The Dangers Of Overtraining: How Much Is Too Much?

In theory, training for peak athletic performance is simple: show up, work hard, recover, repeat on a consistent basis and watch the progress accumulate. But in practice, the process is much more nuanced — especially when it comes to steps one and two. There’s a fine line between working hard enough to impart productive stress on your body and working too hard for your body to actually get anything out of the effort.

“Stress is a good thing,” says Sarah Strong, LCSW (Licensed Clinical Social Worker) therapist and United Endurance Sports Coaching Academy-certified running coach. “Stressing the body and allowing it to adapt to those stressors is the core of athletic development.” That’s why athletes push themselves past the point of comfort in training, so that their bodies can adapt to that level of challenge and turn it into a new baseline from which the next level of growth evolves. So goes the cycle of improvement.

“But too much stress is a problem,” Strong continues. “Imagine your capacity for stress as a bucket. Every stressor adds to the bucket and too many stressors will make it overflow.” When this happens, athletes lose their ability to recover from their training and adapt to the challenge. Stress only accumulates, never dissipates.

Author on one of her favorite runs. Photo by Lina Simpson.

Without giving their bodies the chance to properly process stress, athletes get the exact opposite of the results they’re looking for. Research on the Physiological and Psychological Effects of Treadmill Overtraining Implementation links this imbalanced equation between stress in and stress out to a decline in athletic performance as well as a litany of negative health effects from musculoskeletal injuries and cardiac arrhythmias to depression and irritability.

The issue is, that’s an easy equation to mess up. There’s no one right answer for how every athlete should train in order to appropriately ride the fine line between too much stress to recover from and not enough to stimulate growth. Everyone responds to stress differently. Some can handle more without losing their ability to adapt while others have a lower threshold.

Neither one is better than the other, though. This is where well-intentioned athletes often sabotage themselves. Growth comes from finding your own sweet spot, not from continuously piling on more and more stress without regard for individuality. “The balance between load and recovery looks different for each athlete,” affirms Genevieve Harrison, professional runner for On and running coach based out of Eagle, Colorado. “The idea that more is better in ultra-running has created a craze for higher mileage, but this is detrimental to athletes in the long-term.”

T.J. David, owner of Microcosm Coaching in Carbondale, Colorado, agrees. “In my coaching practice,” he remarks, “I’ve always leaned on this training principle: the right amount of work is the least amount of work an individual can do while still growing, not the most. This is what an athlete can actually sustain long-term when taking into account the specific context of their lives. What athletes often overlook is the fact that their training doesn’t happen in a vacuum. Our bodies don’t know the difference between a run and a tough day at the office. Stress is stress. When athletes learn to purposely design their training, adventures and event goals with this in mind they can begin getting out of injury cycles and sustain long-term improvement.”

For instance, a runner might set an arbitrary goal like logging 100-mile weeks out of a genuine desire to improve … but if that’s not the best number for their unique physiology or alongside all the other stressors present in their life, then such high mileage doesn’t serve them because they’ll be too injured or exhausted to put their best foot forward (literally). The optimal amount of training for any athlete is the training they’re actually capable of completing without getting derailed by an overload of stress.

Staying on the right side of stress requires listening to what your body has to say about the amount of training that you’re doing. It’s not easy to dial things back when it might seem like everyone around you is only ever piling on more, but the decision to do so will set athletes up for more sustainable success. You’ll likely surpass those who charged ahead without heed for stress management in the end anyway.

Before athletes can heed the warning signs of overtraining, though, they need to know what cues to look out for in the first place. Just like the stress threshold, the specific signs may vary from person to person, but a few key symptoms apply to most people. Harrison has found that her body starts to talk back in the form of abnormal hormonal changes and low iron levels when she pushes past 10-15 hours of training per week or over about 90 minutes of higher intensity work within the week.

Kim Dobson, another Eagle runner who holds seven victories and the course record at the Pikes Peak Ascent, notices an elevated average heart rate over the course of a few days as her most prominent symptom of overtraining. “I also tend to get flare-ups of overuse injuries that stop me before I am ‘overtrained’ from a hormonal perspective,” says Dobson, which could be seen as a blessing in disguise in the sense that those flares are her body’s way of holding her back from causing herself further damage.

But not all the signs of overtraining are physical. Lina Simpson of Grand Junction, winner of the 2022 Ultrapalooza 50k, feels the effects of overtraining on an emotional level first. “I can really tell when I am overtraining when running starts to feel like a job,” she explains. “When I am waking up and feeling like I don’t want to go run, but also having this feeling like I need to go run, that’s how I know I need to change my approach.” Motivation ebbs and flows for everyone, but a consistent reduction in your desire to do something that usually brings you joy should raise a red flag. Low energy availability applies to mental energy too.

Show me an athlete who’s never gone overboard, though, and I’ll show you a liar. Mistakes happen, especially when someone is passionate about their sport. There’s no better asset for peak athlete performance than true love for what you’re doing. Passion only becomes a problem when it morphs into obsession and drives athletes to ignore the needs of their bodies. Do your longevity as an athlete a favor by tuning into the ways your body tries to communicate with you about your training load and when the alarms tend to sound. Allow for a little trial and error in the process. With time, you’ll settle on a general threshold that can help guide your training habits. But the real change comes down to mindset. Remember that quality almost always trumps quantity. Quality training can’t occur under excessively stressful circumstances. Hold your “why” close when self-restraint feels uncomfortable. Rest with purpose so you can train that way, too. 

Originally published in the Summer 2024 issue of Spoke+Blossom.