Age-related changes in oxidative capacity differ between locomotory muscles and are associated with physical activity behavior.
Appl Physiol Nutr Metab
; 37(1): 88-99, 2012 Feb.
Article
en En
| MEDLINE
| ID: mdl-22236246
ABSTRACT
There is discrepancy in the literature regarding the degree to which old age affects muscle bioenergetics. These discrepancies are likely influenced by several factors, including variations in physical activity (PA) and differences in the muscle group investigated. To test the hypothesis that age may affect muscles differently, we quantified oxidative capacity of tibialis anterior (TA) and vastus lateralis (VL) muscles in healthy, relatively sedentary younger (8 YW, 8 YM; 21-35 years) and older (8 OW, 8 OM; 65-80 years) adults. To investigate the effect of physical activity on muscle oxidative capacity in older adults, we compared older sedentary women to older women with mild-to-moderate mobility impairment and lower physical activity (OIW, n = 7), and older sedentary men with older active male runners (OAM, n = 6). Oxidative capacity was measured in vivo as the rate constant, k(PCr), of postcontraction phosphocreatine recovery, obtained by (31)P magnetic resonance spectroscopy following maximal isometric contractions. While k(PCr) was higher in TA of older than activity-matched younger adults (28%; p = 0.03), older adults had lower k(PCr) in VL (23%; p = 0.04). In OIW compared with OW, k(PCr) was lower in VL (â¼45%; p = 0.01), but not different in TA. In contrast, OAM had higher k(PCr) than OM (p = 0.03) in both TA (41%) and VL (54%). In older adults, moderate-to-vigorous PA was positively associated with k(PCr) in VL (r = 0.65, p < 0.001) and TA (r = 0.41, p = 0.03). Collectively, these results indicate that age-related changes in oxidative capacity vary markedly between locomotory muscles, and that altered PA behavior may play a role in these changes.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Envejecimiento
/
Metabolismo Energético
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Músculo Cuádriceps
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Contracción Isométrica
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Locomoción
Tipo de estudio:
Prognostic_studies
/
Risk_factors_studies
Límite:
Adult
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Aged
/
Aged80
/
Female
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Humans
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Male
Idioma:
En
Revista:
Appl Physiol Nutr Metab
Asunto de la revista:
CIENCIAS DA NUTRICAO
/
FISIOLOGIA
/
MEDICINA ESPORTIVA
/
METABOLISMO
Año:
2012
Tipo del documento:
Article
País de afiliación:
Estados Unidos