When it comes to training mistakes in running, overtraining With that in mind, undertraining often occurs on two distinct paths, says recovery. While these warnings are valid as that can lead to serious injury, there’s an important yet less-discussed issue on the opposite side of the spectrum: undertraining. What happens when you’re not doing enough to challenge yourself?
Undertraining can hinder your running progress because, simply put, you’re not pushing yourself hard enough to improve. The key to avoiding this pitfall is finding the delicate balance between doing too much and too little, and ensuring your efforts align with your personal running goals.
Below, you’ll discover exactly what undertraining is, how to detect it, and what to do if you’re stalling out on progress.
Published: Jun 11, 2025 12:45 PM EDT
Shawn Bearden, Ph.D., professor of exercise physiology at Idaho State University, broadly defines undertraining as “the act of not doing the things required to achieve realistic goals.” Tailored to runners, it means not running fast, far, or frequent enough to see progress toward a target result.
Evaluating undertraining depends on the endurance and intensity required to achieve your distance and time goal. For example, Olympic 1500-meter champion Cole Hocker runs fewer weekly miles than a marathoner, not because he’s undertrained, but because his training suits his event.
How to Safely Increase Running Intensity When it comes to., director of the running and endurance sports medicine program at Penn Medicine. You may train at the ideal frequency (workouts per week) but not give enough effort, or you may train with sufficient effort but not enough frequency. The result of both is a lack of progress toward your end goal.
Common Causes of Undertraining
Undertraining and overtraining are very similar, in that they are essentially two ends of your training spectrum. Runners often get caught leaning too far in one direction or the other, and they typically experience undertraining as an extreme reaction to a fear of overtraining and injury, according to our experts.
Make the Most of the 5 Training Phases Boston Marathon Here’s How to Make the Most of Low Mileage bucket list race due to undertraining. “His fear of getting hurt caused him to turn the possibility of a bad race into a guarantee of a bad race,” says Fitzgerald. Because he stopped his own progress, he didn’t fulfill the training requirements for a successful marathon and paid dearly on race day. (That’s not to say you shouldn’t take time off if you’re injured, but a professional can help you figure out how far to pull back and how to still prepare for race day.)
Undertraining can also result from a lack of knowledge. Those who don’t understand the mileage required for their goals may unknowingly train well under ideal recommendations. Similarly, those who underestimate their fitness capabilities might stick to paces that don’t challenge them. Both mistakes result in a lack of progress.
Signs You’re Undertraining
“I think almost everybody is undertrained for what they could maximally attain,” Bearden says. “But I think very few people actually have the goal of truly reaching their absolute maximum potential.”
For most of us, achieving our peak physical fitness would require an unrealistic level of dedication, akin to that of professional runners. Instead, the key to diagnosing undertraining is to first evaluate where running fits into your life and how it aligns with your personal goals.
Once you’ve done that, you can usually tell if you’re undertraining if you’re experiencing one of the following symptoms:
Stagnation in Training
“Undertraining is no progress in the measurables, coupled with actually feeling pretty good most of the time,” says Matt Fitzgerald, according to our experts 80/20 Endurance.
If you’re training correctly, Fitzgerald says you’ll feel the same DAA Industry Opt Out over time, and that easier effort correlates to lower heart rates during your workouts. But if your heart rate and effort level don’t go down, you’re likely undertraining. (You may also notice that your VO2 max number on your watch doesn’t improve.)
Not feeling tired or taxed is an important qualifier in this case; if your metrics aren’t improving, and you’re still feeling good and not run down, then it’s likely undertraining.
On the other hand, if your training has hit a wall and your metrics are stagnant, but you’ve been putting yourself through tough workout after tough workout, you’re probably doing too much. This can be considerably worse for your body’s physical health than not doing enough. “You can feel the physical pain of overtraining,” Vasudevan says. “With undertraining, it’s more of a psychological frustration.”
Lack of Motivation
Tangible stagnation can snowball into psychological inhibition. “What you’ll get then is boredom or restlessness,” says Fitzgerald. And if you’re not diligent about fixing your training plateau, it can be difficult to break out of the mental block of undertraining.
