Resistance and aerobic training in older men: effects onV˙o 2 peak and the capillary supply to skeletal muscle

1997 ◽  
Vol 82 (4) ◽  
pp. 1305-1310 ◽  
Author(s):  
R. T. Hepple ◽  
S. L. M. Mackinnon ◽  
J. M. Goodman ◽  
S. G. Thomas ◽  
M. J. Plyley
Keyword(s):  
Skeletal Muscle ◽  
Aerobic Training ◽  
Aerobic Power ◽  
Vastus Lateralis ◽  
Older Men ◽  
Capillary Density ◽  
Cycle Ergometer ◽  
Older Population ◽  
Capillary Supply

Hepple, R. T., S. L. M. Mackinnon, J. M. Goodman, S. G. Thomas, and M. J. Plyley. Resistance and aerobic training in older men: effects onV˙o 2 peak and the capillary supply to skeletal muscle. J. Appl. Physiol. 82(4): 1305–1310, 1997.—Both aerobic training (AT) and resistance training (RT) may increase aerobic power (V˙o 2 peak) in the older population; however, the role of changes in the capillary supply in this response has not been evaluated. Twenty healthy men (age 65–74 yr) engaged in either 9 wk of lower body RT followed by 9 wk of AT on a cycle ergometer (RT→AT group) or 18 wk of AT on a cycle ergometer (AT→AT group). RT was performed three times per week and consisted of three sets of four exercises at 6–12 repetitions maximum. AT was performed three times per week for 30 min at 60–70% heart rate reserve.V˙o 2 peak was increased after both RT and AT ( P < 0.05). Biopsies (vastus lateralis) revealed that the number of capillaries per fiber perimeter length was increased after both AT and RT ( P < 0.05), paralleling the changes in V˙o 2 peak, whereas capillary density was increased only after AT ( P < 0.01). These results, and the finding of a significant correlation between the change in capillary supply and V˙o 2 peak( r = 0.52), suggest the possibility that similar mechanisms may be involved in the increase ofV˙o 2 peak after high-intensity RT and AT in the older population.

Differing mechanisms of cold-induced changes in capillary supply in m. tibialis anterior of rats and hamsters

2002 ◽  
Vol 205 (6) ◽  
pp. 829-840 ◽  
Author(s):  
Durmus Deveci ◽  
Stuart Egginton
Keyword(s):  
Skeletal Muscle ◽  
Cold Acclimation ◽  
Oxygen Diffusion ◽  
Tibialis Anterior ◽  
Capillary Density ◽  
Disuse Atrophy ◽  
Diffusion Distance ◽  
Capillary Supply ◽  
Fibre Size ◽  
Anatomical Adaptations

SUMMARY The physiological, metabolic and anatomical adaptations of skeletal muscle to chronic cold exposure were investigated in Wistar rats (Rattus norvegicus), a species that defends core temperature, and Syrian hamsters (Mesocricetus auratus), which may adopt a lower set point under unfavourable conditions. Animals were exposed to a simulated onset of winter in an environmental chamber, progressively shortening photoperiod and reducing temperature from 12 h:12 h L:D and 22°C to 1 h:23 h L:D and 5°C over 4 weeks. The animals were left at 4°C for a further 4 weeks to complete the process of cold-acclimation. M. tibialis anterior from control (euthermic) and cold-acclimated animals of similar mass showed a significant hyperactivity-induced hypertrophy in the rat, but a small disuse atrophy in the hamster. Little evidence was found for interconversion among fibre types in skeletal muscle on cold-acclimation, and only modest differences were seen in activity of oxidative or glycolytic enzymes in either species. However, adjustments in Type II fibre size paralleled the muscle hypertrophy in rat and atrophy in hamster. Cold-induced angiogenesis was present in the rat, averaging a 28 % increase in capillary-to-fibre ratio (C:F) but, as this was balanced by fibre hypertrophy across the whole muscle, there was no change in capillary density (CD). In contrast, the C:F was similar in both groups of hamsters, whereas CD rose by 33 % in line with fibre atrophy. Within distinct regions of the m. tibialis anterior, there was a correlation between angiogenesis and fibre size in rats, in which oxygen diffusion distance increased, but not in hamsters, in which there was a reduced oxygen diffusion distance. Consequently, the change in C:F was greatest (39 %) in the glycolytic cortex region of the m. tibialis anterior in rats. We conclude that non-hibernator and hibernator rodents improve peripheral oxygen transport following cold-acclimation by different mechanisms. In rats, an increase in fibre girth was accompanied by a true angiogenesis, while the improved apparent capillary supply in hamsters was due to smaller fibre diameters. These responses are consistent with the strategies of resisting and accommodating, respectively, an annual fall in environmental temperature.

