title: Skeletal muscle homeostasis and plasticity in youth and ageing: impact of nutrition and exercise.
abstract: Skeletal muscles comprise a substantial portion of whole body mass and are integral for locomotion and metabolic health. Increasing age is associated with declines in both muscle mass and function (e.g. strength-related performance, power) with declines in muscle function quantitatively outweighing those in muscle volume. The mechanisms behind these declines are multi-faceted involving both intrinsic age-related metabolic dysregulation and environmental influences such as nutritional and physical activity. Ageing is associated with a degree of 'anabolic resistance' to these key environmental inputs, which likely accelerates the intrinsic processes driving ageing. On this basis, strategies to sensitize and/or promote anabolic responses to nutrition and physical activity are likely to be imperative in alleviating the progression and trajectory of sarcopenia. Both resistance- and aerobic-type exercises are likely to confer functional and health benefits in older age, and a clutch of research suggests that enhancement of anabolic responsiveness to exercise and/or nutrition may be achieved by optimizing modifications of muscle-loading paradigms (workload, volume, blood flow restriction) or nutritional support (e.g. essential amino acid/leucine) patterns. Nonetheless, more work is needed in which a more holistic view in ageing studies is taken into account. This should include improved characterization of older study recruits, that is physical activity/nutritional behaviours, to limit confounding variables influencing whether findings are attributable to age, or other environmental influences. Nonetheless, on balance, ageing is associated with declines in muscle mass and function and a partially related decline in aerobic capacity. There is also good evidence that metabolic flexibility is impaired in older age.
authors.affiliation: MRC-ARUK Centre of Excellence for Musculoskeletal Ageing Research, Clinical Metabolic and Molecular Physiology, University of Nottingham, Royal Derby Hospital Centre, Derby, UK.
authors.forename: M S
authors.initials: MS
authors.lastname: Brook
authors.affiliation: MRC-ARUK Centre of Excellence for Musculoskeletal Ageing Research, Clinical Metabolic and Molecular Physiology, University of Nottingham, Royal Derby Hospital Centre, Derby, UK.
authors.forename: D J
authors.initials: DJ
authors.lastname: Wilkinson
authors.affiliation: MRC-ARUK Centre of Excellence for Musculoskeletal Ageing Research, Clinical Metabolic and Molecular Physiology, University of Nottingham, Royal Derby Hospital Centre, Derby, UK.
authors.forename: B E
authors.initials: BE
authors.lastname: Phillips
authors.affiliation: MRC-ARUK Centre of Excellence for Musculoskeletal Ageing Research, School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, UK.
authors.forename: J
authors.initials: J
authors.lastname: Perez-Schindler
authors.affiliation: MRC-ARUK Centre of Excellence for Musculoskeletal Ageing Research, School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, UK.
authors.forename: A
authors.initials: A
authors.lastname: Philp
authors.affiliation: MRC-ARUK Centre of Excellence for Musculoskeletal Ageing Research, Clinical Metabolic and Molecular Physiology, University of Nottingham, Royal Derby Hospital Centre, Derby, UK.
authors.forename: K
authors.initials: K
authors.lastname: Smith
authors.affiliation: MRC-ARUK Centre of Excellence for Musculoskeletal Ageing Research, Clinical Metabolic and Molecular Physiology, University of Nottingham, Royal Derby Hospital Centre, Derby, UK.
authors.forename: P J
authors.initials: PJ
authors.lastname: Atherton
mesh_terms: D000375:Aging / Q000502:physiology*; D000818:Animals; D015444:Exercise / Q000502:physiology*; D006706:Homeostasis / Q000502:physiology*; D006801:Humans; D053580:Muscle Strength / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D009752:Nutritional Status / Q000502:physiology
keywords: ageing; muscle; protein turnover; substrate metabolism