The Effects Of Overtraining

The most common mistake that athletes make is increasing their training by too much, too quickly.  Adding jumping or speed training and/or increasing your overall mileage too quickly can lead to stress fractures.  Changes in training should be done gradually.

Endurance sports such as triathlons, ultramarathon running and professional cycling have been associated with as much as a five-fold increase in the prevalence of atrial fibrillation (abnormal heart rhythms).  People who are super-fit are more likely to need pacemakers in old age because exercise causes changes in the body that can disrupt electrical pulses in the heart and lead to permanent structural changes to heart muscles, causing abnormal heart rhythms.

A 2016 study at the Technical University of Munich reported that young athletes who train excessively and don't leave enough time to recover from stress and injury have a 20% higher risk of suffering from depression due to changes in serotonin and tryptophan levels.

Cortisol – a hormone produced by the adrenal gland during periods of intense physical exercise – interferes with bone-building and reduces bone density by breaking down bone faster than it is made.

Cortisol – a hormone produced by the adrenal gland during periods of intense physical exercise – interferes with bone-building and reduces bone density by breaking down bone faster than it is made.

Very vigorous exercise and regular long-term heavy aerobic exercise can cause HDL levels to become especially elevated.  This is in keeping with the fact that exercise raises HDL levels, and demonstrates that overexertion produces further elevations.  It is unlikely that there are any negative effects from this elevation, only cardiovascular benefits.

A review of research evidence by US physicians published in the medical journal Mayo Clinic Proceedings in June of 2012 suggests that excess exercise (for example intensive training schedules or extreme endurance competitions) can cause dangerous long-term damage to the heart.  According to this review, the safe upper limit for heart health is a maximum of one hour of strenuous exercise a day, after which we reach a point of diminishing returns.

Since then, several studies have confirmed that the health benefits of exercise diminish for those who exercise excessively, for example among people who run more than 20 miles (32km) a week, more than six days a week, or faster than eight miles per hour (13kph).

During prolonged, intense exercise the body burns sugar and fat for fuel which creates free radicals as a byproduct.  Free radicals bind with cholesterol to create plaque buildup in the arteries which increases risk of developing heart disease.

According to research published in June, 2017 in the Australian sports journal Alimentary Pharmacology and Therapeutics, long periods of intense exercise can trigger Leaky Gut Syndrome.

Many young female athletes in training experience absent menstrual cycles due to low body fat content.  Exercising women with regular menstrual cycles and amenorrheic women who do not exercise excessively demonstrate a clear diurnal rhythm of leptin levels.  Exercising women with amenorrhea lose this normal rhythm, which raises the possibility that this cycle is important for the maintenance of reproductive function.  Leptin levels normally rise during the afternoon and reach a peak in the early hours of the morning, then decline towards dawn.

For some women, simply explaining the need for adequate calorific intake to match energy expenditure results in increased intake and/or reduced exercise, and their menses resume.  For those women in whom no other cause of amenorrhea can be found, but who are unable or unwilling to either increase food intake or decrease the amount of exercise, estrogen replacement therapy is strongly indicated.  Appropriate therapy consists of any estrogen replacement regimen that includes endometrial protection.

Exercise impairs the production of melatonin and exercising in the evening decreases melatonin for up to 3 hours afterwards.

Cortisol, which is a hormone emitted by the adrenal gland during periods of physical stress, has an immunosuppressive effect: high performance athletes have chronically lowered immune systems.  The high level of training leaves their immune systems frequently depressed so that, for example, if a group of athletes is training together, a flu bug will rapidly make its way around.  It is said that, in immunological terms, high-performance athletes are some of the least healthy people around.

During prolonged, intense exercise the body burns sugar and fat for fuel which creates free radicals as a byproduct.  Free radicals deplete the body's supply of antioxidants, which increases risk of developing various disease conditions.

"Rest" is not a dirty word!  Take a complete day off once a week.  And remember to take a vacation, sleep late once in a while, walk on the beach, or go out shopping for a day instead of doing time on the StairMaster.  Anything to break the cycle.  It will recharge you and get you back in the swing of things.  This is a simple problem to solve, and you can usually catch yourself in time before anything drastic happens.  Your bodily reserves are just like the batteries in your Walkman – after continued use, they are going to run out and you have to replace or recharge them if you want to keep hearing your favorite song.