Exercising too much, as per a 2022 study by Justin Carrard from the University of Basel, refers to a state of overtraining or overload in physical activity that exceeds the body’s ability to recover. It is characterized by a long-term decrease in performance and is often described as an overtraining syndrome (OTS).

The definitive signs of exercising too much include persistent fatigue, muscle soreness, reduced coordination, weight loss, mood changes, and frequent illness. However, these symptoms could also indicate underlying medical conditions.

Overtraining typically occurs in situations where there’s an imbalance between training and recovery. This might be when the person trains excessively without sufficient rest, or when overall stress levels are high and not adequately managed.

According to the study titled “Diagnosing Overtraining Syndrome: A Scoping Review,” functional overreaching, a short-term decrease in performance for up to 2 weeks, is considered necessary for improving athletic performance. However, if the reduced performance capacity lasts for more than 3 to 4 weeks without being followed by improved athletic performance, it’s likely overtraining.

What Is Overtraining?

Overtraining, as per the 2016 study by Jeffrey B. Kreher from Massachusetts General Hospital, refers to an excessive volume or intensity of exercise that leads to a decrease in specific athletic performance. It involves an athlete’s training load reaching their individual “tipping point”.

Overreaching, burnout, failure adaptation, under-recovery, training stress syndrome, unexplained underperformance syndrome, and muscle failure syndrome are some other terms used to describe similar conditions.

If not managed with appropriate rest and recovery, it can become a severe condition known as overtraining syndrome (OTS), where there are long-lasting performance decrements coupled with mood disturbance.

Overtraining and overreaching are two related concepts that refer to the consequences of excessive exercise without adequate rest and recovery. Overreaching is often considered a short-term condition that results from a temporary increase in training volume or intensity without adequate rest.

It’s usually resolved with a few days to a couple of weeks of reduced training or rest. Athletes often intentionally overreach in their training to push their limits, followed by a period of tapering or rest that allows the body to recover and adapt, potentially leading to performance improvements.

On the other hand, overtraining refers to a more serious and long-term condition that results from repeated cycles of overreaching without adequate recovery, leading to a decrease in performance that can’t be resolved by short-term rest.

How is Overtraining Measured?

Overtraining is challenging to measure due to the lack of valid diagnostic tools, according to a 2002 study by Axel Urhausen from the University of Saarland. However, certain physiological and psychological markers can indicate overtraining. These include:

Ergometric Tests: Overtrained athletes often have a decrease in sport-specific performance, an impaired anaerobic performance, and a reduced time-to-exhaustion in standardized high-intensity endurance exercise. The maximum heart rate and lactate levels may also decrease slightly.
Mood State and Subjective Complaints: A deterioration in mood state and complaints such as “heavy legs” and sleep disorders can be sensitive markers of overtraining, but these can be manipulated.
Blood Markers: Although not useful in diagnosing established overtraining, measurements at rest of certain blood markers like urea, uric acid, ammonia, creatine kinase activity, and specific hormones (including the ratio between free serum testosterone and cortisol) can reveal conditions that impair exercise performance long term.
Nocturnal Urinary Catecholamine Excretion: This, along with the decrease in the maximum exercise-induced rise in pituitary hormones (especially adrenocorticotropic hormone and growth hormone), provides relevant diagnostic information. However, hormone measurements may not always be practical.

Although these indicators help to measure overtraining, the study concludes that there has been little improvement in the tools available for diagnosis.

What Are The Causes Of Overtraining?

The causes of overtraining include the following factors.

Excessive Physical Training: Overtraining can result from an excessive amount of physical training without adequate recovery. The body needs time to rest and rebuild tissues after intense workouts; without this recovery time, the body may enter a state of overtraining.
Additional Stressors Outside of Training: The majority of athletes experiencing overtraining also reported experiencing additional stress outside of training. These non-training stressors could contribute to the onset of overtraining.
Inadequate Nutritional Intake: The athletes’ caloric and macronutrient intake is also a factor. If athletes are not getting enough nutrition to support their intense training regimes, this could potentially lead to overtraining.
Other Concurrent Cognitive Demands: Other cognitive demands, like mental stress or lack of sleep, can also contribute to overtraining. These factors can drain the body’s resources, leaving less energy for recovery after workouts.
Environmental Stressors: Factors in an athlete’s environment, like high-altitude training or extreme temperatures, can also contribute to overtraining.

Excessive physical training can lead to overtraining. According to a 2020 study by Clementine Grandou published in the International Journal of Sports Physiology and Performance, athletes who reported overtraining symptoms tended to be those training at high volumes.

