title: Utilizing small nutrient compounds as enhancers of exercise-induced mitochondrial biogenesis.
abstract: Endurance exercise, when performed regularly as part of a training program, leads to increases in whole-body and skeletal muscle-specific oxidative capacity. At the cellular level, this adaptive response is manifested by an increased number of oxidative fibers (Type I and IIA myosin heavy chain), an increase in capillarity and an increase in mitochondrial biogenesis. The increase in mitochondrial biogenesis (increased volume and functional capacity) is fundamentally important as it leads to greater rates of oxidative phosphorylation and an improved capacity to utilize fatty acids during sub-maximal exercise. Given the importance of mitochondrial biogenesis for skeletal muscle performance, considerable attention has been given to understanding the molecular cues stimulated by endurance exercise that culminate in this adaptive response. In turn, this research has led to the identification of pharmaceutical compounds and small nutritional bioactive ingredients that appear able to amplify exercise-responsive signaling pathways in skeletal muscle. The aim of this review is to discuss these purported exercise mimetics and bioactive ingredients in the context of mitochondrial biogenesis in skeletal muscle. We will examine proposed modes of action, discuss evidence of application in skeletal muscle in vivo and finally comment on the feasibility of such approaches to support endurance-training applications in humans.
authors.affiliation: MRC Arthritis Research UK Centre for Musculoskeletal Ageing Research, School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham Birmingham, UK.
authors.forename: Daniel M
authors.initials: DM
authors.lastname: Craig
authors.affiliation: MRC Arthritis Research UK Centre for Musculoskeletal Ageing Research, School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham Birmingham, UK.
authors.forename: Stephen P
authors.initials: SP
authors.lastname: Ashcroft
authors.affiliation: Molecular, Cell and Cancer Biology, University of Massachusetts Medical School Worcester, MA, USA.
authors.forename: Micah Y
authors.initials: MY
authors.lastname: Belew
authors.affiliation: MRC Arthritis Research UK Centre for Musculoskeletal Ageing Research, School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham Birmingham, UK.
authors.forename: Ben
authors.initials: B
authors.lastname: Stocks
authors.affiliation: EIS Performance Centre, English Institute of Sport, Loughborough University Loughborough, UK.
authors.forename: Kevin
authors.initials: K
authors.lastname: Currell
authors.affiliation: Neurobiology, Physiology and Behavior, University of California Davis Davis, CA, USA.
authors.forename: Keith
authors.initials: K
authors.lastname: Baar
authors.affiliation: MRC Arthritis Research UK Centre for Musculoskeletal Ageing Research, School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham Birmingham, UK.
authors.forename: Andrew
authors.initials: A
authors.lastname: Philp
keywords: bioactives; exercise mimetics; mitochondrial biogenesis; nutraceuticals; skeletal muscle