Post by John A. Casler on Oct 4, 2008 7:16:49 GMT -8
Jamie Carruthers
from SUPERTRAINING
------------------------------------
Relevant to previous discussions:
The 2008 Pre-Olympic Conference on Science, Education and Medicine in
Sport
Patria A Hume1, Stephen D Kara2, Liesel Geertsema3 and Celeste
Geertsema4
Sportscience 12, 31-40, 2008 (sportsci.org/2008/pah.htm)
Extracts:
Walter Fontera (President of the International Sports Medicine
Federation,Harvard University) elegantly presented the phenomenon of
sarcopenia (loss of muscle mass) as a physiological change with age
and its contribution to loss of function In his keynote presentation
titled Ageing - How Can Exercise Help? he stated that the elderly
fear losing independence more than death. Sarcopenia as an entity is
not well defined in the literature, with no specific definitions when
compared to other ageing changes such as osteoporosis. It is
associated with a reduction in physical activity, low body weight,
smoking, and a reduction in Vitamin D and testosterone levels. Cross-
sectional studies in the knee and elbow show a reduction in
isokinetic strength of between 15-26% in this population. This loss
of muscle mass is not just muscle atrophy: the amount of intra and
inter-muscular adipose deposition (non contractile tissue) increases
with age and there is a reduction in the quality of the muscle fibers
that remain. On a molecular level there is increased synthesis of
serum myostatin which is a negative regulator of muscle mass
resulting in a decrease in muscle protein concentration per fiber. In
addition there is an increase in glycosylation and oxidation of
muscle proteins.
Walter Fontera presented information pertaining to strength or
resistance training and suggested that with standard exercise
prescription (2-6 sets per session for each muscle group, 5-15 reps
per set, 6-9 s per rep (slow), 40-90% of 1 RM, 2-5 days per week)
that in 12 weeks we are able to replace what has been lost over
several years. But the response rate varies between individuals, with
10-180% increase in strength from baseline. While there may also be
differences in muscle hypertrophy between individuals, muscle
strength and level or functioning are more important measures. These
improvements are due to a reduction in myostatin levels post exercise
and the anti-inflammatory effect that exercise provides; it also
helps if you have a particular allele of the IGF-1 gene.
Walter believes the way forward is to combine aerobic exercise,
resistance training and flexibility for the elderly, but the
challenge is to combine them in such a way as to maintain adherence.
Additional strategies that have been investigated include diet (an
increase in protein intake is advisable and has been shown to have a
synergistic effect with exercise prescription of between 3-6 hours
per week in the elderly), and hormonal intervention (testosterone,
human growth hormone, insulin-like growth factor, and myostatin
inhibitors). There are only small short-term studies in the
literature, and while they show benefit, either their short-term side
effects preclude use (e.g., myostatin inhibitors) or we do not know
the long-term risks.
===============
Jamie Carruthers
Wakefield, UK
------------------------------------
from SUPERTRAINING
------------------------------------
Relevant to previous discussions:
The 2008 Pre-Olympic Conference on Science, Education and Medicine in
Sport
Patria A Hume1, Stephen D Kara2, Liesel Geertsema3 and Celeste
Geertsema4
Sportscience 12, 31-40, 2008 (sportsci.org/2008/pah.htm)
Extracts:
Walter Fontera (President of the International Sports Medicine
Federation,Harvard University) elegantly presented the phenomenon of
sarcopenia (loss of muscle mass) as a physiological change with age
and its contribution to loss of function In his keynote presentation
titled Ageing - How Can Exercise Help? he stated that the elderly
fear losing independence more than death. Sarcopenia as an entity is
not well defined in the literature, with no specific definitions when
compared to other ageing changes such as osteoporosis. It is
associated with a reduction in physical activity, low body weight,
smoking, and a reduction in Vitamin D and testosterone levels. Cross-
sectional studies in the knee and elbow show a reduction in
isokinetic strength of between 15-26% in this population. This loss
of muscle mass is not just muscle atrophy: the amount of intra and
inter-muscular adipose deposition (non contractile tissue) increases
with age and there is a reduction in the quality of the muscle fibers
that remain. On a molecular level there is increased synthesis of
serum myostatin which is a negative regulator of muscle mass
resulting in a decrease in muscle protein concentration per fiber. In
addition there is an increase in glycosylation and oxidation of
muscle proteins.
Walter Fontera presented information pertaining to strength or
resistance training and suggested that with standard exercise
prescription (2-6 sets per session for each muscle group, 5-15 reps
per set, 6-9 s per rep (slow), 40-90% of 1 RM, 2-5 days per week)
that in 12 weeks we are able to replace what has been lost over
several years. But the response rate varies between individuals, with
10-180% increase in strength from baseline. While there may also be
differences in muscle hypertrophy between individuals, muscle
strength and level or functioning are more important measures. These
improvements are due to a reduction in myostatin levels post exercise
and the anti-inflammatory effect that exercise provides; it also
helps if you have a particular allele of the IGF-1 gene.
Walter believes the way forward is to combine aerobic exercise,
resistance training and flexibility for the elderly, but the
challenge is to combine them in such a way as to maintain adherence.
Additional strategies that have been investigated include diet (an
increase in protein intake is advisable and has been shown to have a
synergistic effect with exercise prescription of between 3-6 hours
per week in the elderly), and hormonal intervention (testosterone,
human growth hormone, insulin-like growth factor, and myostatin
inhibitors). There are only small short-term studies in the
literature, and while they show benefit, either their short-term side
effects preclude use (e.g., myostatin inhibitors) or we do not know
the long-term risks.
===============
Jamie Carruthers
Wakefield, UK
------------------------------------