It is suggested that there are different variations of overtraining, firstly monotonous program over training suggest that repetition of the same movement such as certain weight lifting and baseball batting can cause performance plateau due to an adaption of the central nervous system which results from a lack of stimulation. A second example of overtraining is described as chronic overwork type training where the subject may be training with too high intensity or high volume and not allowing sufficient recovery time for the body.
Overtraining can lead to exercise addiction which can lead to negative physiological and psychological effects, an addictive craving for physical activity is shown to lead to extreme exercise whilst building up a tolerance to the exercise then needing to go further levels to achieve the same high. Like pharmacological drugs, physical exercise may be chemically addictive. Addiction can be defined as, the frequent engaging in the behavior to a greater extent or for a longer time period than intended. It is theorized is that this addiction is due to natural endorphins and dopamine generated and regulated by the exercise. Whether strictly due to this chemical by-product or not, some people can be said to become addicted to or fixated on psychological/physical effects of physical exercise and fitness. This may lead to overexercise, resulting in the "overtraining" syndrome.
The frequency and amount of exercise also seems to impact outcomes in women pursuing IVF. Women who reported regular exercise had a similar live birth rate compared to women who did not exercise. Women who exercised 4 or more hours per week for 1–9 years were 40 % less likely to have a live birth, three times more likely to experience cycle cancellation , twice as likely to have an implantation failure or pregnancy loss compared to women who did not report exercise. However, compared to women who did not exercise, women who exercised regularly for 1–5 years were at greater risk for failure of cycle stimulation, implantation failure, and failure to develop a live birth after a chemical pregnancy.
It is quite common that athletes and non-athletes exceed the limits of their physical and psychological capacities causing the development of the overtraining syndrome, which is defined as the neuroendocrine disorder (hypothalamohypophysial), resulting from the imbalance between the demand of the exercise and the possibility of assimilation of the training, causing metabolic changes with consequences comprising not only the performance, but also other physiological and emotional aspects.
The high level of physical, sociocultural and psychic stress are factors that contribute to such outcome, as well as to neuroendocrine changes caused by nutritional aspects that lead to serotoninergic fluctuations.
Seeing as there are many non beneficial results of overtraining and the main treatment is taking time out to rest, so to avoid taking time off training prevention is very important for many athletes. An additional method preferred by many collegiate and professional level athletes is the incorporation of active recovery into training. The gradual varying of intensity and volume of training is an effective way to prevent overtraining.The athlete should be closely monitored by keeping records of weight, diet and heart rate and the training program should be adjusted in accordance to different physical and emotional stresses.
Exercise performed in different amounts and frequencies has varying effects on male and female fertility. The complex relationship between exercise and reproductive potential is likely due to alterations in the hypothalamic-pituitary axis. Extreme exercise may lead to anovulation and infertility, whereas exercise may result in improved ovulation and fertility in anovulatory obese patients. A large Norwegian study found that women who were active daily were 3.2 times more likely to have fertility problems than inactive women. Additionally, in women who exercised a moderate amount (either 16–30 min or 30–60 min), the risk of infertility was decreased compared to women who exercised < 15 min a day. Exercising to exhaustion was associated with an increased risk of infertility. The Nurses’ Health Study found that vigorous exercise for a minimum of 30 minutes a day was also associated with a decrease in ovulatory disorder infertility.
In contrast, regular exercise does not appear to affect semen parameters. A prospective study of men found that none of the semen parameters were altered with regular exercise, except bicycling >/= 5 hours a week was associated with low sperm concentration and low total motile sperm.
If woman is normal weight or underweight then strenuous exercise is detrimental. Women who do lots of physical activity are in fact considerably less fertile than those who do not do any at all.
The absence of a menstrual period in women of reproductive age.
An eating disorder characterized by the maintenance of a body weight below average, fear of gaining weight, and a distorted body image.
Male fertility diagnosis defined as a combination of low sperm concentration, reduced motility and abnormal sperm morphology in the ejaculate.
Light or infrequent menstrual ﬂow at intervals of 39 days to 6 months or 5–7 cycles in a year.
An abnormal enlargement of the pampiniform venous plexus in the scrotum.