All About Overtraining

Blog by: Tatum Boyd, 2022 Undergraduate Summer Research Student

Athletes are often told to keep going, to push themselves beyond their limits and constantly strive for improvement. However, regularly overdoing it on the field, in the gym, or wherever you train, without proper fuel, rest, and recovery can lead to overreaching or overtraining. We want to provide athletes and coaches with the necessary information to better understand how to train safely and effectively to optimize health and performance, while also recognizing and respecting the athletes’ limits.

Let’s Begin by Understanding the Stages of Overtraining

Functional Overreaching (FOR)

  • When training loads cause short-term performance decrements, followed by supercompensation improvements
  • Generally occurs over a short-term period of time (days to weeks) when matched with adequate recovery

Non Functional Overreaching (NFOR) 

  • Unplanned fatigue over time (weeks to months of performance decrements)
  • Occurs when athletes are overreaching for weeks to months

Overtraining Syndrome (OTS) 

  • Chronic overreaching that results in more long-term decreases in performance and impaired ability to train
  • May take months for full recovery


Although there is a previous OTS framework with distinct time frames and levels of energy availability for each of the three stages, recent work has established that there is much more variability between individuals and overlap between stages (Stellingwerff, et al., 2021). Therefore, the prevention of OTS should be primarily based on awareness and monitoring, as opposed to following the specific framework that often leads to misdiagnosis. Early recognition, awareness, and intervention when symptoms are still minor, are crucial to properly treating OTS.

So what are the symptoms?

There is wide variability in the symptoms of OTS, involving several health and performance factors. Responses to overtraining may vary between individuals, so it is difficult to create a distinct list of symptoms applicable to athletes of all ages and abilities. 

To the right are some of the most common symptoms demonstrated by athletes experiencing FOR/NFOR/OTS (Friedlander, 2021):

Similarities Between Overtraining and RED-S

Note that many of these symptoms may also be demonstrated in athletes experiencing RED-S. There is no singular diagnosis method for either OTS (or FOR/NFOR) or RED-S, as both syndromes consist of a complex overlap of symptoms. RED-S and OTS are diagnoses of exclusion with a number of considerations where decreases in performance are usually paired with variable psychological/emotional, physiological, immunological, and neuroendocrine effects (Stellingwerff, et al., 2021). Low energy availability (or RED-S) must be ruled out prior to making an NFOR/OTS diagnosis. RED-s is commonly misdiagnosed as OTS, so it is important to make the distinction between the two early on. If you are concerned about overtraining or experiencing some of these symptoms, you should speak with a sports medicine doctor to determine the proper next steps for you! 

Prevention of Overtraining

As overtraining symptoms and progression varies between individuals, so might prevention of overtraining. There a few key elements to monitor in helping prevent progression of OTS in most athletes (Kellmann, 2010).

  • Careful observation of training load + rest and recovery
  • Ensure proper fueling
  • Observation of mood and stress
  • Ensure proper rest between sets within a workout and between individual training sessions
    • Specific amounts of rest and recovery necessary will vary according to individual factors including the type of training, age of the athlete, level of training, length of training session, etc.

  • Athletes must properly fuel to match energy expenditure during training.
    • It is important to know your fueling needs: eat when you’re hungry and recognize that you may also need to fuel when you’re not.
    • Avoiding eating or skipping meals are common mistakes that can lead to underfueling.
    • As training intensity/volume increases, fueling needs also increase!
    • Carbohydrates are especially important in meeting proper energy needs for athletes and the body’s carbohydrate stores must be refilled following training sessions.
  • Questionnaires/surveys or self reflection can be used to help interrupt the progression of OTS, as well as to determine the proper training load based on the athlete’s mood and stress level.
    • Mood and stress levels can have a large impact on recovery states and perceived level of exertion with training, which are key to monitor in preventing any progression of OTS.


Although more research is needed for general OTS treatment, it is best to take an individualized approach. Rest, proper fueling, and extremely light training seem to be the main therapeutic agents affecting recovery. With this being said, emphasis should be on prevention of OTS (via appropriate periodization of training with particular focus and execution of appropriate recovery time within the training program) and on early diagnosis of NFOR and OTS, which has the ability to shorten the recovery time. 

Although emphasis should be on prevention, there are still helpful OTS recovery recommendations that can aid the recovery process (Meeusen, et al., 2013).


Despite the prevalence of OTS, many athletes, coaches, and parents remain unaware of OTS and its effects. Spreading awareness and educating athletes and coaches of all ages and levels of sport is important to ensuring any possible prevention of OTS (Kellmann, 2010). Prevention efforts are the key to success in ensuring safe, proper training with adequate rest, recovery, and fueling!


  1. Friedlander, A. (personal communication, 2021, November 30). The Power of the Mind and Limits. Exercise Physiology. 
  2. Kellmann, M. (2010). Preventing overtraining in athletes in high-intensity sports and stress/recovery monitoring: Preventing overtraining. Scandinavian Journal of Medicine & Science in Sports, 20, 95–102.
  3. Meeusen, R., Duclos, M., Foster, C., Fry, A., Gleeson, M., Nieman, D., Raglin, J., Rietjens, G., Steinacker, J., Urhausen, A., European College of Sport Science, & American College of Sports Medicine (2013). Prevention, diagnosis, and treatment of the overtraining syndrome: joint consensus statement of the European College of Sport Science and the American College of Sports Medicine. Medicine and science in sports and exercise, 45(1), 186–205.
  4. Stellingwerff, T., Heikura, I. A., Meeusen, R., Bermon, S., Seiler, S., Mountjoy, M. L., & Burke, L. M. (2021). Overtraining Syndrome (OTS) and Relative Energy Deficiency in Sport (RED-S): Shared Pathways, Symptoms and Complexities. Sports Medicine, 51(11), 2251–2280.

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