There are numerous health benefits from being more active and less sedentary. However, people often believe that more is better in regards to training, while the research indicates otherwise. So when does the level of physical activity become unhealthy? How do you get the beneficial psychological and physical benefits of physical activity without forming dysfunctional and excessive exercise behaviours?
There are three terms to define and consider:
Overtraining occurs when the body cannot keep up with the physiological demand of the exercise, having negative consequences on many physiological systems. Overtraining can often lead to exercise dependence.(1)
Exercise dependence occurs when a person becomes addicted to exercise, training multiple times a day and can experience withdrawal.(1)
Excessive Exercise has diagnostic criteria in the DSM IV (The Diagnostic and Statistical Manual of Mental Disorders - 4th Ed) These are exercises that:
- Significantly interferes with important activities
- Occurs at inappropriate times or in inappropriate settings
- Continues despite injury or other medical complications
Jonathon Mond et al. suggests that if a person experiences intense guilt when planned exercise cannot be undertaken and when exercise occurs to solely influence weight or shape.(2)
So exercise is determined to be excessive if intense guilt is experienced when it is postponed and when it is undertaken solely to influence weight or shape.
If there are inadequate periods of rest and recovery, there will be a vulnerability to the consequences of overtraining. This can affect athletes and any person who has an abnormally high level of a physical activity.
Physiological Problems with overtraining may include:
Increase physical activity causes a rise in Catecholamine levels in the blood and reduces the process of converting blood sugars to energy. This also affects the subsequent metabolism of these hormones. (3,4). As a result, fatigue and lethargy are experienced.
A decrease in testosterone (responsible for sex characteristics and anabolic growth processes) which leads to an increase in cortisol concentration. The increase in cortisol levels affects the regulation of liver and skeletal muscle function as well as the levels of adipose tissue. (5) The disturbed ratio of these two hormones has also been related to an increased catabolic state accompanied with stress fractures and/or joint injury. (6) This evidence highlights the need for rest particularly for people suffering muscle dysmorphia. Those individuals have body misperception where they do not believe they are big enough and (2) of the diagnostic criteria are excessive exercise and a fear of injury that would disrupt their training regime.
Dysfunction of the hypothalamus and the pituitary hormones including reproductive and stress-related hormones is also observed with overtraining, resulting in amenorrhoea in females and reduced sperm count in males. This disturbance can also affect emotional health.
Health is not merely the absence of disease, but a balance of physical, mental and social wellness. Overtraining actually lowers our immune response and lowers our resistance to illness. (Hackney et al, 1990) This is believed to be the result of decreased glutamine concentrations in the blood as a result of overtraining. (7)
Neuromuscular and Skeletal
The notion of ‘no pain no gain’ is a myth as supported by studies that show severe muscular soreness does not result in increased performance. (8) The soreness is a result of increased blood lactate levels and increased cortisol as mentioned previously. Soft tissue damage and inflammation of tendons and joints further contribute to injury.
Effects to Cardiovascular System
It has also been found that due to the hormonal disruption with overtraining that haemoglobin concentrations in the blood are reduced, affecting the bodies capacity to deliver oxygen to working muscles. This results in a reduction of VO2 (oxygen carrying capacity in the blood) and is also associated with increased blood lactate levels. (4)
Excessive exercise is often associated with muscle dysmorphia.
This may often involve the use of substances to influence muscle mass. The enlarging of the heart due to the prolonged use of these substances causes the function of the heart to decrease in efficiency. Coupled with haemoglobin reductions, the lack of oxygen can lead to sleep apnoea and eventually heart attack and potential death.
Psychological Effects of Overtraining
Overtraining has also been linked with psychological problems and these factors can be identifying markers of overtraining. Research has found that athletes have reported feelings of fatigue, depression, apathy, impaired concentration and sleep disorders following 10 days of intensive physical activity. (9)
The psychological signs and symptoms can include:
- Increased anxiety
- Instability of emotions
- Becoming more easily distracted
- Poor concentration
- Decreased self-esteem
- Increased feelings of Depression
- General apathy
These self-reported signs and symptoms are found to accurately represent indicators of overtraining.(1)
Furthermore, when a person experiences these symptoms, in conjunction with increased pressure to perform and other life stressors, decreased performance and withdrawal from training can result. This has been termed “Training Stress Syndrome” (10)
REST FOR GOALS SAKE!!
Since overtraining can lead to exercise dependence and further to excessive exercise, the risk of these physiological and psychological consequences increases. The need to rest for health’s sake is ignored and individuals who become exercise dependent or exercise excessively have no desire to change their high levels of exercise intensity and/or frequency.
The main difference between the three states is the level of compulsion to exercise and the anxiety it causes.
Excessive exercise is often also accompanied by strict rules and behaviours around food. Together, these are precursors of diagnosable eating disorders.
Crossing the line from healthy to unhealthy levels of exercise can be subtle but the consequences are extremely harmful to our physical, mental and social health. Allocating days of rest is essential not only for our health but for sports performance as well.
Not to mention, rest actually assists in achieving the goals that are set as opposed to impeding them.
- Examine your motivation.
- Listen to your body.
- Recognise fatigue and stress as a need to rest.
And finally, enjoy the rest, knowing that you are doing your mind and body a favour and working towards your goals in a healthier, more productive and effective way.
1. Adams, Jeremy, and Robert Kirkby. "Exercise dependence and overtraining: The physiological and psychological consequences of excessive exercise." Sports Medicine, training and rehabilitation 10.3 (2001): 199-222.
2. Mond, Jonathan M., et al. "An update on the definition of “excessive exercise” in eating disorders research." International Journal of Eating Disorders 39.2 (2006): 147-153.
3. Lehmann, M., et al. "Training-overtraining. A prospective, experimental study with experienced middle-and long-distance runners." International journal of sports medicine 12.05 (1991): 444-452.
4. Lehmann, M., et al. "Training-overtraining: influence of a defined increase in training volume vs training intensity on performance, catecholamines and some metabolic parameters in experienced middle-and long-distance runners." European journal of applied physiology and occupational physiology 64.2 (1992): 169-177.
5. Fry, Andrew C., and William J. Kraemer. "Resistance exercise overtraining and overreaching." Sports medicine 23.2 (1997): 106-129.
6. Pedersen, B. K., T. Rohde, and M. Zacho. "Immunity in athletes." The Journal of sports medicine and physical fitness 36.4 (1996): 236-245.
7. Shephard, R. J., and P. N. Shek. "Heavy exercise, nutrition and immune function: is there a connection?." International journal of sports medicine16.08 (1995): 491-497.
8. Hackney, Anthony C., Silas N. Pearman III, and Janice M. Nowacki. "Physiological profiles of overtrained and stale athletes: A review." Journal of Applied Sport Psychology 2.1 (1990): 21-33.
9. Fry, R. W., et al. "Psychological and immunological correlates of acute overtraining." British Journal of Sports Medicine 28.4 (1994): 241-246.
10. Silva III, John M. "An analysis of the training stress syndrome in competitive athletics." Journal of Applied Sport Psychology 2.1 (1990): 5-20.