High Endurance Exercise Causes Heart Damage

• Mitochondria make up, on average, about 1-2 percent of your skeletal muscle by volume, but this is generally enough to provide the needed energy for your daily movements
• Whereas your skeletal muscle contains only 1-2 percent mitochondria, your cardiac muscle may contain up to 35 percent
• This large volume of mitochondria supplies a steady source of energy right to your heart, and explains why your heart rarely needs to “rest” like your skeletal muscles do
• Extreme endurance exercise significantly increases cardiac output, which may put excessive strain on your heart depending on the duration and intensity of your activity
• Over-exercising, such as marathon running, may not make your heart feel tired like your other muscles, but it can cause scarring, inflammation, and other heart damage
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• Read more: http://fitness.mercola.com/sites/fitness/archive/2014/05/09/muscle-types-heart-health.aspx?e_cid=20140509Z1_DNL_art_2&utm_source=dnl&utm_medium=email&utm_content=art2&utm_campaign=20140509Z1&et_cid=DM45778&et_rid=515366959