Age and aerobic exercise training effects on whole body and muscle protein metabolism

Kevin R. Short, Janet L. Vittone, Maureen L. Bigelow, David N. Proctor, K Sreekumaran Nair

Research output: Contribution to journalArticle

286 Citations (Scopus)

Abstract

Aging in humans is associated with loss of lean body mass, but the causes are incompletely defined. Lean tissue mass and function depend on continuous rebuilding of proteins. We tested the hypotheses that whole body and mixed muscle protein metabolism declines with age in men and women and that aerobic exercise training would partly reverse this decline. Seventy-eight healthy, previously untrained men and women aged 19-87 yr were studied before and after 4 mo of bicycle training (up to 45 min at 80% peak heart rate, 3-4 days/wk) or control (flexibility) activity. At the whole body level, protein breakdown (measured as [13C]leucine and [15N]phenylalanine flux), Leu oxidation, and protein synthesis (nonoxidative Leu disposal) declined with age at a rate of 4-5% per decade (P < 0.001). Fat-free mass was closely correlated with protein turnover and declined 3% per decade (P < 0.001), but even after covariate adjustment for fat-free mass, the decline in protein turnover with age remained significant. There were no differences between men and women after adjustment for fat-free mass. Mixed muscle protein synthesis also declined with age 3.5% per decade (P < 0.05). Exercise training improved aerobic capacity 9% overall (P < 0.01), and mixed muscle protein synthesis increased 22% (P < 0.05), with no effect of age on the training response for either variable. Fat-free mass, whole body protein turnover, and resting metabolic rate were unchanged by training. We conclude that rates of whole body and muscle protein metabolism decline with age in men and women, thus indicating that there is a progressive decline in the body's remodeling processes with aging. This study also demonstrates that aerobic exercise can enhance muscle protein synthesis irrespective of age.

Original languageEnglish (US)
JournalAmerican Journal of Physiology - Endocrinology and Metabolism
Volume286
Issue number1 49-1
StatePublished - Jan 2004

Fingerprint

Muscle Proteins
Metabolism
Exercise
Fats
Proteins
Aging of materials
Basal Metabolism
Bicycles
Phenylalanine
Leucine
Heart Rate
Tissue
Fluxes
Oxidation

Keywords

  • Aging
  • Amino acid kinetics
  • Fractional synthesis rate
  • Leucine
  • Phenylalanine
  • Resting metabolic rate

ASJC Scopus subject areas

  • Biochemistry
  • Endocrinology
  • Physiology

Cite this

Age and aerobic exercise training effects on whole body and muscle protein metabolism. / Short, Kevin R.; Vittone, Janet L.; Bigelow, Maureen L.; Proctor, David N.; Nair, K Sreekumaran.

In: American Journal of Physiology - Endocrinology and Metabolism, Vol. 286, No. 1 49-1, 01.2004.

Research output: Contribution to journalArticle

Short, Kevin R. ; Vittone, Janet L. ; Bigelow, Maureen L. ; Proctor, David N. ; Nair, K Sreekumaran. / Age and aerobic exercise training effects on whole body and muscle protein metabolism. In: American Journal of Physiology - Endocrinology and Metabolism. 2004 ; Vol. 286, No. 1 49-1.
@article{87093dc6a0cf4b689d2ff4f1d5325471,
title = "Age and aerobic exercise training effects on whole body and muscle protein metabolism",
abstract = "Aging in humans is associated with loss of lean body mass, but the causes are incompletely defined. Lean tissue mass and function depend on continuous rebuilding of proteins. We tested the hypotheses that whole body and mixed muscle protein metabolism declines with age in men and women and that aerobic exercise training would partly reverse this decline. Seventy-eight healthy, previously untrained men and women aged 19-87 yr were studied before and after 4 mo of bicycle training (up to 45 min at 80{\%} peak heart rate, 3-4 days/wk) or control (flexibility) activity. At the whole body level, protein breakdown (measured as [13C]leucine and [15N]phenylalanine flux), Leu oxidation, and protein synthesis (nonoxidative Leu disposal) declined with age at a rate of 4-5{\%} per decade (P < 0.001). Fat-free mass was closely correlated with protein turnover and declined 3{\%} per decade (P < 0.001), but even after covariate adjustment for fat-free mass, the decline in protein turnover with age remained significant. There were no differences between men and women after adjustment for fat-free mass. Mixed muscle protein synthesis also declined with age 3.5{\%} per decade (P < 0.05). Exercise training improved aerobic capacity 9{\%} overall (P < 0.01), and mixed muscle protein synthesis increased 22{\%} (P < 0.05), with no effect of age on the training response for either variable. Fat-free mass, whole body protein turnover, and resting metabolic rate were unchanged by training. We conclude that rates of whole body and muscle protein metabolism decline with age in men and women, thus indicating that there is a progressive decline in the body's remodeling processes with aging. This study also demonstrates that aerobic exercise can enhance muscle protein synthesis irrespective of age.",
keywords = "Aging, Amino acid kinetics, Fractional synthesis rate, Leucine, Phenylalanine, Resting metabolic rate",
author = "Short, {Kevin R.} and Vittone, {Janet L.} and Bigelow, {Maureen L.} and Proctor, {David N.} and Nair, {K Sreekumaran}",
year = "2004",
month = "1",
language = "English (US)",
volume = "286",
journal = "American Journal of Physiology - Renal Fluid and Electrolyte Physiology",
issn = "1931-857X",
publisher = "American Physiological Society",
number = "1 49-1",

