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Over Training Syndrome (OTS)

Our Perspective on Human Performance

Over Training Syndrome (OTS)

Over Training Syndrome (OTS)

The end of the competitive cycling season (north of the equator) is nearly upon us, with the exception of a few nasty hill climbs and some World Champs excitement, hopefully. At this time of year you are probably assessing how well your events have worked out or not, whether you’ve noticeably improved in performance (hopefully relying on objective and robust testing) compared to last year.

Congratulations if you’ve got your training balance right and you have been smashing the hills feeling fresh and recovering well after each session. You should be looking forward to a short break soon, to totally rest the body (and mind) from the months of battering it has received. This will let it recover from the inflammation due to hard training rides or races, and give the muscles a chance to repair themselves properly and regain some normality. Typically during this period, as training volume decreases drastically, super-compensation from the totality of training tends to come in to play. This may be taken advantage of for those last couple of events and gain some last minute personal bests. Following that, de-training usually takes hold, and performance tends to ebb away before winter programmes should be re-started.

If things have not gone so well then you may not have been including this sort of rest more ‘acutely’ during your training programme, especially if your sessions are intensive, infrequent and are squeezed between a stressful life routine which can be prohibitive to full recovery. More often than not, healthy conclusions to training adaptations may take much longer than thought, to result in a stronger physiological state. That is, when compared to someone who has no-stress, and can sit around all-day after their training ride thinking about what’s for dinner….if you know ‘who’ I mean. Therefore, packing in further training sessions is all too common, as poor performance is often mis-interpreted with insufficient training volume/ intensity as opposed to problems in recovery.

When it goes wrong?

In the short term we can see how a few sessions can have a significant effect on fatigue/ stress. These are usually fully recoverable from once training is stopped. This is the natural mechanism of training adaptation and commonly termed ‘functional over-reaching’ (FOR). Although, longer term, such as at the end of the summer, continuation of random or poorly timed intensive sessions can tip an individual into the over-training arena, which may perpetually result in further under performance, psychological burn-out and mis-perception of lack of training. This sub-healthy athletic state has more recently been termed NFOR- (Non Functional Over-Reaching) in which there is inadequate recovery, a prolonged period of over-load and where performance stagnates. This can happen any time of the year, but most commonly late in the competitive season.

It can often take months or years of entering into this vicious cycle which can then manifest itself as an Over-Training syndrome (OTS). A direct cause cannot be pin-pointed. Rather a multiple of potential contributing factors over a continuum of time (or possibly in discrete stages in functional to non-functional over-reaching), beyond that of quantifiable training. Risk factors may include some of the following:

  • Work and home life stress.
  • Underlying medical issues, (depression/illness)
  • Extreme or unusual training stress;
  • Major changes at home;
  • Increased work responsibilities;
  • Inadequate or improper nutrition;
  • Excessive expectation compared with realistic potential;
  • Sudden jump in intensity, duration or both;
  • Lack of adequate recovery;
  • Monotonous training routine;
  • Too much high-intensity effort.


Testing and Diagnosing OTS

OTS is a multi-dimensional disorder associated with a decrease in performance and prolonged changes in immune function (low white blood cell count), hormonal markers such as ACTH/Cortisol and psychological symptoms. Characteristics of the physiological state can include:

  • Lack of sleep/ poor sleep.
  • Feeling of injury, not just tiredness.
  • Muscle cramps.
  • Dropped by riders which aren’t usually better.
  • Doesn’t have any power/ strength.
  • NFOR several weeks rest then only a slow TSS build sustainable.
  • Confirmed negative state of training.
  • At the physiological level there is often muscle cell destruction/ inflammation / general fatigue / sympathetic nervous system disturbance including change in resting heart rate / disturbance of pituitary hormones – serotonin and chronic stress.
  • POMS- Profile of Mood State – a standardised psychological questionnaire Measures.
  • Vigor +/-ve / Fatigue / Anger / Tension / Depression.


Because OTS is a vague collection of multiple factors, no single stand-alone assessment exists to aid its diagnosis.

Tools for diagnosing OTS at rest a) Heart Rate (Urhausen & Kindermann, 2002). b) Mood State and Subjective Complaints, for example, the POMS questionnaire (The POMS questionnaire assesses tension, depression, anger, vigour, fatigue and confusion (McNair, Lorr & Droppelman, 1971). The physical demands of overtraining are not the only elements in the development of OTS (Armstrong & Van Heest, 2002). A complex set of psychological factors are important in the development of OTS, including excessive expectations from a coach and family, competitive stress, personality structure, social environment, relations with family and friends, monotony in training, personal and emotional problems, and school or work related demands (Armstrong & Van Heest, 2002)). c) Blood tests including enzyme activities and metabolic markers, for example, Creatinine kinase (CK), urea, uric acid and ammonia (Rietjens, Kuipers, Adam, Saris, van Breda, van Hamont & Keizer, 2005) d) Hormone testing, for example, catecholamines and testosterone, including the cortisol ratio (Brukner & Khan, 2006) e) Immunological Parameters such as Glutamine (Urhausen & Kindermann, 2002)

A more in-depth lab-based assessment may look at a combination of performance and biochemical marks over a range of power/ heart rate values. Where a duplicate maximal incremental ramp test may be conducted to look at cortisol, ACTH, and a spike in stress markers NFOR/OTS. A low maximal lactate vs max HR may be demonstrated in baseline and successive tests. However it is difficult to appraise the severity of over-training going forward (prospectively) as performance will naturally decrease with prolonged rest, because of the normal process of deconditioning. Hence why a retrospective analysis works best where current performance can be compared to historical assessments to track changes in power/ heart rate variability and recovery over time. That way a trend may be obvious if the individual is under performing during periods of high training volume, then more adequate recovery can be included as necessary. See the paragraph on preventing OTS below.