Impaired cardiac reserve and severely diminished skeletal muscle O2 utilization mediate exercise intolerance in Barth syndrome

2011 ◽  
Vol 301 (5) ◽  
pp. H2122-H2129 ◽  
Author(s):  
Carolyn T. Spencer ◽  
Barry J. Byrne ◽  
Randall M. Bryant ◽  
Renee Margossian ◽  
Melissa Maisenbacher ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Mitochondrial Myopathy ◽  
Near Infrared ◽  
Vastus Lateralis ◽  
Cycle Ergometer ◽  
Barth Syndrome ◽  
Exercise Intolerance ◽  
Peak Exercise ◽  
Vastus Lateralis Muscle ◽  
And Control

Barth syndrome (BTHS) is a mitochondrial myopathy characterized by reports of exercise intolerance. We sought to determine if 1) BTHS leads to abnormalities of skeletal muscle O2 extraction/utilization and 2) exercise intolerance in BTHS is related to impaired O2 extraction/utilization, impaired cardiac function, or both. Participants with BTHS (age: 17 ± 5 yr, n = 15) and control participants (age: 13 ± 4 yr, n = 9) underwent graded exercise testing on a cycle ergometer with continuous ECG and metabolic measurements. Echocardiography was performed at rest and at peak exercise. Near-infrared spectroscopy of the vastus lateralis muscle was continuously recorded for measurements of skeletal muscle O2 extraction. Adjusting for age, peak O2 consumption (16.5 ± 4.0 vs. 39.5 ± 12.3 ml·kg−1·min−1, P < 0.001) and peak work rate (58 ± 19 vs. 166 ± 60 W, P < 0.001) were significantly lower in BTHS than control participants. The percent increase from rest to peak exercise in ejection fraction (BTHS: 3 ± 10 vs. control: 19 ± 4%, P < 0.01) was blunted in BTHS compared with control participants. The muscle tissue O2 saturation change from rest to peak exercise was paradoxically opposite (BTHS: 8 ± 16 vs. control: −5 ± 9, P < 0.01), and the deoxyhemoglobin change was blunted (BTHS: 0 ± 12 vs. control: 10 ± 8, P < 0.09) in BTHS compared with control participants, indicating impaired skeletal muscle extraction in BTHS. In conclusion, severe exercise intolerance in BTHS is due to both cardiac and skeletal muscle impairments that are consistent with cardiac and skeletal mitochondrial myopathy. These findings provide further insight to the pathophysiology of BTHS.

Aging and assessment of physiological strain during exercise-heat stress

2002 ◽  
Vol 282 (4) ◽  
pp. R1063-R1069 ◽  
Author(s):  
Daniel S. Moran ◽  
W. Larry Kenney ◽  
Jane M. Pierzga ◽  
Kent B. Pandolf
Keyword(s):  
Heat Stress ◽  
Hormone Replacement Therapy ◽  
Replacement Therapy ◽  
Aerobic Training ◽  
Aerobic Power ◽  
Hormone Replacement ◽  
Cycle Ergometer ◽  
Maximal Aerobic Power ◽  
Physiological Strain ◽  
The Third

