Post by John A. Casler on Nov 4, 2008 13:56:15 GMT -8
Another great ABSTRACT from Jamie Carruthers on SUPERTRAINING
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Effect of Resistance Exercise on Muscle Steroidogenesis
J Appl Physiol (October 2, 2008). doi:10.1152/japplphysiol.91235.2008
Jakob L. Vingren1, William J. Kraemer1*, Disa L. Hatfield1, Jeffrey
M. Anderson1, Jeff S. Volek1, Nicholas A. Ratamess2, Gwendolyn A.
Thomas1, Jen Y. Ho1, Maren S. Fragala1, and Carl M. Maresh1
Circulating testosterone is elevated acutely following resistance
exercise (RE) and is an important anabolic hormone for muscle
adaptations to resistance training.
The purpose of this study was to examine the acute effect of heavy RE
on intracrine muscle testosterone production in young resistance
trained men and women.
15 young highly resistance trained men (n=8; 21±1 years, 175.3±6.7
cm, 90.8±11.6 kg) and women (n=7; 24±5 years, 164.6±6.7 cm, 76.4±15.6
kg) completed 6 sets of 10 repetitions of Smith's machine squats with
80% of their 1-repetition maximum. Before RE, and 10 min and 70 min
after RE, muscle biopsies were obtained from the vastus lateralis.
Before RE, after 3 and 6 sets of squats, and 5, 15, 30 and 70 min
into recovery from RE blood samples were obtained using venipuncture
from an anticubital vein. Muscle samples were analyzed for
testosterone, 17 -hydroxysteroid dehydrogenase (HSD) type 3, and 3 -
HSD type 1-2 content. Blood samples were analyzed for the glucose and
lactate concentrations. No changes were found for muscle
testosterone, 3 -HSD1-2, and 17 -HSD3 concentrations. However, a
change in protein migration in the Bis-Tris gel was observed for 17 -
HSD3 post-exercise; this change in migration indicated ~2.8 kd
increase in molecular weight. These findings indicate that species
differences in muscle testosterone production may exist between rats
and humans.
In humans, muscle testosterone concentrations do not appear to be
affected by RE. This study expands on the current knowledge obtained
from animal studies by examining resting and post-exercise
concentrations of muscle testosterone and steroidogenic enzymes in
humans.
===================
========================================
Effect of Resistance Exercise on Muscle Steroidogenesis
J Appl Physiol (October 2, 2008). doi:10.1152/japplphysiol.91235.2008
Jakob L. Vingren1, William J. Kraemer1*, Disa L. Hatfield1, Jeffrey
M. Anderson1, Jeff S. Volek1, Nicholas A. Ratamess2, Gwendolyn A.
Thomas1, Jen Y. Ho1, Maren S. Fragala1, and Carl M. Maresh1
Circulating testosterone is elevated acutely following resistance
exercise (RE) and is an important anabolic hormone for muscle
adaptations to resistance training.
The purpose of this study was to examine the acute effect of heavy RE
on intracrine muscle testosterone production in young resistance
trained men and women.
15 young highly resistance trained men (n=8; 21±1 years, 175.3±6.7
cm, 90.8±11.6 kg) and women (n=7; 24±5 years, 164.6±6.7 cm, 76.4±15.6
kg) completed 6 sets of 10 repetitions of Smith's machine squats with
80% of their 1-repetition maximum. Before RE, and 10 min and 70 min
after RE, muscle biopsies were obtained from the vastus lateralis.
Before RE, after 3 and 6 sets of squats, and 5, 15, 30 and 70 min
into recovery from RE blood samples were obtained using venipuncture
from an anticubital vein. Muscle samples were analyzed for
testosterone, 17 -hydroxysteroid dehydrogenase (HSD) type 3, and 3 -
HSD type 1-2 content. Blood samples were analyzed for the glucose and
lactate concentrations. No changes were found for muscle
testosterone, 3 -HSD1-2, and 17 -HSD3 concentrations. However, a
change in protein migration in the Bis-Tris gel was observed for 17 -
HSD3 post-exercise; this change in migration indicated ~2.8 kd
increase in molecular weight. These findings indicate that species
differences in muscle testosterone production may exist between rats
and humans.
In humans, muscle testosterone concentrations do not appear to be
affected by RE. This study expands on the current knowledge obtained
from animal studies by examining resting and post-exercise
concentrations of muscle testosterone and steroidogenic enzymes in
humans.
===================