This piece addresses an all too common scenario among trained athletes, the misconception that more is always better. It is possible to train too much, however it’s not always easy to tell if you are or not. Here, some of the research surrounding overtraining is discussed as well as signs, symptoms and ways of avoiding it.

Overtraining can be defined as an increase in training volume and/or training intensity that results in long term performance decrements (>2weeks), less severe forms of the syndrome can be termed overreaching and result in shorter recovery periods (<2weeks)¹. Functional overreaching can actually be a useful tool for use by your strength and conditioning coach to build tolerance to training for reduced stress in future high intensity training bouts⁴, it is when the overreaching occurs over too long a period and becomes non-functional and progresses to overtraining that the serious issues occur (see below table⁷).

Two forms of overtraining exist based on responses of the autonomic nervous system, these are called sympathetic and parasympathetic overtraining syndromes. Evidence suggests that sympathetic overtraining develops first in an attempt to maintain performance levels and physiological homeostasis, following this the parasympathetic form develops as the sympathetic system becomes exhausted². This is similar to the stress response first reported in 1936 by Selye³.

Responses to high relative intensity resistance training seen are an acute increase in circulating catecholomines i.e. epinephrine and norepinephrine (perhaps more commonly known as adrenaline and nor-adrenaline)⁴. In overtraining induced by long bouts of endurance training, the converse is true and a decrease in circulating catecholamines is seen⁵. Epinephrine and norepinephrine increase cardiac output, regulate blood vessels, increase glycogen breakdown and increases fatty acid release. Evidence of the initial sympathetic overtraining would include an increase in resting heart rate and blood pressure whereas the progression to the parasympathetic form the opposite would be seen as well as a reduced ability to utilize fat as a fuel. (This is a very brief overview of the physiological responses to high intensities of training without going into a detailed discussion of cellular and endocrine physiology).

So, what does this mean for the athlete, what are you going to notice as a result of these physiological responses to increases in training volume and/or intensity. If an unsustainably high training volume is allowed to continue unchecked, you may start to develop symptoms of overtraining syndrome, the most common of which are listed below⁶:

• Unexplained and persistent poor performance
• High levels of prolonged fatigue
• Prolonged recovery from typical training sessions
• Altered mood states including irritability and loss of drive
• Persistent feelings of muscle soreness and joint stiffness
• Elevated resting pulse
• Insomnia
• Loss of appetite and weight loss
• Overuse injury

Now that we are aware of some of the markers of overtraining, there must be a simple test to ensure that overtraining is not developing. The answer is yes and no. Research on overtraining is continuing to develop, but the practicalities behind studying it, namely ethical issues around inducing overtraining in athletes and/or finding athletes who already have the syndrome to question retrospectively, make it a difficult area to study. As a result the exact causes are still not fully understood. We know of some patterns such as peak power production during 1 RM lifts being adversely affected by overtraining⁵ as, it seems, is  agility⁸, but this is among strength athletes and the demands of 1RM testing often make it difficult to incorporate it on a regular basis. Given the large number of symptoms and the variation in response from athlete to athlete, there is perhaps never going to be a single solution to give a 100% guaranteed diagnosis, but it is possible to limit the chances.

The first course of action is a training diary to record all your training in, this allows you and your strength and conditioning coach to monitor your training volumes as accurately as possible. Next, you need to make a, preferably daily, record of certain markers (resting heart rate, bodymass) to track development of any symptoms. We use a short questionnaire and track your responses to ensure any early development of symptoms is noticed and your training program altered accordingly, hence the need to carefully track training volume. Finally, regular measures of performance will ensure any drops are picked up early and the suitable recovery is prescribed. By following these courses of action, any lengthy spells out to recover can be avoided.

1. Budgett ,R ,. Newsholme, E., Lehmann, M., Sharp, C., Jones, D., Peto, T., Collins, D., Nerurkar, R. & White, P. (2000). Redefining the overtraining syndrome as the unexplained underperformance syndrome. British Journal of Sports Medicine 34 pp.67– 68.
2. Barron, G., Noakes, T., Levy, W., Smidt, C. & Millar, R. (1985). Hypothalamic dysfunction in overtrained athletes. Journal of Clinical Endocrinology & Metabolism, 60 pp. 803– 806.
3. Selye, H. (1936).  A syndrome produced by diverse nocuous agents. Nature 138 pp. 32.
4. Fry, A.C., Kraemer, W.J., van Borselen, F., Lynch, J.M., Triplett, N.T., Koziris, L.P., and Fleck, S.J. (1994). Catecholamine responses to short-term high- intensity resistance exercise overtraining. Journal of Applied Physiology, 77 pp. 941–946.
5. Fry, A.C., Schilling, B.K., Weiss, L.W. & Chiu, L.Z.F. (2006). ?-Adrenergic receptor downregulation and performance decrements during high-intensity resistance exercise overtraining. Journal of Applied Physiology, 101 pp. 1664-1672.
6. McArdle, W.D., Katch, F.I. & Katch, V.L. (2001). Exercise Physiology: Energy, nutrition and human performance (5^th ed). Training for anaerobic and aerobic power 458-499.  Philadelphia: Lippincott, Williams & Wilkins.
7. Meeusen, R., Duclos, M., Gleeson, M., Rietjens, G., Steinacker, J & Urhausen, A. (2006).  Prevention, diagnosis and treatment of the overtraining syndrome.  European Journal of Sport Science, 6(1) pp: 1-14.
8. Moore, C.A. & Fry, A.C. (2007).  Non-functional overreaching during off-season training for skill position players in collegiate American football.  Journal of Strength and Conditioning Research, 21(3) pp. 793-800.