The purpose of this study was to evaluate the physiological strain index (PSI) for different age groups during exercise-heat stress (EHS). PSI was applied to three different databases. First, from young and middle-age men (21 ± 2 and 46 ± 5 yr, respectively) matched ( n = 9 each, P > 0.05) for maximal aerobic power. Subjects were heat acclimated by daily treadmill walking for two 50-min bouts separated by 10-min rest for 10 days in a hot-dry environment [49°C, 20% relative humidity (RH)]. The second database involved a group ( n = 8) of young (YA) and a group ( n = 7) of older (OA) men (26 ± 1 and 69 ± 1 yr, respectively) who underwent 16 wk of aerobic training and two control groups ( n = 7 each) who were matched for age to YA and OA. These four groups performed EHS at 36°C, 40% RH on a cycle ergometer for 60 min at 60% maximal aerobic power before and after training. The third database was obtained from three groups of postmenopausal women and a group of 10 men. Two groups of women ( n = 8 each) were undergoing hormone replacement therapy, estrogen or estrogen plus progesterone, and the third group ( n = 9) received no hormone replacement. Subjects were over 50 yr and performed the same EHS: exercising at 36°C, 40% RH on a cycle ergometer for 60 min. PSI assessed the strain for all three databases and reported differences were significant at P < 0.05. This index rated the strain in rank order, whereas the postacclimation and posttraining groups were assessed as having less strain than the preacclimation and pretraining groups. Furthermore, middle-aged women on estrogen replacement therapy had less strain than estrogen + progesterone and no hormone therapy. PSI evaluation was extended for men and women of different ages (50–70 yr) during acute EHS, heat acclimation, after aerobic training, and inclusive of women undergoing hormone replacement therapy.

Increases in human skeletal muscle Na(+)-K(+)-ATPase concentration with short-term training

1993 ◽  
Vol 264 (6) ◽  
pp. C1538-C1541 ◽  
Author(s):  
H. J. Green ◽  
E. R. Chin ◽  
M. Ball-Burnett ◽  
D. Ranney
Keyword(s):  
Skeletal Muscle ◽  
Aerobic Power ◽  
Vastus Lateralis ◽  
Vastus Lateralis Muscle ◽  
Ouabain Binding ◽  
Short Term ◽  
Vo2 Max ◽  
Continuous Exercise ◽  
Sufficient Intensity ◽  
K Concentration

To investigate the effect of short-term training on Na(+)-K(+)-adenosine triphosphatase (ATPase) concentration in skeletal muscle and on plasma K+ homeostasis during exercise, 9 subjects performed cycle exercise for 2 h per day for 6 consecutive days at 65% of maximal aerobic power (VO2 max). Na(+)-K(+)-ATPase concentration determined from biopsies obtained from the vastus lateralis muscle using the [3H]ouabain-binding technique increased 13.6% (P < 0.05) as a result of the training (339 +/- 16 vs. 385 +/- 19 pmol/g wet wt, means +/- SE). Increases in Na(+)-K(+)-ATPase concentration were accompanied by a small but significant increase in VO2 max (3.36 +/- 0.16 vs. 3.58 +/- 0.13 l/min). The increase in arterialized plasma K+ concentration and plasma K+ content determined during continuous exercise at three different intensities (60, 79, and 94% VO2 max) was depressed (P < 0.05) following training. These results indicate that not only is training capable of inducing an upregulation in sarcolemmal Na(+)-K(+)-ATPase concentration in humans, but provided that the exercise is of sufficient intensity and duration, the upregulation can occur within the first week of training. Moreover, our findings are consistent with the notion that the increase in Na(+)-K(+)-ATPase pump concentration attenuates the loss of K+ from the working muscle.

