Effect of Exercise on Muscle Fibre Size

2015 ◽  
pp. 103-113 ◽  
Author(s):  
G. Goldspink ◽  
K. F. Howells ◽  
P. S. Ward
Keyword(s):  
Muscle Fibre ◽  
Muscle Fibre Size ◽  
Fibre Size

scholarly journals Resistance Training and Testosterone Levels in Male Patients with Chronic Kidney Disease Undergoing Dialysis

2014 ◽  
Vol 2014 ◽  
pp. 1-7
Author(s):  
Stig Molsted ◽  
Jesper L. Andersen ◽  
Inge Eidemak ◽  
Adrian P. Harrison ◽  
Niels Jørgensen
Keyword(s):  
Resistance Training ◽  
Muscle Fibre ◽  
Binding Protein ◽  
Muscle Fibres ◽  
Muscle Fibre Size ◽  
Testosterone Levels ◽  
Fibre Size ◽  
Igf Binding ◽  
Male Patients ◽  
Igf Binding Protein

Background.We investigated serum testosterone and insulin-like growth factor 1 (IGF-1) levels’ associations with muscle fibre size and resistance training in male dialysis patients.Methods.Male patients were included in a 16-week control period followed by 16 weeks of resistance training thrice weekly. Blood samples were obtained to analyse testosterone, luteinizing hormone (LH), IGF-1, and IGF-binding protein 3. Muscle fibres’ size was analysed in biopsies fromm. vastus lateralis.Results.The patients’ testosterone levels were within the normal range at baseline (n=20) (19.5 (8.2–52.1) nmol/L versus 17.6 (16.1–18.0), resp.) whereas LH levels were higher (13.0 (5.5–82.8) U/L versus 4.3 (3.3–4.6),P<0.001, resp.). IGF-1 and IGF-binding protein 3 levels were higher in the patients compared with reference values (203 (59–590) ng/mL versus 151 (128–276),P=0.014, and 5045 (3370–9370) ng/mL versus 3244 (3020–3983),P<0.001, resp.). All hormone levels and muscle fibre size (n=12) remained stable throughout the study. Age-adjusted IGF-1 was associated with type 1 and 2 fibre sizes (P<0.05).Conclusion.Patients’ total testosterone values were normal due to markedly increased LH values, which suggest a compensated primary insufficiency of the testosterone producing Leydig cell. Even though testosterone values were normal, resistance training was not associated with muscle hypertrophy. This trial is registered withISRCTN72099857.

The specificity of endurance training on muscular power and muscle fibre size

Ergonomics ◽  
1980 ◽  
Vol 23 (7) ◽  
pp. 667-678 ◽  
Author(s):  
STEFAN H. CONSTABLE ◽  
RICHARD L. COLLINS ◽  
GARY S. KRAHENBUHL
Keyword(s):  
Endurance Training ◽  
Muscle Fibre ◽  
Muscular Power ◽  
Muscle Fibre Size ◽  
Fibre Size

Relation between body size and muscle fibre diameter in the newborn lamb

1956 ◽  
Vol 47 (4) ◽  
pp. 449-455 ◽  
Author(s):  
D. M. Joubert
Keyword(s):  
Body Weight ◽  
Body Size ◽  
Muscle Fibre ◽  
Fibre Diameter ◽  
Rectus Femoris ◽  
Muscle Fibres ◽  
Muscle Fibre Size ◽  
Fibre Size ◽  
Ewe Lambs ◽  
Positive Correlations

