Post by John A. Casler on Aug 12, 2007 10:37:53 GMT -8
Below is a "copy and paste" of a message sent by Jamie Carruthers of the SuperTraining list, dealing with timing of food/nutrient intake and training.
Thanks Jamie for finding this info.
Aging does not impair the anabolic response to a protein-rich
meal1,2,3
T Brock Symons, Scott E Schutzler, Tara L thingye, David L Chinkes,
Robert R Wolfe and Douglas Paddon-Jones
American Journal of Clinical Nutrition, Vol. 86, No. 2, 451-456,
August 2007
© 2007 American Society for Nutrition
Background: Sarcopenia is a debilitating condition afflicting the
elderly that may be facilitated by insufficient or ineffectual intake
of dietary protein. We previously showed that free-form essential
amino acids acutely stimulate muscle protein synthesis in both the
young and the elderly. However, the ability of an actual protein-rich
food to stimulate anabolism in the young and the elderly has not been
explored.
Objective: We aimed to characterize changes in plasma amino acid
concentrations and to quantify muscle protein synthesis in healthy
young (41 ± 8 y old; n = 10) and elderly (70 ± 5 y old; n = 10)
persons after ingestion of a 113-g (4-oz) serving of lean beef.
Design: Venous blood samples and vastus lateralis muscle biopsy
samples were obtained during a primed (2.0 µmol/kg) constant infusion
(0.08 µmol·kg-1·min-1) of L-[ring-13C6] phenylalanine. Plasma amino
acid concentrations were measured and a mixed-muscle fractional
synthesis rate (FSR) was calculated during the premeal period and for
5 h after beef ingestion.
Results: Mixed-muscle FSR increased by 51% in both the elderly (mean
± SE measurements: 0.072 ± 0.004%/h and 0.108 ± 0.006%/h before and
after the meal, respectively) and the young (0.074 ± 0.005%/h and
0.113 ± 0.005%/h before and after the meal, respectively) after beef
ingestion (P < 0.001). Plasma amino acid concentrations peaked at 100
min after beef ingestion in both age groups but were substantially
higher in the elderly (2185 ± 134 nmol/mL compared with 1403 ± 96
nmol/mL; P < 0.001).
Conclusion: Despite differences in the concentration of amino acids
in the plasma precursor pool, aging does not impair the ability to
acutely synthesize muscle protein after ingestion of a common protein-
rich food.
==================
Grandad, it ain't what you eat, it depends when you eat it - that's how muscles grow!
Journal of Physiology (2001), 535.1, pp. 2-2
Michael J. Rennie
The word 'sarcopenia' was coined to identify the condition of loss of skeletal muscle that occurs in wasting diseases and also during ageing. This loss of muscle constitutes a major problem for patients with a wide variety of chronic medical conditions including cancer, cardiovascular, respiratory and renal disease, and when it affects the respiratory muscles it prevents weaning from artificial respiration of patients in intensive care units. In the elderly, the maintenance of muscle strength is a major contributor to the ability to continue to carry out daily physical tasks successfully and safely. Naturally, many physiologists and rehabilitation experts have been drawn to the question of how to prevent the loss in muscle mass and possibly how to reverse it. There have now been over 50 studies carried out in older subjects, of ages up to 97 years! Most of these have demonstrated that resistance exercise can produce substantial increases in muscle strength and power and more limited, but nevertheless significant, increases in muscle mass and muscle fibre cross-sectional area (CSA) (Frontera et al. 1988; Skelton et al. 1995; Young, 1997). Nevertheless, it would make sense to find ways of increasing muscle mass in the elderly, not only because muscle strength and functionality would probably be improved more but also because of the attendant metabolic advantages in having a high lean to fat weight body ratio, including increases in glucose tolerance and the capacity to oxidize fat.
The paper published in this issue of The Journal of Physiology by Esmarck et al. (2001) provides us with some very interesting insights into the nutritional control of muscle mass. What Birgitte Esmarck and her colleagues have done is to demonstrate that, for the elderly, it matters considerably when a person eats a protein meal after having done some exercise. Delaying the consumption of a meal for 2 h after exercise limited the increase in muscle fibre growth after a programme of progressive resistance exercise in elderly men - of a mean age of 74 years. However, when the meal was taken immediately after exercise there was much greater efficacy in stimulating muscle growth, measured as increases in muscle fibre CSA (determined histochemically) and whole muscle CSA (determined by magnetic resonance imaging)........
