Aging and the Skeletal Muscle Angiogenic Response to Exercise in Women.

Whether aging lowers skeletal muscle basal capillarization and angiogenesis remains controversial. To investigate the effects of aging on skeletal muscle capillarization, eight young (YW) and eight aged (AW) women completed 8 weeks of exercise training. The response and relationships of muscle capillarization, interstitial vascular endothelial growth factor (VEGF), and microvascular blood flow to aerobic exercise training were investigated.

Collagen, cross-linking, and advanced glycation end products in aging human skeletal muscle.

We examined intramuscular endomysial collagen, cross-linking, and advanced glycation end products, as well as the general and contractile protein concentration of 20 young (25 +/- 3 yr) and 22 old (78 +/- 6 yr, range: 70-93 yr) sedentary men and women to better understand the underlying basis of changes in skeletal muscle mass and function that occur with aging. The old individuals had an impaired ability (increased time) (P < 0.05) to climb stairs (80%), rise from a chair (56%), and walk (44%), as well as lower (P < 0.

No difference in the skeletal muscle angiogenic response to aerobic exercise training between young and aged men.

Ischaemia-induced skeletal muscle angiogenesis is impaired in aged compared with young mice. In humans, vascular endothelial growth factor (VEGF) mRNA and protein following an acute exercise bout are lower in aged compared with young untrained men. We hypothesized that exercise-induced skeletal muscle angiogenesis would be attenuated in aged compared with young men.

Contractile and connective tissue protein content of human skeletal muscle: effects of 35 and 90 days of simulated microgravity and exercise countermeasures.

We examined the effects of 35 and 90 days of simulated microgravity with or without resistance-exercise (RE) countermeasures on the content of the general skeletal muscle protein fractions (mixed, sarcoplasmic, and myofibrillar) and specific proteins that are critical for muscle function (myosin, actin, and collagen). Subjects from two studies, using either unilateral lower limb suspension (ULLS) or bed rest (BR), comprised four separate groups: 35 days ULLS (n =11), 35 days ULLS+RE (n = 10), 90 days BR (n = 9), and 90 days BR+RE (n = 8). RE consisted of four sets of seven maximal concentric and eccentric repetitions of the quadriceps femoris muscles that were performed 2 or 3 times per week.

Concurrent exercise and muscle protein synthesis: implications for exercise countermeasures in space.

Introduction: Exercise countermeasures for long duration space crews incorporate aerobic and resistance exercise (i.e., concurrent training).

Contractile protein concentrations in human single muscle fibers.

The intent of this investigation was twofold: (1) to develop a convenient method for analyzing skeletal muscle protein concentrations in a large number of individual human single fibers and (2) to compare the myosin heavy chain (MHC) and actin concentrations in fibers expressing pure MHC I or MHC IIa. Individual vastus lateralis fibers were dissected from five individuals (3 M, 2 F; 24 +/- 1 years) and used to determine single fiber total protein (TP) concentration and MHC distribution. Fibers expressing pure MHC I and MHC IIa were further analyzed for MHC (252 fibers; mean of 50/subject) and actin (160 fibers; mean of 32/subject) concentration relative to TP.

Influence of creatine monohydrate ingestion on muscle metabolites and intense exercise capacity in individuals with multiple sclerosis.

Objective: To evaluate the effectiveness of ingesting creatine monohydrate in elevating intramuscular creatine stores and improving exercise capacity in individuals with multiple sclerosis (MS).

Design: Randomized, double-blind, placebo-controlled, pre-posttrial.

Setting: A university-based exercise physiology laboratory.

Titin and nebulin content in human skeletal muscle following eccentric resistance exercise.

We measured titin and nebulin content in muscle biopsies from the vastus lateralis before and 24 h after one bout of high-intensity eccentric knee extensor resistance exercise in seven men (26 +/- 3 years). Titin and nebulin content were significantly (P < 0.05) reduced after exercise by 30 and 15%, respectively.