In all, if all other possibilities to explain what the athlete is experiencing can be eliminated, then OTS must be the most likely!


Risks of further Over-Training?

If OTS is not resolved, or is prolonged indefinitely it can lead to more severe health problems. The hypothalamus-pituitary axis (exocrine glands termed-HPA) in the brain is responsible for hormone production related to endurance exercise, adrenaline, cortisol and growth hormone (GH). The HPA can become dysfunctional long term as excessive exercise causes an increased secretion of cortisol, a stress hormone responsible for metabolic regulation and inflammation which in turn is responsible for immunological / biochemical abnormalities and suppressed psychological processing. In OTS, there is a decreased maximum exercise related increase in GH and ACTH.

Typical risk factors of HPA-dysfunction include:

Personality/ lifestyle/ occupation factors; Perfectionism; Trauma/ Perceived stress; Shift Work Teaching/ Healthcare/ Professional/ Middle management; Over-Training; Under-employed; High consumption of refined flour/ sugar; Hypothyroidism.

Chronic training can stimulate an over-production of CRH/ ACTH release, controlling normal cortisol in early stages of over-training. In later stages there is inhibited HPA activity and cortisol secretion is dysregulated. In turn, a decreased adrenal responsiveness to ACTH leads to an adrenal insufficiency (AI). This state may still be resolved if rehabilitation and cessation of training occurs for a prolonged period.

However if this state continues unchecked or is ignored then Adrenal Depletion (AD) can ensue, where adrenaline can be barely produced. This can cause a physically stressful autoimmune event known as ‘Addisonian crisis’ from the condition known as Addisons disease where there is total adrenaline shutdown. A sudden penetrative lower back pain in the abdomen or legs, severe vomiting, diarrhoea followed by dehydration, low blood pressure and loss of consciousness which may become fatal. Addisons type OTS can manifest itself where the adrenal glands are no longer able to maintain proper hormone levels and athletic performance is severely compromised, which is often experienced as ‘burn-out’ or ‘staleness’. Training alone is a rare cause.

Symptoms: Fatigue, poor sleep (non-restorative), Ill-defined malaise, loss of ambition, increased fear/ apprehension, scattered thinking, decreased concentration/ thinking, short fuse, hypocalcaemia, slow recovery to illness, allergies autoimmune, aches arthritis, excessive consumption of caffeine/ stimulants, feel better towards evening, decreased sex-drive.

AI/ AD- correction can take months:

  • Severe (years).
  • Replacement therapy.
  • Body ceases to produce essential hormones naturally.
  • AD requires lifetime replacement therapy of corticosteroids.
  • Characterised by many CFS-Like symptoms, persistent fatigue/ debilitating.


Preventing OTS

Predicting the effect of a particular workload can be difficult because of the relative nature of periodised training  shown by the performance management chart (PMC). This generally means a wide fluctuation in workload throughout the year, making it hard to establish a baseline for performance. Over-training is fundamentally an imbalance of too much stress with insufficient recovery or regeneration. Therefore rest and removal of training stimulus and other stress is key to the process of recovery.

As performance will naturally decrease with prolonged rest, because of the normal process of deconditioning, avoiding the need for rehabilitation is a preferred strategy. Common sense prevention strategies should include:

  • Challenging and realistic goals- not unattainable.
  • Support from family and friends.
  • Positive atmosphere- regular contact with coach.
  • Maintain training logs – Quantify/ Qualify data.
  • Avoid monotonous training of the same workloads, routes and pattern of work-outs.
  • Individualised training programs better than assigning general templates.
  • Severe reduction or complete termination of training.
  • Premature return to training will negate much of the gains made through the recovery process
  • Consistent and unified message to the athlete.
  • Self-awareness and proper recovery habits
  • Complete rest – mild training.
  • Correct balance of non-training related matters – contributed to NFOR/ OTS.


This may also mean following a well-considered and structured periodisation plan with adequate overload/ recovery to maintain physiological and psychological regeneration. Tracking the overload / recovery cycle is now more easily done with a short power/ heart rate based interval session for objective assessment. The reliable and predictive Lambert Sub-Maximal Cycle Test (LSMCT) can be conveniently incorporated into any programme without disrupting training, to objectively track changes in heart rate variability, recovery and related fatigue.

Feel free to learn more about the cause of OTS, presentation (symptoms), biochemical mechanism, prevention and treatment by subscribing to our complimentary info PDF here.

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