Athlete's<unk>  is a result of dynamic physical activity, such as aerobic training more than 5 hours a week rather than static training such as weightlifting. During intensive prolonged endurance or strength training, the body signals the<unk>  to pump more blood through the body to counteract the oxygen deficit building in the skeletal muscles. Enlargement of the<unk>  is a natural physical adaptation of the body to deal with the high pressures and large amounts of blood that can affect the<unk>  during these periods of time. Over time, the body will increase both the chamber size of the left ventricle, and the muscle mass and wall thickness of the<unk> . Cardiac output, the amount of blood that leaves the<unk>  in a given time period (i.e. liters per minute), is proportional to both the chamber sizes of the<unk>  and the rate at which the<unk>  beats. With a larger left ventricle, the<unk>  rate can decrease and still maintain a level of cardiac output necessary for the body. Therefore, athletes with AHS commonly have lower resting<unk>  rates than nonathletes. The<unk>  becomes enlarged, or hypertrophic, due to intense cardiovascular workouts, creating an increase in stroke volume, an enlarged left ventricle (and right ventricle), and a decrease in resting pulse along with irregular rhythms. The wall of the left ventricle increases in size by about 15–20% of its normal capacity. No decrease of the diastolic function of the left ventricle occurs. The athlete may also experience an irregular<unk> beat and a resting pulse rate between 40 and 60 beats per minute (bradycardia). The level of physical activity in a person determines what physiological changes the<unk>  makes. The two types of exercise are static (strength-training) and dynamic (endurance-training). Static exercise consists of weight lifting and is mostly anaerobic, meaning the body does not rely on oxygen for performance. It also moderately increases<unk>  rate and stroke volume (oxygen debt). Dynamic exercises include running, swimming, skiing, rowing, and cycling, which rely on oxygen from the body. This type of exercise also increases both<unk>  rate and stroke volume of the<unk> . Both static and dynamic exercises involve the thickening of the left ventricular wall due to increased cardiac output, which leads to physiologic hypertrophy of the<unk> . Once athletes stop training, the<unk>  returns to its normal size.
Athletic heart syndrome
Hypertrophic cardiomyopathy
Bilharzial cor pulmonale
Left ventricular hypertrophy
Constrictive pericarditis
Wooden chest syndrome
Aicardi syndrome
Hantavirus pulmonary syndrome