Aerobic Training Increases Expression Levels of SIRT3 and PGC-1α in Skeletal Muscle of Overweight Adolescents Without Change in Caloric Intake

2015 ◽  
Vol 27 (2) ◽  
pp. 177-184 ◽  
Author(s):  
Katya Vargas-Ortiz ◽  
Victoriano Perez-Vazquez ◽  
Francisco J. Diaz-Cisneros ◽  
Arturo Figueroa ◽  
Lizbeth M. Jiménez-Flores ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Aerobic Training ◽  
Vastus Lateralis ◽  
Caloric Intake ◽  
Peroxisome Proliferator ◽  
Maximal Heart Rate ◽  
Fat Percentage ◽  
Expression Levels ◽  
Before And After ◽  
Overweight Adolescents

Sirtuin 3 enzyme (SIRT3) is involved in the regulation of mitochondrial energy homeostasis by activating Peroxisome proliferator-activated receptor-gamma coactivator (PGC-1α). Murine models have shown that the protein SIRT3 was modified by exercise and diet, however, the effect of exercise without diet in humans has not been examined. Propose of this paper was to analyze the effect of aerobic training on SIRT3 and PGC-1α in skeletal muscle of overweight adolescents without change in caloric intake. Fourteen overweight or obese male adolescents (15.5 ± 0.8 years) trained 3 days-week/50 min x session, at 70-80% of maximal heart rate for 12 weeks. Anthropometrics and skeletal muscle biopsies from the vastus lateralis were taken before and after the exercise program to measure adiposity, SIRT3, and PGC-1α proteins. Peak aerobic capacity (VO2peak) was estimated before and after training. The participants did not change their eating habits during the intervention. SIRT3 (1.05 ± 0.11 vs. 1.25 ± 0.14 AU, p = .014) and PGC-1a (1.06 ± 0.15 Vs 1.39 ± 0.20 AU, p = .009) increased. Fat percentage and waist circumference decreased (p < .05). VO2peak increased after training (p < .001). There was a significant association between SIRT3 and PGC-1α after training program. These data suggest that aerobic training increased SIRT3 and PGC-1a expression levels in sedentary, overweight, or obese adolescents.

scholarly journals Super-relaxed state of myosin in human skeletal muscle is fiber-type dependent

2020 ◽  
Author(s):  
Lien A. Phung ◽  
Aurora D. Foster ◽  
Mark S. Miller ◽  
Dawn A. Lowe ◽  
David D. Thomas
Keyword(s):  
Skeletal Muscle ◽  
Human Skeletal Muscle ◽  
Fiber Type ◽  
Vastus Lateralis ◽  
Epifluorescence Microscopy ◽  
Model Organisms ◽  
Muscle Physiology ◽  
Fiber Types ◽  
Mhc I

AbstractThe myosin super-relaxed state (SRX) in skeletal muscle is hypothesized to play an important role in regulating muscle contractility and thermogenesis in humans, but has only been examined in model organisms. Here we report the first human skeletal muscle SRX measurements, using quantitative epifluorescence microscopy of fluorescent 2’/3’-O-(N-methylanthraniloyl) ATP (mantATP) single-nucleotide turnover. Myosin heavy chain (MHC) isoform expression was determined using gel electrophoresis for each permeabilized vastus lateralis fiber, to allow for novel comparisons of SRX between fiber-types. We find that the fraction of myosin in SRX is less in MHC IIA fibers than in MHC I and IIAX fibers (p = 0.008). ATP turnover of SRX is faster in MHC IIAX fibers compared to MHC I and IIA fibers (p = 0.001). We conclude that SRX biochemistry is measurable in human skeletal muscle, and our data indicate that SRX depends on fiber type as classified by MHC isoform. Extension from this preliminary work would provide further understanding regarding the role of SRX in human muscle physiology.

Seven days of exercise increase GLUT-4 protein content in human skeletal muscle

1995 ◽  
Vol 79 (6) ◽  
pp. 1936-1938 ◽  
Author(s):  
J. A. Houmard ◽  
M. S. Hickey ◽  
G. L. Tyndall ◽  
K. E. Gavigan ◽  
G. L. Dohm
Keyword(s):  
Skeletal Muscle ◽  
Exercise Training ◽  
Protein Content ◽  
Human Skeletal Muscle ◽  
Glucose Transporter ◽  
Vastus Lateralis ◽  
Cycle Ergometer ◽  
Maximal Heart Rate ◽  
Short Term ◽  
Glut 4