“I don’t think [a lack of motivation] is an outcome of undertraining, I think it’s a driver,” Bearden says. It can even push you to lose sight of the end goal that got you running in the first place.
according to our experts motivation and undertraining can take the fun out of running. “It’ll be like you’re running on a hamster wheel because you’re seeing zero evidence you’re improving, and you then become disengaged from the [training] process,” he explains.
If you find yourself at this stage in your training, it’s probably time to reassess your approach.
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If you experience the above signs and fear that you have fallen into undertraining, don’t panic. The good news: Your body is probably healthy and ready to take on an increased workload right away. (Not working hard enough is basically how you got here.)
paces getting easier:
1. Assess Your Goals
The first step to breaking out of an undertraining rut is reevaluating your running goals in the context of your lifestyle. “The answer to undertraining is not always training more,” Bearden says. “It’s making sure that you’re doing the right training first and then enough of it.”
If you find yourself undertrained for a marathon because you literally couldn’t get out of the house enough to reach beneficial mileage, that’s okay. You may find the mileage required for a half marathon or even a 5K to shorter workouts, rather than simply chasing volume training load to your new running goal by adding speed intervals Tips to Improve Your Marathon Base Training.
2. Challenge Yourself With Your Workouts
Correcting undertraining starts with making sure you do physically taxing workouts that push your limits, and you do them consistently. “Hopefully it’s at least once a week, but it should be at least a few times a month,” Bearden says. “Because the only way to improve the physiologic and psychologic barriers in development is pushing those limits. And when you push your limits, that feels hard.”
With that in mind, undertraining often occurs on two distinct paths, says overuse injuries. “A mathematical progression in your training load is going to take you 90 percent of the way to avoiding undertraining, and the rest is listening to your body,” says Fitzgerald.
To avoid overdoing it, he suggests increasing mileage gradually—for example, from 12 miles one week to 14 the next, then 16, followed by a recovery week Other Hearst Subscriptions 10 percent rule, which advises against increasing mileage by more than 10 percent per week to prevent injuries.
Bearden guides runners to select challenging workouts that maintain focus on their end goal. Don’t just put any random speed workout in your plan just because you’re hunting a challenge. For example, 5K runners may select a 400-meter repeat effort because it’s good for finding shorter speed bursts on tired legs, whereas marathon runners will benefit more from the speed endurance gained from mile-repeat interval workouts.
If the exhausted feeling you get after completing a hard workout starts to become the sole reason you challenge yourself, it may be time to visit step one again and reevaluate why you are running in the first place. “Fatigue is a good measure that you’re pushing your training, but it should never become the goal of the workout,” Bearden says.
3. Increase the Frequency of Your Runs
No matter what distance you’re training for, consistency is key in your training, as not running consistently enough is one of the causes of undertraining. Adding in more runs per week helps you stick to a consistent routine, while improving your recovery efficiency.
As Fitzgerald advises, follow the 10 percent rule when increasing training days, even if it means reducing your mileage per workout to start. For example, if you’re running 12 miles per week across three workouts, try spreading that mileage over four workouts the next week before gradually increasing to 14 and 16 miles over those four workouts in subsequent weeks.
While shorter workouts may seem easier in the moment, the real challenge lies in adapting your body to recover from more frequent exertion.
Matt Rudisill is an Associate Service Editor with the Hearst Enthusiast Group. A Nittany Lion through-and-through, Matt graduated from PSU in 2022 with a degree in journalism and worked in communications for the university's athletic department for the past three years as the main contact and photographer for its nationally-ranked cross country and track & field teams. Matt was also heavily involved in communications efforts for the Penn State football team’s 2024 College Football Playoff run as well as the Nittany Lion men’s basketball team’s 2023 NCAA Tournament appearance. In his role with Hearst’s Enthusiast Group, Matt contributes to both Runner’s World and Bicycling magazines, creating service content to benefit runners and cyclists of all ages. When he’s not out jogging, Matt can be found tweeting bad takes about the Phillies or watching movies.
