Whether you're a fitness runner or a sub-three-hour marathoner, you’ve probably committed one or more of the ten crimes listed below. But don't worry, these errors are easy to correct. We recruited renowned coaches Dr. Jason Karp, and Dr. Matt Moran to keep you running happy and injury-free.

#10: Too Much, Too Fast

“The biggest mistake these days, especially with all of these marathon training groups, is people go from couch to the marathon way too quickly,” says Dr. Jason Karp, a running coach, elite runner, and author of Running a Marathon for Dummies. Five months isn’t long enough to build from zero to a marathon without risking injury.

The Fix: When you embark on a training program that has you running more than ever before, “do the same amount of work for two to three weeks before increasing the stress,” Karp says. That’ll give your muscles, bones, and tendons time to adapt.

#9: Going Too Hard on Easy Runs

If your easy days aren’t easy enough, your hard days will suffer. It will be more difficult to hit tempo training paces and recover from tougher efforts. The result? Muted physical gains, and a higher risk of injury.

The Fix: “Subjectively, you should be able to carry on a conversation without having to stop and take a breath,” Karp says. “You should finish the run feeling like you could’ve gone a lot longer.” Objectively, your heart rate on easy runs should be around 70 to 75 percent of your maximum.

#8: Flying Through Intervals

Interval training gets really out of hand with people because they feel like they need to break the bank, and run to exhaustion,” Karp says. “But you really want to run as slow as you can to meet the desired purpose of the workout.” Running any faster will cause unnecessary fatigue.

The Fix: If the purpose of the interval workout is to improve your VO2 max, then you should run at the speed at which you reach your VO2 max, not faster. For example, if you reach your VO2 max at a six-minute-mile pace, you should be running half-mile repeats at a three-minute pace.

So how do you find your VO2 max? Good runners can expect to hit it when running about 10 to 15 seconds per mile faster than their 5K race pace, Karp says. If you haven't run a 5K lately, aim for the slowest speed that will enable you to hit your maximum heart rate.

#7: Sabotaging Yourself

If you've put in the work before your race, your nerves may be your worst enemy. “One guy, to give himself confidence for a marathon, ran the marathon distance the week before,” Karp says. The result: fried legs that couldn’t possibly hit his goal time on race day. “People do a lot of crazy stuff because they think it’ll work."

The Fix: Get your pre-race nerves in check. Need help with that? Browse our guide to sports psychology for relaxation and visualization techniques. If you’ve been a victim of self-sabotage in the past (Chocolate cake as a pre-race meal? Heavy plyometrics days before an event?), run any out-of-the-ordinary pre-race plans by a coach or mentor.

#6: Blaming Your Shoes

“Shoes are not the reason people get injured,” Karp says. “Their training is the reason they’re getting injured.” So don’t knock the rise, cushioning, support, minimalism, or maximalism of your sneakers.

The Fix: If you're having problems with injury, see a doctor or tweak the way you're working out. And if you do trade your old sneaks for something vastly different, give your body ample time to adjust. Don’t take off on an hour-long run in Innov-8 Trailrocs when you’ve been training in Hoka One Ones.

#5: Not Refueling Properly

It’s natural not to feel hungry right after a run, but several studies have shown that muscles absorb nutrients best within 45 minutes of a workout. Skip the recovery meal, and you'll erase some of your hard-won gains.

The Fix: Eat up. According to the National Council on Strength and Fitness, a meal of protein and carbohydrates in a 3:1 ratio is optimal for post-workout muscle repair. Within one to three hours of your workout, make sure you’ve eaten about one gram of carbs per kilogram of bodyweight (that’s 272 calories for a 150-pound person) and 20 to 25 grams of protein.

#4: Starting Too Fast

“The gun goes off, you have all this adrenaline, and you start running this pace you can’t hold,” Karp says. The result: an epic meltdown before you make it to the finish line.

The Fix: “Go out at the pace you know you can sustain the whole way,” Karp says. You should know from your workouts what pace you can realistically keep up in a race. (Trying a new distance? Check out this pace-predicting calculator for an idea of what pace you can expect to maintain.) “You have to run the first half to two-thirds of the race with your head, and not with your emotions,” Karp adds.

#3: Running While Injured

It's hard to sit it out while waiting for an injury to heal. You risk setting back training and racing goals, not to mention losing a sweet endorphin rush. But whatever ails you will take longer to heal—or get worse—if you run through the pain.

The Fix: Learn to love running even when you’re not improving. “It’s not just about getting to the finish line,” says Dr. Matt Moran, founder of RUNtrix training programs. And when you do toe a starting line, “it’s smarter to get to the line healthy, excited, and confident" than it is to show up fast.

#2: Blindly Following a Plan

“Things happen. You’ll have a wedding, it’s pouring rain," Moran says. “Runners always want to make up for what they’ve missed, and they want to take that next step in the progression of their volume or intensity”—two mistakes that can easily lead to injury.

The Fix: “Write your training plan in pencil,” Moran says. “If you miss a workout, what’s done is done. Don’t make up that mileage. And if you miss several days, question whether you need to modify the volume for the upcoming week.” Don’t know exactly what you should do when you’re ready to start again? That’s where a coach or mentor comes in handy.

#1: Obsessing Over Your GPS

GPS watches can be a very useful tool, especially in helping new runners connect a certain pace to see how it feels. But new runners also expect results quickly: They want to do the four-mile run they did last week faster this week, and even faster next week. It can lead to what Moran calls “Monday Warrior” syndrome. “They don’t compete very well, but they go out and hammer their training runs,” he says.

The Fix: Leave the watch at home. At least once a week, go for a run according to how you feel. “You’re going to have ups and downs," Moran says. "Understanding the ebbs and flows of training is important."