}

TY - JOUR

T1 - Age and aerobic exercise training effects on whole body and muscle protein metabolism

AU - Short, Kevin R.

AU - Vittone, Janet L.

AU - Bigelow, Maureen L.

AU - Proctor, David N.

AU - Nair, K Sreekumaran

PY - 2004/1

Y1 - 2004/1

N2 - Aging in humans is associated with loss of lean body mass, but the causes are incompletely defined. Lean tissue mass and function depend on continuous rebuilding of proteins. We tested the hypotheses that whole body and mixed muscle protein metabolism declines with age in men and women and that aerobic exercise training would partly reverse this decline. Seventy-eight healthy, previously untrained men and women aged 19-87 yr were studied before and after 4 mo of bicycle training (up to 45 min at 80% peak heart rate, 3-4 days/wk) or control (flexibility) activity. At the whole body level, protein breakdown (measured as [13C]leucine and [15N]phenylalanine flux), Leu oxidation, and protein synthesis (nonoxidative Leu disposal) declined with age at a rate of 4-5% per decade (P < 0.001). Fat-free mass was closely correlated with protein turnover and declined 3% per decade (P < 0.001), but even after covariate adjustment for fat-free mass, the decline in protein turnover with age remained significant. There were no differences between men and women after adjustment for fat-free mass. Mixed muscle protein synthesis also declined with age 3.5% per decade (P < 0.05). Exercise training improved aerobic capacity 9% overall (P < 0.01), and mixed muscle protein synthesis increased 22% (P < 0.05), with no effect of age on the training response for either variable. Fat-free mass, whole body protein turnover, and resting metabolic rate were unchanged by training. We conclude that rates of whole body and muscle protein metabolism decline with age in men and women, thus indicating that there is a progressive decline in the body's remodeling processes with aging. This study also demonstrates that aerobic exercise can enhance muscle protein synthesis irrespective of age.

AB - Aging in humans is associated with loss of lean body mass, but the causes are incompletely defined. Lean tissue mass and function depend on continuous rebuilding of proteins. We tested the hypotheses that whole body and mixed muscle protein metabolism declines with age in men and women and that aerobic exercise training would partly reverse this decline. Seventy-eight healthy, previously untrained men and women aged 19-87 yr were studied before and after 4 mo of bicycle training (up to 45 min at 80% peak heart rate, 3-4 days/wk) or control (flexibility) activity. At the whole body level, protein breakdown (measured as [13C]leucine and [15N]phenylalanine flux), Leu oxidation, and protein synthesis (nonoxidative Leu disposal) declined with age at a rate of 4-5% per decade (P < 0.001). Fat-free mass was closely correlated with protein turnover and declined 3% per decade (P < 0.001), but even after covariate adjustment for fat-free mass, the decline in protein turnover with age remained significant. There were no differences between men and women after adjustment for fat-free mass. Mixed muscle protein synthesis also declined with age 3.5% per decade (P < 0.05). Exercise training improved aerobic capacity 9% overall (P < 0.01), and mixed muscle protein synthesis increased 22% (P < 0.05), with no effect of age on the training response for either variable. Fat-free mass, whole body protein turnover, and resting metabolic rate were unchanged by training. We conclude that rates of whole body and muscle protein metabolism decline with age in men and women, thus indicating that there is a progressive decline in the body's remodeling processes with aging. This study also demonstrates that aerobic exercise can enhance muscle protein synthesis irrespective of age.

KW - Aging

KW - Amino acid kinetics

KW - Fractional synthesis rate

KW - Leucine

KW - Phenylalanine

KW - Resting metabolic rate

UR - http://www.scopus.com/inward/record.url?scp=0347417903&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0347417903&partnerID=8YFLogxK

M3 - Article

C2 - 14506079

AN - SCOPUS:0347417903

VL - 286

JO - American Journal of Physiology - Renal Fluid and Electrolyte Physiology

JF - American Journal of Physiology - Renal Fluid and Electrolyte Physiology

SN - 1931-857X

IS - 1 49-1

ER -