Insulin-responsive glucose transporter (GLUT-4) content increases by 1.8-fold in skeletal muscle with 14 wk of exercise training [Houmard et al. Am. J. Physiol. 264 (Endocrinol. Metab. 27): E896-E901, 1993]. The purpose of this study was to determine whether more short-term training (7 days) increases GLUT-4 protein content in human skeletal muscle. Seven sedentary men [25.0 +/- 1.1 (SE) yr, 44.1 +/- 2.2 ml.kg-1.min-1 maximal O2 uptake, 14.9 +/- 2.1% body fat] were examined before and after 7 days of cycle ergometer training (1 h/day, 76 +/- 2% maximal heart rate). Needle biopsy samples from the vastus lateralis were used to determine GLUT-4 protein content. Muscle GLUT-4 increased (P < 0.05) by an average of 2.8 +/- 0.5-fold with 7 days of training. GLUT-4 content in skeletal muscle thus increases substantially with short-term exercise training.

Malleability of human skeletal muscle Na+-K+-ATPase pump with short-term training

2004 ◽  
Vol 97 (1) ◽  
pp. 143-148 ◽  
Author(s):  
H. J. Green ◽  
D. J. Barr ◽  
J. R. Fowles ◽  
S. D. Sandiford ◽  
J. Ouyang
Keyword(s):  
Skeletal Muscle ◽  
Human Skeletal Muscle ◽  
Aerobic Power ◽  
Vastus Lateralis ◽  
Peak Oxygen Consumption ◽  
Rapid Adaptation ◽  
Ouabain Binding ◽  
Short Term ◽  
Power Peak ◽  
Phosphatase Assay

To investigate the hypothesis that short-term submaximal training would result in changes in Na+-K+-ATPase content, activity, and isoform distribution in skeletal muscle, seven healthy, untrained men [peak aerobic power (peak oxygen consumption; V̇o2 peak) = 45.6 ml·kg−1·min−1 (SE 5.4)] cycled for 2 h/day at 60–65% V̇o2 peak for 6 days. Muscle tissue, sampled from the vastus lateralis before training (0 days) and after 3 and 6 days of training and analyzed for Na+-K+-ATPase content, as assessed by the vanadate facilitated [3H]ouabain-binding technique, was increased ( P < 0.05) at 3 days (294 ± 8.6 pmol/g wet wt) and 6 days (308 ± 15 pmol/g wet wt) of training compared with 0 days (272 ± 9.7 pmol/g wet wt). Maximal Na+-K+-ATPase activity as evaluated by the 3- O-methylfluorescein phosphatase assay was increased ( P < 0.05) by 6 days (53.4 ± 5.9 nmol·h−1·mg protein−1) but not by 3 days (35.9 ± 4.5 nmol·h−1·mg protein−1) compared with 0 days (37.8 ± 3.7 nmol·h−1·mg protein−1) of training. Relative isoform distribution, measured by Western blot techniques, indicated increases ( P < 0.05) in α2-content by 3 days and β1-content by 6 days of training. These results indicate that prolonged aerobic exercise represents a potent stimulus for the rapid adaptation of Na+-K+-ATPase content, isoform, and activity characteristics.

scholarly journals Angiogenesis-related ultrastructural changes to capillaries in human skeletal muscle in response to endurance exercise

2015 ◽  
Vol 119 (10) ◽  
pp. 1118-1126 ◽  
Author(s):  
Oliver Baum ◽  
Jennifer Gübeli ◽  
Sebastian Frese ◽  
Eleonora Torchetti ◽  
Corinna Malik ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Cross Sections ◽  
Human Skeletal Muscle ◽  
Vastus Lateralis ◽  
Capillary Density ◽  
Volume Density ◽  
Ultrastructural Changes ◽  
Vastus Lateralis Muscle ◽  
Before And After ◽  
Exercise Induced