For example, athletes were training an average of 10.5 hours per week, with a range of 1.5 to 30 hours per week. However, overtraining is not solely a result of high-volume training and can also occur with high-intensity training or a combination of high volume and intensity.

Work can be a major source of stress for individuals, and when combined with training maladaptation, it can lead to overtraining. If your job is particularly stressful or physically demanding, it can take a toll on your body and mind, making it harder to recover from exercise and increasing the risk of overtraining.

Additionally, work stress can impact your sleep and other essential recovery processes. It’s important to find ways to manage and reduce work-related stress to maintain a healthy balance between work and training.

Proper nutrition is critical for recovery and adaptation to training. If individuals are restricting their caloric intake or not getting a balanced diet, it can impair recovery and lead to overtraining symptoms. This is especially true if the dieting is severe or prolonged.

What Exercise and Sports Activities Cause Overtraining?

Overtraining is a condition that can arise from any physical activity or sport when the body is pushed beyond its ability to recover. While this can occur in any sport or exercise, certain activities are more prone to overtraining due to the intensity, volume, or frequency of their training routines. This is often seen in activities that involve heavy lifting or high-intensity workouts, such as powerlifting, bodybuilding, and weightlifting.

High-intensity interval training (HIIT) and CrossFit are also commonly associated with overtraining. These workouts are characterized by short, intense periods of exercise with minimal recovery time, which can quickly push the body beyond its recovery capacity if not properly managed.

Who is at The Most Risk of Overtraining?

According to a 2020 study from the University of Technology Sydney, athletes, especially those involved in endurance sports such as rowing, cross-country skiing, triathlon, speed skating, swimming, and cycling, are at the highest risk of overtraining.

This is largely due to the high-intensity training routines these athletes undergo, often without sufficient recovery time. As a result, they can develop overtraining syndrome, which is a state of prolonged fatigue and decreased athletic performance. This underscores the importance of balance between training and recovery periods to prevent overtraining.

What Are The Symptoms of Overtraining?

The symptoms of overtraining include the following signs.

Decreased performance
General feelings of fatigue
Musculoskeletal aches and pain
Decreased motivation
Lethargic
Perceived weakness
Increased perception of effort during training
Muscle soreness
Poor sleep quality
Poor concentration
Irritable
Excessive sweating
Muscle heaviness or stiffness
Lack of refreshment after rest
Recurrent injuries
A decline in exercise enthusiasm
Decline in motivation or self-confidence
Lack of enjoyment in hobbies
Signs of depression
Mood swings or unusual emotions
Sleep problems, such as insomnia
Concentration and performance issues
Changes to skin, hair, and nails, such as acne or hair loss
Increase in resting heart rate or blood pressure
Unplanned weight changes or disordered eating
Digestive issues, such as constipation or loss of appetite
Reproductive issues, such as decreased libido or menstrual changes
Frequent illnesses, such as colds or upper respiratory infections

This diagram lists some signs of potentially very serious overtraining.

Can Overtraining Cause Weight Gain?

Overtraining can cause weight gain, though the impact can vary based on the type of training and individual responses as per a 2015 study from the University of São Paulo, which investigated the effects of different running overtraining protocols.

In this study, researchers found that mice overtrained by downhill running had a decrease in body weight and food intake during the overtraining period. However, they exhibited increased body weight after a two-week recovery period. On the other hand, mice overtrained by uphill running increased their food intake during the overtraining period.

Can Overtraining Cause Fatigue?

Overtraining can cause fatigue.

Fatigue is a state of increased tiredness and reduced physical and/or mental performance, often resulting from exertion, illness, or stress. It is characterized by a lack of energy or motivation and can be physical, mental, or a combination of both.

Overtraining is characterized by prolonged fatigue and reduced athletic performance, despite increased training, as per E Randy Eichner from the University of Oklahoma Health Science Center.

This is largely due to a complex interplay of factors, including muscle damage, the body’s response to inflammation, improper nutrition, mood disturbances, and various effects of stress hormones.

Can Overtraining Cause Muscle Loss?

Overtraining can cause muscle loss.

According to research presented in the findings of the EROS (Endocrine and Metabolic Responses on Overtraining Syndrome) study, athletes affected by Overtraining Syndrome may experience a ‘hyporesponsive’ and ‘hypometabolic’ state characterized by decreased metabolic rate, impaired hormonal responses, decreased testosterone, a lower testosterone-to-estradiol ratio, and increased catecholamines.

These changes suggest an environment that is antianabolic and pro-catabolic, meaning it is unfavorable for muscle growth and favorable for a breakdown of body tissues, including muscle. This is believed to be a protective mechanism the body employs under chronic stress and can lead to paradoxical muscle loss.

