What is Overtraining Syndrome?

No pain, no gain.
Push through it.
What doesn’t kill you makes you stronger.
Winners never quit; quitters never win.

Popular culture is full of such sayings, popular maxims urging people to persevere even under the most adverse conditions. And while such truisms are usually inspiring, working through pain can sometimes be dangerous. Minor injuries can worsen, and other parts of the body may compensate, potentially leading to new injuries. In other words, too much of a good thing — exercise and sports — can actually backfire.

Sports doctors are seeing more cases of overtraining syndrome (OTS), a condition that once only affected elite athletes and endurance enthusiasts. But as people grow more interested in intense workouts and extreme races, OTS is increasingly affecting recreational athletes.

While there are no exact figures on OTS among the general population, there are some educated guesses.

Among non-professional athletes who train intensively for endurance events such as swimming, cycling, or running, an estimated 30% may experience overtraining at some point.

OTS occurs “when you work your body beyond its capability to recover,” says Kristopher J. Paultre, M.D., a family medicine and primary care sports medicine specialist with the UHealth Sports Medicine Institute. “It happens when you exercise too frequently or too intensely without giving your body enough time to rest and recover.”

However, there is a big difference between the elite athlete’s experience with overtraining syndrome and that of the weekend warrior.

Pro competitors and college and high school athletes are typically supervised by a health care team that follows a structured recovery plan that includes proper nutrition, hydration and rest.

“They are cognizant of the fact that these athletes put their bodies under a lot of strain,” Dr. Paultre says. “Whereas the lay person doesn’t have that help and may not recognize what is happening to their body.”

In other words, the average person does not have access to a team nutritionist, psychologist, physical therapist, or sports physician. The average individual may not recognize persistence fatigue as a symptom of a potentially serious issue nor understand the importance of balancing intense workouts with adequate rest.

The recreational athlete may, in fact, confuse overtraining with normal soreness. “They may think they have to work through it and in the end overdo it,” Dr. Paultre says.

OTS has different stages, or grades, defined mainly by symptoms.

These can range from mild aches and pains to severe manifestations that affect a person both physically and mentally. The most notable signs of overtraining are: chronic fatigue, persistent muscle and joint soreness that doesn’t resolve with rest, frequent injuries, disrupted sleep patterns, hormonal imbalances, and lack of motivations. In some cases, a person may develop depression or anxiety, and his performance in the sport either stalls or actually worsens.

Overtraining syndrome isn’t always a progressive condition. A weekend athlete may display more severe symptoms without suffering from the early symptoms. “It affects different people in different ways,” Dr. Paultre says.

It shouldn’t be confused with overuse injuries, though the two are related.

An overuse injury, such as tendinitis, stress fractures, and shin splints, is caused by repetitive motion and poor technique. The pain builds over time and is limited to a specific joint, muscle or bone.

Overtraining, on the other hand, is a systemic condition affecting the whole body as well as the mind.  A person with OTS can have an overuse injury, but not all who suffer from overuse injuries develop OTS. In the severest OTS cases, “the body begins to shut down,” Dr. Paultre says, adding that if left untreated, it can take months to recover and even result in difficulties with concentration, mental fog, immune suppression, insomnia and cardiovascular strain.

One 2025 case study examining three types of runners with OTS (professional, competitive, and recreational) found that even the recreational athlete displayed severe symptoms, including endocrine and immune disruption.

Dr. Paultre and other specialists use a combination of medical tools to reach an OTS diagnosis.

This includes:

• heart rate tracking
• brain scans
• blood tests
• psychological questionnaires

Researchers have developed something called the EROS scale to analyze symptoms and identify OTS more accurately.  EROS actually consists of three diagnostic scores based on observable clinical signs, biochemical tests, and other measures of body composition.

 For Paultre, “when OTS is on my radar, 90% of the diagnosis is based on the patient’s clinical history.”

Treating OTS can be tricky.

Not everyone wants to rest for weeks or months. “Some people can’t stop [exercising] even when you tell them they have to take off. Active individuals want to stay active. If they take time off, they feel they’re staying in place,” Dr. Paultre says.

That’s why he recommends “active recovering,” which means participating in restorative practices that help the body and mind heal. This includes prioritizing sleep, doing gentle low-intensity activities like walking or yoga, focusing on nutrition to support hormonal balance, participating in physical therapy, and addressing emotional fatigue with therapy or mindfulness exercises.

Of course, the ideal situation is to prevent overtraining altogether.

Prolonged rest between intense workouts is essential, as is eating a nutritious diet that matches caloric intake with your body’s needs. Finally, Dr. Paultre suggests cross-training to give muscles a break and reduce repetitive strain.

“You have to take time off [both physically and mentally],” he adds. “It’s not worth risking your health over sports.”

Written by Ana Veciana-Suárez, a regular contributor to the University of Miami Health System. She is an acclaimed author and journalist who has worked for The Miami Herald, The Miami News, and The Palm Beach Post.

Tags: Dr. Kristopher Paultre, Fitness regimen balance, Rest and recuperation, Signs of overexertion, Training intensity management