The ultrastructure of capillaries in skeletal muscle was morphometrically assessed in vastus lateralis muscle (VL) biopsies taken before and after exercise from 22 participants of two training studies. In study 1 (8 wk of ergometer training), light microscopy revealed capillary-fiber (C/F) ratio (+27%) and capillary density (+16%) to be higher ( P ≤ 0.05) in postexercise biopsies than in preexercise biopsies from all 10 participants. In study 2 (6 mo of moderate running), C/F ratio and capillary density were increased (+23% and +20%; respectively, P ≤ 0.05) in VL biopsies from 6 angiogenesis responders (AR) after training, whereas 6 nonangiogenesis responders (NR) showed nonsignificant changes in these structural indicators (−4%/−4%, respectively). Forty capillary profiles per participant were evaluated by point and intersection counting on cross sections after transmission electron microscopy. In study 1, volume density (Vv) and mean arithmetic thickness (T) of endothelial cells (ECs; +19%/+17%, respectively) and pericytes (PCs; +20%/+21%, respectively) were higher ( P ≤ 0.05), whereas Vv and T of the pericapillary basement membrane (BM) were −23%/−22% lower ( P ≤ 0.05), respectively, in posttraining biopsies. In study 2, exercise-related differences between AR and NR-groups were found for Vv and T of PCs (AR, +26%/+22%, respectively, both P ≤ 0.05; NR, +1%/−3%, respectively, both P > 0.05) and BM (AR, −14%/−13%, respectively, both P ≤ 0.05; NR, −9%/−11%, respectively, P = 0.07/0.10). Vv and T of ECs were higher (AR, +16%/+18%, respectively; NR, +6% /+6%, respectively; all P ≤ 0.05) in both groups. The PC coverage was higher (+13%, P ≤ 0.05) in VL biopsies of individuals in the AR group but nonsignificantly altered (+3%, P > 0.05) in those of the NR group after training. Our study suggests that intensified PC mobilization and BM thinning are related to exercise-induced angiogenesis in human skeletal muscle, whereas training per se induces EC-thickening.

Strength conditioning in older men: skeletal muscle hypertrophy and improved function

1988 ◽  
Vol 64 (3) ◽  
pp. 1038-1044 ◽  
Author(s):  
W. R. Frontera ◽  
C. N. Meredith ◽  
K. P. O'Reilly ◽  
H. G. Knuttgen ◽  
W. J. Evans
Keyword(s):  
Skeletal Muscle ◽  
Muscle Hypertrophy ◽  
Vastus Lateralis ◽  
Peak Torque ◽  
Older Men ◽  
Vastus Lateralis Muscle ◽  
Type I ◽  
Skeletal Muscle Function ◽  
Muscle Area ◽  
Fiber Area

The effects of strength conditioning on skeletal muscle function and mass were determined in older men. Twelve healthy untrained volunteers (age range 60-72 yr) participated in a 12-wk strength training program (8 repetitions/set; 3 sets/day; 3 days/wk) at 80% of the one repetition maximum (1 RM) for extensors and flexors of both knee joints. They were evaluated before the program and after 6 and 12 wk of training. Weekly measurements of 1 RM showed a progressive increase in strength in extensors and flexors. By 12 wk extensor and flexor strength had increased 107.4 (P less than 0.0001) and 226.7% (P less than 0.0001), respectively. Isokinetic peak torque of extensors and flexors measured on a Cybex II dynamometer increased 10.0 and 18.5% (P less than 0.05) at 60 degrees/s and 16.7 and 14.7% (P less than 0.05) at 240 degrees/s. The torque-velocity relationship showed an upward displacement of the curve at the end of training, mainly in the slow-velocity high-torque region. Midthigh composition from computerized tomographic scans showed an increase (P less than 0.01) in total thigh area (4.8%), total muscle area (11.4%), and quadriceps area (9.3%). Biopsies of the vastus lateralis muscle revealed similar increases (P less than 0.001) in type I fiber area (33.5%) and type II fiber area (27.6%). Daily excretion of urinary 3-methyl-L-histidine increased with training (P less than 0.05) by an average 40.8%. Strength gains in older men were associated with significant muscle hypertrophy and an increase in myofibrillar protein turnover.

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