Lactic Acid Build-up in Muscles
http://www.lovemygym.com/articles/211/1/Lactic-Acid-Build-up-in-Muscles/Page1.html
Dr. Gabe Mirkin, M.D.
A practicing physician for more than 40 years and a radio talk show host for 25, Dr. Mirkin is a graduate of Harvard University and Baylor University College of Medicine. He is one of a very few doctors board-certified in four specialties: Sports Medicine, Allergy and Immunology, Pediatrics and Pediatric Immunology.
Dr. Mirkin's latest book is The Healthy Heart Miracle, published by HarperCollins. He wrote the chapter on sports injuries for the Merck Manual (both lay and physicians' editions), the largest selling book worldwide with over one million copies in print. His daily short features on fitness have been heard on CBS Radio News stations since the 1970's. He has written 16 books including The Sportsmedicine Book, the best-selling book on the subject that has been translated into many languages.
Dr. Mirkin did his residency at the Massachusetts General Hospital and over the years he has served as a Teaching Fellow at Johns Hopkins Medical School, Assistant Professor at the University of Maryland, and Associate Clinical Professor in Pediatrics at the Georgetown University School of Medicine.
Dr. Mirkin has run more than forty marathons and is now a serious tandem bike rider with his wife, Diana, often doing 30-60 miles in an outing. By Dr. Gabe Mirkin, M.D.
Published on 03/26/2006
Is lactic acid buildup in muscles harmful? Most exercisers are taught that lactic acid causes muscles to hurt and interferes with their ability to contract, so you feel tired. New research shows that muscles may contact more efficiently when lactic acid accumulates in them.
Lactic Acid Build-up in Muscles
When you exercise, your muscles burn sugar, fat or protein in the presence of oxygen to produce energy. If you exercise so intensely that you become very short of breath and your muscles can’t get enough oxygen, lactic acid accumulates in your muscle fibers. A study from Australia shows that lactic acid buildup in muscles does not make muscles tired and may even make muscle contract more efficiently, which may increase your endurance (Science, August 26, 2004.) This startling research contradicts what most instructors teach in their exercise classes.
The old theory was that lactic acid makes the muscles more acidic which causes them to hurt and burn and interferes with their ability to contract, so you feel tired. This new research shows that rat’s muscles contact more efficiently when lactic acid accumulates in them. Electric currents cause muscles to contract. This electricity is generated by cell membranes causing potassium to move inside cells and chloride ions to stay outside. With vigorous exercise, potassium ions accumulate outside cells. As large amounts of potassium ions accumulate outside cells, electricity is not generated and the cells cannot contract. Another ion called chloride accumulates outside cells and prevents potassium from getting back inside cells. Lactic acid removes the chloride, so it is easier for potassium to get back inside cells. Therefore lactic acid increases the ratio of potassium inside cells to the amount outside, and this helps the muscle contract with more efficiency.
While this new concept of how muscles use lactic acid for energy is reasonable, it is not likely to change the way athletes train or the way exercisers become more fit. Healthy people are supposed to exercise vigorously and feel a burn in their muscles during exercise, which signifies buildup of lactic acid in muscles. They feel sore on the next day, go easy for as many days as it takes for muscles to feel fresh again, and then exercise intensely again.
Dr. Gabe Mirkin has been a radio talk show host for 25 years and practicing physician for more than 40 years; he is board certified in four specialties, including sports medicine. Read or listen to hundreds of his fitness and health reports at http://www.DrMirkin.com
To receive Dr. Mirkin's free weekly e-Zine on fitness and health, send a blank email to subscribe@drmirkin.com
The old theory was that lactic acid makes the muscles more acidic which causes them to hurt and burn and interferes with their ability to contract, so you feel tired. This new research shows that rat’s muscles contact more efficiently when lactic acid accumulates in them. Electric currents cause muscles to contract. This electricity is generated by cell membranes causing potassium to move inside cells and chloride ions to stay outside. With vigorous exercise, potassium ions accumulate outside cells. As large amounts of potassium ions accumulate outside cells, electricity is not generated and the cells cannot contract. Another ion called chloride accumulates outside cells and prevents potassium from getting back inside cells. Lactic acid removes the chloride, so it is easier for potassium to get back inside cells. Therefore lactic acid increases the ratio of potassium inside cells to the amount outside, and this helps the muscle contract with more efficiency.
While this new concept of how muscles use lactic acid for energy is reasonable, it is not likely to change the way athletes train or the way exercisers become more fit. Healthy people are supposed to exercise vigorously and feel a burn in their muscles during exercise, which signifies buildup of lactic acid in muscles. They feel sore on the next day, go easy for as many days as it takes for muscles to feel fresh again, and then exercise intensely again.
Dr. Gabe Mirkin has been a radio talk show host for 25 years and practicing physician for more than 40 years; he is board certified in four specialties, including sports medicine. Read or listen to hundreds of his fitness and health reports at http://www.DrMirkin.com
To receive Dr. Mirkin's free weekly e-Zine on fitness and health, send a blank email to subscribe@drmirkin.com