=====================
Jamie Carruthers
Wakefield, UK
Thanks Jamie for finding this info.
Aging does not impair the anabolic response to a protein-rich
meal1,2,3
T Brock Symons, Scott E Schutzler, Tara L thingye, David L Chinkes,
Robert R Wolfe and Douglas Paddon-Jones
American Journal of Clinical Nutrition, Vol. 86, No. 2, 451-456,
August 2007
© 2007 American Society for Nutrition
Background: Sarcopenia is a debilitating condition afflicting the
elderly that may be facilitated by insufficient or ineffectual intake
of dietary protein. We previously showed that free-form essential
amino acids acutely stimulate muscle protein synthesis in both the
young and the elderly. However, the ability of an actual protein-rich
food to stimulate anabolism in the young and the elderly has not been
explored.
Objective: We aimed to characterize changes in plasma amino acid
concentrations and to quantify muscle protein synthesis in healthy
young (41 ± 8 y old; n = 10) and elderly (70 ± 5 y old; n = 10)
persons after ingestion of a 113-g (4-oz) serving of lean beef.
Design: Venous blood samples and vastus lateralis muscle biopsy
samples were obtained during a primed (2.0 µmol/kg) constant infusion
(0.08 µmol·kg-1·min-1) of L-[ring-13C6] phenylalanine. Plasma amino
acid concentrations were measured and a mixed-muscle fractional
synthesis rate (FSR) was calculated during the premeal period and for
5 h after beef ingestion.
Results: Mixed-muscle FSR increased by 51% in both the elderly (mean
± SE measurements: 0.072 ± 0.004%/h and 0.108 ± 0.006%/h before and
after the meal, respectively) and the young (0.074 ± 0.005%/h and
0.113 ± 0.005%/h before and after the meal, respectively) after beef
ingestion (P < 0.001). Plasma amino acid concentrations peaked at 100
min after beef ingestion in both age groups but were substantially
higher in the elderly (2185 ± 134 nmol/mL compared with 1403 ± 96
nmol/mL; P < 0.001).
Conclusion: Despite differences in the concentration of amino acids
in the plasma precursor pool, aging does not impair the ability to
acutely synthesize muscle protein after ingestion of a common protein-
rich food.
==================
Grandad, it ain't what you eat, it depends when you eat it - that's how muscles grow!
Journal of Physiology (2001), 535.1, pp. 2-2
Michael J. Rennie
The word 'sarcopenia' was coined to identify the condition of loss of skeletal muscle that occurs in wasting diseases and also during ageing. This loss of muscle constitutes a major problem for patients with a wide variety of chronic medical conditions including cancer, cardiovascular, respiratory and renal disease, and when it affects the respiratory muscles it prevents weaning from artificial respiration of patients in intensive care units. In the elderly, the maintenance of muscle strength is a major contributor to the ability to continue to carry out daily physical tasks successfully and safely. Naturally, many physiologists and rehabilitation experts have been drawn to the question of how to prevent the loss in muscle mass and possibly how to reverse it. There have now been over 50 studies carried out in older subjects, of ages up to 97 years! Most of these have demonstrated that resistance exercise can produce substantial increases in muscle strength and power and more limited, but nevertheless significant, increases in muscle mass and muscle fibre cross-sectional area (CSA) (Frontera et al. 1988; Skelton et al. 1995; Young, 1997). Nevertheless, it would make sense to find ways of increasing muscle mass in the elderly, not only because muscle strength and functionality would probably be improved more but also because of the attendant metabolic advantages in having a high lean to fat weight body ratio, including increases in glucose tolerance and the capacity to oxidize fat.
The paper published in this issue of The Journal of Physiology by Esmarck et al. (2001) provides us with some very interesting insights into the nutritional control of muscle mass. What Birgitte Esmarck and her colleagues have done is to demonstrate that, for the elderly, it matters considerably when a person eats a protein meal after having done some exercise. Delaying the consumption of a meal for 2 h after exercise limited the increase in muscle fibre growth after a programme of progressive resistance exercise in elderly men - of a mean age of 74 years. However, when the meal was taken immediately after exercise there was much greater efficacy in stimulating muscle growth, measured as increases in muscle fibre CSA (determined histochemically) and whole muscle CSA (determined by magnetic resonance imaging)........
=====================
Jamie Carruthers
Wakefield, UK