The study suggests that altered metabolism markers, such as abnormal body fat gain and paradoxical muscle loss, might be early indicators of impending overtraining, even before biochemical results or performance decreases are noticed. Therefore, overtraining not only can cause muscle loss but can also lead to multiple metabolic, hormonal, and other systemic dysfunctions.

Can Overtraining Cause Insomnia?

Yes, overtraining can cause interruptions to sleep patterns, potentially leading to insomnia. A 2021 study by Eon H. Campbell from the University of the West Indies on elite adolescent sprinters found that those who did not properly adapt to their training regimen—and subsequently became overtrained—experienced lower sleep efficiency and quantity compared to those who adapted sufficiently to their training.

The research revealed that higher prior training volume was associated with lower sleep efficiency, which was in turn associated with poorer performance.

Fatigue, as a consequence of overtraining, was found to moderate the effect of sleep efficiency on performance, implying that impaired sleep due to greater training might lead to performance decrements via the pathway of increased fatigue.

Can Overtraining Cause Anxiety?

Overtraining can cause anxiety.

According to a 2021 study by Yi Chung from the National Taipei University of Nursing and Health Sciences involving an exhaustive eight-week treadmill exercise animal model, overtraining caused increased anxiety along with other deleterious effects on health and exercise capacity.

The exhaustive exercise group exhibited significantly lowered performance and imbalanced energy expenditure, a decreased body fat mass, and a slowed growth curve.

They also showed an increase in inflammatory cytokines along with elevation in specific immune cells, which was significantly more pronounced after successive exhaustive exercises. Furthermore, overtraining-induced stress resulted in increased anxiety status and a decrease in food intake.

The study, therefore, suggests that overtraining can contribute to the development of heightened anxiety, along with other physical and mental health impairments. This underscores the importance of balancing exercise and recovery to maintain health and performance.

What Are The Complications of Overtraining?

The complications of overtraining include neuroendocrine dysregulation, decreased sensitivity of adrenal glands, and decreased sensitivity to hormonal responses.

Neuroendocrine Dysregulation: Overtraining can lead to dysregulation in the neuroendocrine system which mainly involves the hypothalamic-pituitary-adrenal (HPA) axis and the autonomic nervous system (ANS). These are primary regulators of the body’s response to stress. When subjected to chronic, intense training without adequate recovery, these systems can become dysregulated, leading to hormonal imbalances that can impair the body’s normal functioning and responses to exercise.
Decreased Sensitivity of Adrenal Glands: The adrenal glands, part of the HPA axis, produce crucial hormones like cortisol that help the body respond to stress, including the physical stress of intense exercise. Overtraining can desensitize the adrenal glands, meaning they aren’t as responsive to signals from the brain to produce and release these hormones. As a result, the adrenal glands might not produce enough of these hormones when they’re needed, leading to decreased physical performance and increased fatigue.
Decreased Sensitivity to Hormonal Responses: The body’s hormonal responses play a pivotal role in how well the body recovers and adapts to exercise. Overtraining can reduce the body’s sensitivity to these hormonal responses. This can limit the body’s ability to repair muscle tissue, regulate metabolism, maintain a balanced mood, and perform other critical functions. Reduced sensitivity to hormones can make it more difficult for the body to handle stress, regenerate cells, or maintain optimal energy levels, ultimately affecting physical performance and overall health.

What Is The Treatment For Overtraining?

Since the symptoms can be varied and non-specific, there isn’t a single diagnostic test for overtraining. Therefore, prevention and rest is considered the most effective treatment. This generally involves balancing training and rest, monitoring mood and symptoms, reducing distress, and ensuring optimal nutrition, particularly total energy and carbohydrate intake.

How To Avoid Overtraining?

When asked how to avoid overtraining, Jeffrey B. Kreher, a pediatrician and professor from Harvard Medical School, explains that one way to prevent overtraining is by properly managing training loads. Gradually increasing training intensity and duration can help avoid excessive stress on the body.

It is also crucial to incorporate rest days into the workout schedule. These rest days allow the body to recover and adapt to the training stimulus.

Another important aspect to consider is nutrition. Consuming a well-balanced diet that provides adequate energy and nutrients is essential for optimal performance and recovery. Paying attention to hydration levels is also important, as dehydration can contribute to fatigue and muscle cramps.

Monitoring and listening to the body is crucial in preventing overtraining. Paying attention to signs of fatigue, decreased performance, and mood changes can help identify when rest is needed. Taking regular breaks and incorporating active recovery sessions into the training program can also help prevent overtraining.