1. An investigation is reported in which the relationship was examined between body size and muscle fibre size of nineteen newborn lambs and including twelve males and seven females. Body size was measured in terms of the dead body weight and that of the dressed carcass, while muscle fibre size was estimated on the basis of the mean crossdiameter of 150 fibres per lamb.2. It was shown that the dressing (or carcass) percentage tends to increase with an increase in body weight, from 42·26% at a body weight of 2000 g. to 49·04% at 7000 g.3. Of the 2850 cross-diameters recorded, the majority (33·8%) of the fibres measured between 8·0 and 9·6 μ, while individual fibres varied in size from 1·6 to 22·4 μ.4. Highly significant, positive correlations were shown to exist between both body (r = 0·996) and carcass (r = 0·946) weight, and mean muscle fibre diameter, indicating that differences in size between the lambs may be accounted for largely by corresponding variations in the size of individual muscle fibres.5. Of the three muscles sampled m. gastrocnemius had the largest mean fibre diameter (10·38μ), followed in decreasing order by m. rectus femoris (9·72 μ) and m. longissimus dorsi (9·09 μ). These inter-muscle differences were significant at the 1% level of probability.6. Ram lambs had significantly thicker muscle fibres (10·32 μ) than ewe lambs (8·72 μ), but also weighed the heavier and produced heavier dressed carcasses. Some evidence was produced, however, in support of the theory that at comparable weights males possess thinner individual, and therefore a greater number of fibres than females.

scholarly journals Using AAV vectors expressing the β2-adrenoceptor or associated Gα proteins to modulate skeletal muscle mass and muscle fibre size

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Adam Hagg ◽  
Timothy D. Colgan ◽  
Rachel E. Thomson ◽  
Hongwei Qian ◽  
Gordon S. Lynch ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscle Fibre ◽  
Muscle Mass ◽  
Skeletal Muscle Mass ◽  
Muscle Fibre Size ◽  
Fibre Size

scholarly journals Hindlimb muscle fibre size and glycogen stores in bank voles with increased aerobic exercise metabolism

2015 ◽  
Vol 219 (4) ◽  
pp. 470-473 ◽  
Author(s):  
Ewa Jaromin ◽  
Julia Wyszkowska ◽  
Anna Maria Labecka ◽  
Edyta Teresa Sadowska ◽  
Paweł Koteja
Keyword(s):  
Aerobic Exercise ◽  
Muscle Fibre ◽  
Muscle Fibre Size ◽  
Exercise Metabolism ◽  
Fibre Size ◽  
Bank Voles ◽  
Hindlimb Muscle ◽  
Glycogen Stores

scholarly journals Interleukin-6 and Vitamin D Status during High-Intensity Resistance Training in Patients with Chronic Kidney Disease

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Stig Molsted ◽  
Pia Eiken ◽  
Jesper L. Andersen ◽  
Inge Eidemak ◽  
Adrian P. Harrison
Keyword(s):  
Vitamin D ◽  
Resistance Training ◽  
Vitamin D Deficiency ◽  
Muscle Fibre ◽  
High Intensity ◽  
Muscle Power ◽  
Control Period ◽  
Dialysis Patients ◽  
Muscle Fibre Size ◽  
Fibre Size

Background. The aim of this study was to investigate IL-6 and 25-hydroxyvitamin D (25-OH D) associations with muscle size and muscle function in dialysis patients.Methods. Patients were included in a 16-week control period followed by 16 weeks of high-intensity resistance training thrice weekly. IL-6 and 25-OH D were analysed after an over-night fast. Muscle fibre size was analysed in biopsies fromm. vastus lateralis. Muscle power was tested using a Leg Extensor Power Rig.Results. Patients (n=36) with IL-6 ≥ 6.49 pg/ml (median) were older and had decreased muscle power and a reduced protein intake (P<0.05) compared with patients with IL-6 < 6.49 pg/ml. IL-6 was not associated with muscle fibre size. Vitamin D deficiency (25-OH D < 50 nmol/l) was present in 51% of the patients and not associated with muscle power. IL-6 remained unchanged during the training period, whilst muscle power increased by 20–23% (P<0.001).Conclusion. Elevated IL-6 values were associated with decreased muscle power but not with decreased muscle fibre size. Half of the patients were suffering from vitamin D deficiency, which was not associated with muscle power. IL-6 was unchanged by high-intensity resistance training in dialysis patients in this study.

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