Exercise as it relates to Disease/Obstructive Sleep apnea and exercise
The term sleep apnea or obstructive sleep apnea (OSA) first appeared in medical literature around the 1950’s. Patients were reported to have heavily decreased blood oxygen levels and many were suffering from congestive heart failure.   The term Pickwickian syndrome was used to describe obstructive sleep apnea by an early 20th century physician who drew a link between what he was seeing in his patients and the association with excessive day time sleepiness in overweight young people like the fat boy in the novel The Pickwick Papers by Charles Dickens. In his Novel Charles Dickens Accurately described the symptoms of sleep apnea.  The first sleep clinic was established at Stanford University in 1970 by William Dement and they were joined by Christian Guilleminault and concentrated mainly on Respiratory disorders during sleep.  It was not till the publication of Sullivan et al. paper in 1981 that sleep apnea and specifically CPAP treatment became more widely recognised. That is more than 30 years ago.
Hypertension , Depression  , Daytime sleepiness, fatigue and tiredness  , Poor concentration , Irritability and mood changes , Nocturia , Morning headaches , Impotence and reduced sex drive , Restless legs .
Causes and Treatment
OSA is caused when the soft tissue in the throat collapses and obstructs the airways which stops the normal flow of air to the lungs and this can be caused by a very small airway and abnormally large larynx,enlarged Tonsils, an enlarged jaw and/or obesity.
Theatment: 1. Positional devices:  2. PROVENT® THERAPY: 3. Mandibular Advancement Splints: 4. "Continuous Positive Airway Pressure" Therapy: Commonly referred to as CPAP therapy is the gold standard for non-invasive treatment of OSA. This is accomplished by forcing air into the airways by using a flow generator that is connected to a mask that is situated on the nose and/or nose and mouth.
Role of exercise in reducing the effects of Obstructive Sleep Apnoea
The only cause OSA that can be alleviated by exercise is Obesity. Two major comorbidities that OSA and Obesity have in common are hypertension and depression.   While obesity is the only cause that can be alleviated by adhering to a regular exercise program, there are a number of the comorbidities or symptoms that OSA and Obesity have in common that have generally been said to improve with increased physical activity and weight loss.  I have observed this to be true in a clinical setting where severely obese patients suffering from OSA were able to lose weight through regular diet and exercise after receiving treatment for OSA. After their weight was brought to within the normal range many of them were able to discontinue the use of CPAP therapy, many were able to go off medications for hypertension and they seemed happier and more hopeful.
Poirier et al. (2001) recommended that together with a controlled diet exercise that consists of long duration (90 -240 minutes) and low-intensity(30%-50% of VO2 MAX) is preferred for the loss of body fat. It is therefore recommended that patients suffering from OSA due to obesity aim engage in regular intensity exercise for at least 90 minutes per day. As it can be extremely difficult for severely obese individuals participate in a lot of weight bearing exercise because of the strain placed on joints it would be advisable to start by walking and/or swimming. It would be wise to start with shorter periods, like 10mins twice a day, this will keep one from getting discouraged. The key is to stay consistent and as weight decreases and mobility increases this will become easier and one can increase the time and intensity of the exercise.