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Posted: September 16, 2005
Science of Sport: Overtraining Syndrome
Once summer begins to wind down, two different types of athlete appear. The first has been training outdoors all summer. They are now ready to make a final push in their training for the large races that take place in the fall. The second has slacked off their normal routine while away from the gym and up at the cottage. This athlete is determined to regain lost endurance and strength as quickly as possible. Both scenarios potentially lead to Overtraining Syndrome by stressing the body physically and emotionally.
Overtraining Syndrome is recognized as over-stimulation of the stress response in athletes and leads to reduced performance, exhaustion, suppression of the immune system and poor motivation. It comprises physical, behavioural and emotional components persisting for weeks to months recognized initially as “burn out.”
Features of Overtraining Syndrome:
1. Plateaued or reduced performance 2. Fatigue 3. Altered mood and/or irritability 4. Altered/poor sleep pattern 5. Poor motivation and reduced competitiveness 6. Reduced appetite and associated weight loss 7. Persistent muscle soreness 8. Increased injury rate, poor healing and recovery 9. Increased incidence of viral illness
Training and performance
“No pain, no gain.” To improve performance you have to work hard. It is well known, however that it is the rest periods between periods of exercise that make you stronger. The changes in cardiovascular and muscular systems including improved efficiency, increased energy stores and higher enzyme levels occur during the periods of rest and recovery following vigorous exercise. Overtraining syndrome is not a result of training too hard, it is a result of training with inadequate rest and recovery periods. The athlete will eventually reach the point at which sufficient damage and deterioration have been done that even increased periods of rest are insufficient to provide adequate recovery of function.
The incidence of OTS is more common than generally appreciated. Rates of up to fifty percent for elite athletes in individual sports have been identified in some studies. The incidence in individual sports is significantly higher than team sports and less demanding sports. In addition, it appears that other stressors including emotional and psychosocial stressors contribute to the problem in addition to pure over training.
Overall, it appears that athletes are inclined to do too much training, convinced that this is necessary in order to perform at a high level. They “train hard so they can train even harder.” High-level exercise induces the cellular and metabolic changes that are corrected during periods of rest. Vigorous exercise leads to over compensation during the recovery phase often referred to as “super compensation.” At this point the body’s cellular and metabolic systems have been reset at a slightly higher and more efficient point. Once this is achieved, it is considered optimum time for the next period of training. Unfortunately, identification of this point in specific individuals has proved elusive. There appears to be an ideal period during which increased training volume improves performance. Attaining the peak is essential for success, as even a small percentage decrease on either side in international competition will likely mean the difference between wining and losing.
Types of overtraining
Over Reaching – Often considered one of the earlier stages of over training, over reaching is likely a result of insufficient metabolic recovery associated with low levels of glucose stores (glycogen) and inadequate generation of energy providing ATP. Over reaching is associated with muscle fatigue and is usually encountered after a short period of hard training. It is generally rapidly reversed by appropriate rest and nutrition.
Over Training Syndrome – Over training syndrome is also known as training staleness or burnout. There are a number of theories as to its cause but little agreement on specific diagnostic findings. To complicate matters it is possible to have many of the features of over training syndrome but a completely normal physical examination and biochemical tests.
Diagnosis and Theories of overtraining syndrome
The early stages of OTS are often considered “over reaching” and increased resting plasma concentrations of noradrenalin have been identified. This would be in keeping with the proposed over activity of the sympathetic nervous system at this stage of the process. In established OTS, decreased night-time urinary excretion of adrenalin and noradrenalin has been identified and may represent the late stage parasympathetic phase of OTS with collapse of the sympathetic system. Absolute serum cortisol levels do not show consistent irregularity but, as we have noted previously, this measure is an unreliable indicator of the state of the stress response. What is more important is the reduced responsiveness of the adrenal gland to stimulation by ACTH and the impaired feedback on the hypothalamus and pituitary seen in these individuals.
Attempts at subjective measurement of mood state may be useful in identifying psychological and motivational disturbances associated with OTS. However, it would appear that deterioration in mood precedes deterioration in performance by a considerable period of time. In addition, high-level athletes are often able to mask the psychological component of their condition for fear of being dropped from the team.
Impairment of the immune system is well recognized in OTS and one of the diagnostic features is an increased incidence of viral infection. Certainly, the high cortisol resulting from vigorous exercise causes a decrease in circulating lymphocytes and impaired release of inflammatory cytokines and prostaglandin’s. Certainly a reduction in interleukin production is known to impair the cell-mediated immune response. Increased cortisol in association with exercise causes a reduction in glutamine levels, which are essential nutrient components of the immune mechanism. Further studies have demonstrated a reduction in natural killer (NK) cell population and activity following vigorous exercise. Under normal conditions recovery following exercise is rapid and the changes in the immune system temporary. However, in OTS there appears to be a cumulative effect with failure of the immune mechanism to return to normal. This is thought to result in decreased resilience in particular to viral infections.
Currently, the most reliable test for OTS is a reduction in sports specific performance.
Theories of Overtraining Syndrome
1. Dysfunction of the cortisol response – An abnormal sensitivity and feedback within the stress response (hypothalamic-pituitary-adrenal axis).
2. Autonomic imbalance –Two types of autonomic imbalance as related to OTS have been identified. One involves sympathetic hyperactivity; the parasympathetic form usually represents a collapse following a prolonged period in the sympathetic phase. This collapse is associated with reduced response to exercise. In effect, “You step on the gas and nothing happens.”
3. Cytokine Hypothesis –Cytokines (inflammatory chemicals) released as a result of vigorous training, induce changes in mental status, metabolism, immune function and muscle recovery.
The best treatment is prevention with adequate rest days in your program, proper monitoring of heart rate, hormone levels and symptoms. Varying intensity as well as duration is essential. If you are unsure how to identify these factors, invest in a personal trainer or coach who can safely maximize your work-outs and prevent OTS.
The treatment for established OTS is essentially rest. The longer the period of overtraining, the longer the rest period required. 3 to 4 weeks of overtraining usually requires 3 to 5 days or complete rest. Following this, training can be commenced on alternate days. Extreme overtraining may require many weeks of rest although to avoid “withdrawal” the athlete may train in other sports.
A sound nutritional program catered to your particular sport (strength-training or endurance) is essential. This should involve a range of 1 to 1.6 grams of protein per kilogram of body weight depending on your sport and level of training combined with adequate. The diet should be supplemented with anti-oxidants, such as vitamin A, C, E, selenium and CoQ10 to minimize inflammatory free radical damage. Calcium-magnesium, cysteine and glutamine are also crucial for repair and maintenance of the body. Herbs that support and strengthen the adrenals such as magnolia flower, rhodiola or astragalus help to prevent and treat abnormal stress hormone response during intense training. Training should include cross training, massage, meditation, deep breathing or some form of relaxation to off set the vigorous exercise.
For more information see “The Complete Doctor’s Stress Solution” by Penny Kendall-Reed and Stephen Reed.
This article is an excerpt from "The Complete Doctor's Stress Solution" by Penny Kendall-Reed ND and Stephen Reed MD (Published by Robert Rose Canada 2004)
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