HOW MUSCLES WORK: EXCESSIVE USE OF ENERGY
The only undesirable complication of excessive skeletal muscle contractions or exercise is that it results in the accumulation of lactic acid in muscles. Normally glucose is converted to carbon dioxide and water in the mitochondria using oxygen molecules (see page 19). When the muscles are very active, these mitochondria cannot work fast enough to meet the demand for energy molecules, and so the muscle tissue releases energy molecules by anaerobic (without oxygen) conversion of glucose into lactic acid and energy molecules. If the demand for energy molecules persists and the mitochondria cannot meet the demand because of inadequate oxygen supply the level of lactic acid rises. This results in changing the chemistry of muscle fibres and they stop contracting till the demand for oxygen supply is met and the mitochondria are able to convert lactic acid quickly into carbon dioxide and water. This by-product of incomplete combustion of glucose, lactic acid, is generally harmful to the body especially the heart tissue. Besides producing cramps, stiffness and aches in muscles, it slows down muscle function in general, leading to fatigue. The lactic acid level of blood is frequently checked in sportsmen during training to assess the state of muscle functioning and fitness.
*20\330\8*
Information on this site is provided for informational
purposes only. It is not meant to substitute for medical
advice provided by your physician or other medical
professional. You should not use the information contained
herein for diagnosing or treating a health problem or
disease, or prescribing any medication. You should read
carefully all product packaging and labels. If you have or
suspect that you have a medical problem, promptly contact
your physician or health care provider. Information and
statements regarding dietary supplements have not been
evaluated by the Food and Drug Administration and are not
intended to diagnose, treat, cure, or prevent any disease.
These statements have not been evaluated by the FDA and are not intended to diagnose, cure, treat or prevent disease. Consult a health professional if you have any questions.
