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The perils of overtraining

Overtraining could be detrimental to both your health and performance, are you at risk?

With exercise and training, it’s true that you get out exactly what you put in. The problem is that if you put too much in, without enough time for recovery, it could be damaging to your health and performance.

There is a fine line between training and overtraining. So, how much is too much? What can overtraining lead to? And how can you find your balance? We investigate…

What is overtraining?

Overtraining refers to a high training load with insufficient time for recovery between sessions. It can also be called ‘under-recovering’ as the lack of recovery is a key cause.

Overtraining is not specific to any exercise type; it can occur in endurance training, strength training, resistance training and many more.

What can overtraining lead to?

Overtraining can affect your whole body and cause hormonal changes and changes to your mental health and immune system. Changes you experience may include:

  • Loss of beneficial adaptions to training. In other words, your hard work was not worth it. You will not get any fitter or stronger or gain the performance benefits which you expect.
  • Reductions in performance. This is also known as underperformance. Whether it is weightlifting, sprinting, or endurance events, you will not be able to perform to your full capacity. This effect can last for over 2 months.
  • Hormonal changes. Overtraining can reduce crucial hormones such as testosterone, which can hamper abilities to build muscle and strength. In addition, high levels of cortisol may impair the capacity for muscle synthesis and recovery [2].
  • Physical symptoms, such as frequent infections, chronic fatigue, weight loss and muscle weakness.
  • Psychological symptoms, such as depression, loss of motivation, irritability.

How do you know whether you’re overtraining?

It is essential to distinguish between overreaching and overtraining.

Overreaching refers to a single, short-term decrease in performance, but this will be followed by a full recovery or improvement in a few days. In-fact, overreaching may sometimes be beneficial because, despite the short-term decrease in performance, your body will adapt to become fitter and stronger.

Overtraining, on the other hand, refers to a long-term decline in performance. It can take weeks or months to recover from and is accompanied by long-term changes in biochemical, psychological, and physiological changes.

The reason why some athletes become over-trained, when others do not, is not clear. Although it appears that those who are highly motivated and regularly attempt to endure heavy-training loads are most at risk of overtraining. Also, taking in little energy, in the form of calories from your food, may contribute to your overtraining risk.

To avoid overtraining, you must give your body enough rest periods, along with optimal nutrition, to allow it to repair. Though sometimes it can often be challenging to know whether you are doing the right thing. You can often feel as though you have recovered, even though your body is telling a different story on the inside.

Blood testing is a powerful way to uncover what is happening inside your body. Our Ultimate Performance Blood Test is a valuable way to assess levels of important biomarkers (biological markers). This includes hormones such as testosterone and cortisol, along with high-sensitivity CRP (CRP-HS), a biomarker of inflammation, and creatine kinase, a biomarker of muscle damage.

Following a workout, these biomarkers usually increase for the short-term but should settle over 2-3 days. If these biomarkers remain elevated, this could be a sign you are overdoing it.

How to avoid overtraining and discover your balance.

  • Rest and recoup. Make rest days, and adequate sleep (for at least 6 to 8 hours!), as much of a priority as your training. It is only during rest periods that your body can repair your muscles and can grow to be stronger. As soon as you start to prioritise these, you will gain the benefits.
  • Acceptance. This will be beneficial for both your body and mind. Allow yourself to accept as soon as you have done enough, and no more. It can be useful to keep a training diary and plan your workouts ahead of time, including your rest days. If you have not done anything more but stuck to your plan, this is enough. You can relish in the feeling of accomplishment.
  • Adequate nutrition. To recover in the best way possible, you need to supply your body with the building blocks it needs. These come in the form of nutrients. The most important nutrients to replenish after a heavy work out are the macronutrients carbohydrate and protein. For example, on a training day, as a general guide (depending on workload and your personal body), you will need 7-12g of carbohydrate per body weight (kg). For a 75 kg man, this is equivalent to 750 g carbohydrate. This may be tricky to achieve in one meal, so it is advantageous to split this across a day post-training.
  • Blood testing. Everyone is different, so therefore blood testing is a powerful way to uncover whether you are providing your body with enough time to recover in between training periods and are therefore ready to restart. There is no single reliable biomarker to indicate overtraining. Professionals agree that a comprehensive mixture of biomarkers, including cortisol, testosterone, creatine kinase, and high sensitivity CRP (CRP-HS), along with physical and psychological symptoms, can indicate overtraining.

Our Ultimate Performance Blood Test is a valuable way to measure your biomarkers, and uncover whether they’re remaining elevated, which can indicate overtraining. Repeated testing over time can also help you to identify the optimal time to restart your training.


[1]Maughan, R.J., Maughan, R.J. and Gleeson, M., 2010.The biochemical basis of sports performance. Oxford University Press.

[2]Lee, E.C., Fragala, M.S., Kavouras, S.A., Queen, R.M., Pryor, J.L. and Casa, D.J., 2017. Biomarkers in sports and exercise: tracking health, performance, and recovery in athletes. Journal of strength and conditioning research, 31(10), p.2920.