Determinants of Skeletal Muscle Hypertrophy and the Attenuated Hypertrophic Response at Old Age
Determinants of Skeletal Muscle Hypertrophy and the Attenuated Hypertrophic Response at Old Age.
Journal of Sports Medicine & Doping Studies, pp. 2-9.
OMICS Publishing Group.
Official URL: http://www.omicsonline.org/2161-0673/pdfdownload.php?download=2161-0673-S1-003.pdf
In 2012 we will again see the impressive achievements of many athletes during the London Olympic Games. In
particular for weightlifters success is dependent on the power- and force-generating capacity of their muscles, which
in turn are strongly determined by muscle mass. Many athletes and bodybuilders therefore train intensively to develop
as much muscle hypertrophy as possible. Unlimited hypertrophy, however, is impossible. Limitations may be imposed
by the peak forces that the tendons, bones and joints can cope with, but also by factors within the muscles themselves.
For instance, an increase in pennation angle, which accompanies hypertrophy, beyond 450 would result in a reduction
in muscle strength even if muscle mass continuous to increase. There also is a trade-off between metabolism and
diffusion, where highly oxidative fibers require shorter diffusion distances, and hence smaller fibers, for adequate
oxygen supply to the mitochondria, than glycolytic fibers. A similar situation applies to the myonuclei where transcripts
are distributed over the cell mainly by diffusion and unbridled hypertrophy would, at least in theory, cause serious
problems with fiber maintenance. Despite these limiting factors muscles in bodybuilders can be as much as 74%
larger than in the normal population. Elderly people have a lower muscle mass that may cause problems with daily life
activities and an increase in muscle strength would improve their quality of life. There are indications, however, that
the maximal attainable hypertrophy is significantly reduced in the elderly. Here it is suggested that while individual
fibers in the elderly may hypertrophy to a similar extent as their younger counterparts, the age-related loss of muscle
fibers is an additional limiting factor of the whole muscle hypertrophy at old age.
|Title:||Determinants of Skeletal Muscle Hypertrophy and the Attenuated Hypertrophic Response at Old Age|
|Authors||Institution or Email of Authors|
|Date:||27 February 2012|
|Journal or Publication Title:||Journal of Sports Medicine & Doping Studies|
|Page Range:||pp. 2-9|
|Bunn, Jennifer A.||UNSPECIFIED|
|Publisher:||OMICS Publishing Group|
|Keywords:||Myonuclear domain; Microcirculation; Specific tension; Anatomy; Diffusion|
|HGF - Research field:||Aeronautics, Space and Transport|
|HGF - Program:||Space|
|HGF - Program Themes:||Research under Space Conditions|
|DLR - Research area:||Raumfahrt|
|DLR - Program:||R FR - Forschung unter Weltraumbedingungen|
|DLR - Research theme (Project):||R - Vorhaben Integrative Studien|
|Institutes and Institutions:||Institute of Aerospace Medicine > Space Physiology|
|Deposited On:||14 Sep 2012 11:59|
|Last Modified:||12 Dec 2013 21:45|
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