Exercise is often believed to have a dose-related response – the more you do, the greater the results. Undoubtedly, there is a certain amount of truth to this belief: often, the more you exercise, the more weight you will lose, or the more muscle you will gain, or the fitter you will become. However, as with most things, there are exceptions to the rule. Sometimes, more can be less – as can be the case when an individual is overreaching (non-functional) or overtraining.
Overreaching or Overtraining are diagnostic terms given to describe “a negative outcome in terms of performance, fatigue and other complaints, such as altered eating and sleeping patterns, concentration problems and changed mood states (including tension, depression, anger and vigour)”1. Diagnosis is based on a recovery:
- Functional Overreaching: If individual has recovered within a few days. This means we get fitter or stronger by challenging our bodies to adapt to the demands of the exercise or activities we perform.
- Non-Functional Overreaching: Recovery can take several weeks or months.
- Overtraining: This is the more severe version of these conditions, with recovery often taking longer – up to several months or even years.
Both non-functional overreaching and overtraining can have a negative impact on exercise outcomes, interfering with continued adherence to exercise, or long-term reductions in performance and participation in exercise and sports. Furthermore, the symptoms of fatigue, altered eating and sleeping patterns and disrupted mood, can potentially also result in weight gain.
Academically, these conditions are said to be the result of “periods of a disturbed stress-regeneration balance. This can be caused by a change in training regime or an important stressful psychosocial event in combination with insufficient recovery.”1 Simply put, overreaching and overtraining is caused by an unbalanced equation; too much stress (usually an increase in training load) and too little recovery.
So, what is the perfect balance between stress and recovery? How much high intensity exercise should you include in your weekly training plan to both optimise your results and avoid non-functional overreaching or overtraining? The answer is: it depends. This is because we all have different tolerances determined by many factors, including our exercise history, diet, recovery, age, the quality of our connective tissues etc – essentially, some people can tolerate a lot of high intensity exercise/high stress, while others can tolerate very little. However, to give you a useful guideline, according to Gottschall et all (2020) “for individuals who regularly exercise, 4%-9% total training time above 90% maximum HR is the ideal duration to maximise fitness and minimise symptoms related to overreaching”2. For those who exercise with less regularity, an even lesser amount of high intensity exercise (up to 100% low-to-moderate intensity exercise) is more appropriate.
1 Nederhof E, Zwerver J, Brink M, Meeusen R, Lemmink K (2007) Different Diagnostic Tools in Nonfunctional Overreaching. Int J Sports Med 2008:29: 590-597.
2Gottschall JS, Davis JJ, Hastings B, Porter HJ. (2020) Exercise Time and Intensity: How Much Is Too Much? Int J Sports Physiol Perform. 2020 Feb 28;15(6):808-815