The Truth About 6 Common Marathon-Training 'Rules'

When you sign up to run a marathon, you’ll start hearing and reading all kinds of advice about things you must do during your training. From what you eat to the number of miles you rack up each week, there are certain “rules” that seem necessary if you want to be successful come race day. But many of these seeming gold standards of race prep aren’t necessary after all, says Jeff Gaudette, the Boston-based owner of RunnersConnect.net. So before you go and schedule your long runs or plan pasta dinners, read on for the latest take on common training tips.

RULE 1: NEVER INCREASE YOUR MILEAGE BY MORE THAN 10 PERCENT FROM WEEK TO WEEK.

MYTH

This is a very common rule of thumb to prevent injury while adding mileage. But is it necessary? Not so much. Studies have shown that runners who ramp up their mileage more quickly don’t get hurt more frequently than those who stick to the 10-percent standard. “That being said, it’s not a bad rule to follow,” says Gaudette. “It comes in handy because it’s a conservative way of increasing your mileage. Most runners could increase their miles by more than 10 percent and not get hurt, but it’s better to be safe than be too aggressive and risk injury.”

RULE 2: YOU SHOULD DO YOUR LONG RUNS AT A PACE 60 TO 90 SECONDS PER MILE SLOWER THAN YOUR GOAL RACE PACE.

FACT

Most people go too fast on their long runs, says Gaudette; he actually suggests slowing down to 90 seconds or even two minutes per mile slower than your goal race pace for long runs. “When we do long runs, we’re trying to improve our aerobic development, and that peaks between 65 and 70 percent of your 5K pace,” he explains. “Once you start running faster than that, you’re getting diminishing returns. By running slower, you’re improving more than if you were running faster. You’re working the right energy system.” Plus, he says, when you run faster during runs that are supposed to be slow and relaxed, it puts extra stress on your tendons and ligaments, upping the likelihood you’ll get hurt.

RULE 3: MARATHONERS SHOULD AVOID STRENGTH TRAINING BECAUSE BULKING UP WITH MUSCLE WILL SLOW YOU DOWN.

MYTH

First of all, your chances of gaining much muscle while you’re training for a marathon is slim, says Gaudette; you’d have to consume a large surplus of calories, which is tough to do when you’re burning a lot of calories on your runs. Plus, he says, “if you lose fat and add muscle, it’d help you be a more efficient runner.” He recommends strengthening your core—abs, glutes, hamstrings, hip flexors, and lower back—to help you go the distance and stay ache-free.

RULE 4: YOU SHOULD RUN AS CLOSE TO 26 MILES AS POSSIBLE BEFORE RACE DAY.

MYTH

You might feel more mentally prepared to take on 26.2 miles if you log 22, 24, or even 26 at once before the day of your marathon. But doing so isn’t actually advisable. When you run longer than two and a half or three hours, you open yourself up to injury, says Gaudette, because your big muscle groups get tired. “For example, your glutes are a major muscle group for providing power,” he explains. “As they get tired, your body will push that energy to your calves, and when you start using your calves more, it can lead to injuries like Achilles tendonitis and plantar fasciitis.” Though many training plans have a 20-mile run on the calendar, Gaudette says most runners can get away with a longest run of 16 to 18 miles before race day.

RULE 5: YOU’VE GOT TO DINE ON A PRE-RACE PASTA DINNER.

MYTH

The tradition of downing a plateful of pasta the night before your race stems from the fact that endurance runners need carbohydrates—they’re important to ensure your body has a full tank of glycogen (your muscles’ go-to energy source) when you start running. That part of the rule is still true, but pasta doesn’t have to be on the menu. “Sweet potatoes, rice, and oats are all high-quality carbohydrates that are good to consume the day before your race,” says Gaudette. You don’t necessarily need lots of carbs the night before a long run during training, he notes, but it is important to have your pre-race dinner at least once during training as practice to make sure it’ll work well for your body for the actual marathon.

RULE 6: TRY NOTHING NEW ON RACE DAY.

FACT

This advice goes for every part of your race—from the shoes you wear to the meal you eat beforehand to the flavor of gels you snack on for mid-run fuel. You don’t want to throw your body a curveball during the race when you don’t know how it will respond to something new. The one exception, says Gaudette, is if you have no choice to use something new, like if you forget to pack your favorite socks, it’s of course better to buy another pair than to go without. “There’s a chance that nothing will go wrong if you switch something up,” he says. “But given all the time and effort you’ve put into preparing for this race, this one day, it’s best to eliminate all the unknown factors that you can to help ensure your best performance.”