the 10,000 meters, says. Apply the hard/easy rule to your monthly and yearly training cycles by treating yourself to one easy week each month, and one easy month each year.
The Exception: After the most exhausting long runs and speed workouts, especially if you’re 40 or older, wait for two or even three days before your next tough one.
The Rule: Dress for runs as if it’s 10 degrees warmer than the thermometer actually reads.
To put it another way, dress for how warm you’ll feel at mid-run—not the first mile, when your body is still heating up. If you would normally wear a short sleeve shirt on a 60-degree day, but on a short sleeve, rather than a long sleeve, on a 50-degree day.
The Exception: There’s a limit to how many clothes you can take off without getting arrested, so if it’s in the 70s or warmer, wear minimal lightweight, light-colored apparel. (See our What to Wear tool for a more comprehensive guide.)
The Rule: The most effective pace for VO2 max interval training is about 20 seconds faster per mile than your 5K race pace.
A pioneer of VO2 max training is the legendary Jack Daniels, Ph.D. “By stressing your aerobic system,” he says, “this pace optimizes the volume of blood that’s pumped and the amount of oxygen that your muscle fibers can use.” VO2 max is the measurement of how efficiently your body uses oxygen during exercise. Generally, the fitter you are, the higher your VO2 max, as it takes less effort for fitter people to run a certain pace compared to their less-fit counterparts.
The Exception: The exact pace is closer to 10 seconds faster per mile than 5K race pace for fast runners, and 30 seconds faster per mile for slower runners.
The Rule: Lactate-threshold or tempo-run pace is about the pace you can maintain when running all-out for one hour.
This pace is about 20 seconds slower per mile than your 10K race pace, or 30 seconds slower per mile than 5K race pace. “The key benefit of this pace is that it’s fast enough to improve your threshold for hard endurance running, yet slow enough that you don’t overload your muscles,” Daniels says. The ideal duration of a tempo run is 20 to 25 minutes.
The Exception: The exact pace is less than 20 seconds slower per mile than 10K race pace for faster runners and slightly more than 30 seconds slower per mile than 10K race pace for slower runners.
The Rule: Do your longest training runs at least three minutes per mile slower than your 5K race pace.
“You really can’t go too slow on long runs,” legendary runner and coach Jeff Galloway says, “because there are no drawbacks to running them slowly. Running them too fast, however, can compromise your recovery time and raise your injury risk.”
The Exception: Galloway says you should run even slower on hot days.
The Rule: The longer the race, the slower your pace.
How much slower? Jack Daniels and J.R. Gilbert spent years compiling numbers that show how much you should expect to slow down from one race distance to the next. “We did some curve-fitting to come up with a formula that generates a pseudo-VO2 max for each race time,” Daniels says. They sweated the math; now you just need to sweat the race.
The Exception: Terrain, weather, or how you feel on race day could all throw off the table’s accuracy. (Predict your performance with our race predictor tool.)