Operation Everest II: Adaptations in Human Skeletal Muscle
40 days of progressive decompression to the stimulated altitude of the summit of Mt. Everest. Samples of the vastus lateralis muscle extracted before decompression (SL-1), at 380 and 282 Torr, and on return to sea level (SL-2) indicated that maximal activities of enzymes representative of the citric acid cycle, beta-oxidation, glycogenolysis, glycolysis, glucose phosphorylation, and high-energy phosphate transfer were unchanged (P greater than 0.05) at 380 and 282 Torr over initial SL-1 values. After exposure to 282 Torr, however, representing an additional period of approximately 7 days, reductions (P less than 0.05) were noted in succinic dehydrogenase (21%), citrate synthetase (37%), and hexokinase (53%) between SL-2 and 380 Torr. No changes were found in the other enzymes. 0.08) fibers between SL-1 and SL-2. This increase was mediated by a reduction in fiber area. No changes were found in fiber-type distribution (type I vs. These findings do not support the hypothesis, at least in humans, that, at the level of the muscle cell, extreme hypobaric hypoxia elicits adaptations directed toward maximizing oxidative function.
What Is Body Fat Percentage? What Is a Good Body Fat Percentage for a Male? What Are the Risks of High Body Fat? What Are the Risks of Low Body Fat? What Is a Realistic Body Fat Percentage? You’ve almost certainly heard the term ‘body fat percentage’ before, whether in conversation in the gym changing room, marketing fodder for fitness transformations, or even in a Men’s Health article. With a little bit of know how, the measure can act not just as a motivator on your fitness journey, but better yet, a dependable marker of health. But that begs the question, what is a healthy body fat percentage?
40 days of progressive decompression to the stimulated altitude of the summit of Mt. Everest. Samples of the vastus lateralis muscle extracted before decompression (SL-1), at 380 and 282 Torr, and on return to sea level (SL-2) indicated that maximal activities of enzymes representative of the citric acid cycle, beta-oxidation, glycogenolysis, glycolysis, glucose phosphorylation, and high-energy phosphate transfer were unchanged (P greater than 0.05) at 380 and 282 Torr over initial SL-1 values. After exposure to 282 Torr, however, representing an additional period of approximately 7 days, reductions (P less than 0.05) were noted in succinic dehydrogenase (21%), citrate synthetase (37%), and hexokinase (53%) between SL-2 and 380 Torr. No changes were found in the other enzymes. 0.08) fibers between SL-1 and SL-2. This increase was mediated by a reduction in fiber area. No changes were found in fiber-type distribution (type I vs. These findings do not support the hypothesis, at least in humans, that, at the level of the muscle cell, extreme hypobaric hypoxia elicits adaptations directed toward maximizing oxidative function.
What Is Body Fat Percentage? What Is a Good Body Fat Percentage for a Male? What Are the Risks of High Body Fat? What Are the Risks of Low Body Fat? What Is a Realistic Body Fat Percentage? You’ve almost certainly heard the term ‘body fat percentage’ before, whether in conversation in the gym changing room, marketing fodder for fitness transformations, or even in a Men’s Health article. With a little bit of know how, the measure can act not just as a motivator on your fitness journey, but better yet, a dependable marker of health. But that begs the question, what is a healthy body fat percentage?