Not quite adapted to our cold weather yet and being a bit physically under-active, remiss, and negligent, I have been catching up on sports related mitochondrial information to share with our master age riders. As usual in the précis are offered as briefly as possible. I do include information origin for those who want to explorer full articles. Warning, there is a sad conclusion to my recent research, two actually. One, this holiday I must cut my caloric consumption a minimum of twenty percent at each meal, and two, I need to get back on the bike this afternoon, as soon as this is posted, even if it is only for an hour dirt ride. Well, the riding part is not sad… just cold.
Four definitions.
Biogenesis is the production of living matter parts, cell walls, DNA, enzymes, proteins, fats, etcetera.
Intramyocellular lipids are fats stored in droplets in muscle cells. An important muscle energy source.
Histological staining in vastus lateralis biopsies… Study of mitochondria involves removing a chunk, a very little chunk, of our largest quadriceps muscle, twice. Drop your hand down along side your leg, that muscle is the vastus lateralis. The muscle chunk is separated into all its parts, stained with different dyes to identify each part, and counting those parts, before testing and again after testing. One mitochondria, two mitochondria, three mitochondria, aw man, who bumped the table? One mitochondria, two mitochondria…
Mitochondria are responsible for the production of energy derived from the breakdown of carbohydrates and fatty acids. Mitochondria oxidize or “burn” carbohydrates, amino acids and fatty acids to create ATP, Adenosine Triphosphate, the cellular energy to, pump your heart, power brain neurons, contract muscles, exchange lung gases, extract nutrients from food, regulate body temperature, and everything else. This paragraph from an easily understood article with pictures is from a lifestyle and fitness organization, Fitstar. http://fitstar.com/high-intensity-exercise
Following snippets are from the Journal of Aging Research, Volume 2012 (2012), Article ID 194821, 20 pages, Article Skeletal Muscle Mitochondria and Aging: A Review, Courtney M. Peterson, Darcy L. Johannsen, and Eric Ravussin, Department of John S. Mclhenny Skeletal Muscle Physiology, Pennington Biomedical Research Center, 6400 Perkins Road, Baton Rouge, LA 70808, USA, Received 23 March 2012; Accepted 21 May 2012, Academic Editor: Holly M. Brown-Borg Copyright © 2012 Courtney M. Peterson et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. http://www.hindawi.com/journals/jar/2012/194821/
…independent of exercise training, simply living an active lifestyle may have a significant impact on mitochondrial function… strong evidence exercise training can improve mitochondrial function in elderly adults… Short et al. found that 4 months of aerobic exercise in older adults increased protein synthesis, mitochondrial enzyme activity, and biogenesis to levels similar in younger adults… Exercise has also been shown to increase the activity of antioxidant enzymes and heat shock proteins… decreasing the potential for mitochondrial oxidative damage thought to occur during aging.
Despite significant differences, most data show that some impairment remains… chronic exercise did not completely restore mitochondrial proteins, DNA content, and other factors to the levels of younger subjects, suggesting a persisting, independent effect of age. (Darn it, comment by me.)
Caloric Restriction (CR) which typically involves consuming 20–40% fewer calories than normal, also preserves mitochondrial health… CR is recognized as the most robust intervention that retards age-related deterioration due to negative lifestyle behaviors. Calorie restriction lowers energy expenditure by producing mitochondria that consume less oxygen yet are able to maintain normal levels of ATP production.
Finally, a few conclusions from a couple other footnoted research articles. Effects of Exercise on Mitochondrial Content and Function in Aging Human Skeletal Muscle. Journal Gerontology, … exercise enhances mitochondria activity in older human skeletal muscle… increases in mitochondria biogenesis… elicited mitochondrial adaptations that enhanced fatty acid oxidation capacity.
Subjects completed a 12-week exercise-training program… first 4 weeks, they exercised for 30 minutes at a heart rate corresponding to 50–60% of maximal aerobic capacity VO2max. For the next 4 weeks, they increased exercise time to 40 minutes at the same intensity, and for the last 4 weeks they increased the intensity to 70% of VO2max for at least 40 minutes per session.
Exercise Training Increases Intramyocellular Lipid (IMCL) and Oxidative Capacity in Older Adults. American Journal Physiological Endocrinol Metabolism, …exercise training increase both IMCL and the oxidative capacity of skeletal muscle in older (67.3 years), previously sedentary subjects… increased capacity for fat oxidation.
At baseline, participants were overweight but not obese, and were sedentary… improved physical fitness (VO2max) significantly by 15 ± 4% and without a change in body weight or % body fat… assess physical activity upon muscle mitochondria in elderly men and women… substantial mitochondria improvement, at least 50%.
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