title: Age-related decline in muscle mass and muscle function in Flemish Caucasians: a 10-year follow-up.
abstract: Aging is a complex process that is accompanied with changes in both muscle mass and muscle function (strength and performance). Therefore, the current longitudinal study aimed to provide a better insight in 10-year aging-related changes in whole-body muscle mass and strength performance of the leg extensors during the adult life span. Data were gathered within the framework of the first- (2002-2004: baseline) and third-generation Flemish Policy Research Center Sport (2012-2014: follow-up). Results are based on muscle characteristics data of 591 Flemish Caucasian adults (19-73 years, 381 men). Skeletal muscle mass (SMM) was determined with bioelectrical impedance analysis. Biodex Medical System 3® dynamometer was used to measure isometric (PTstatic120°) and isokinetic (PTdynamic60° and PTdynamic240°) strength, ballistic movement speed (S 20 %), and muscular endurance (work) of the knee extensors. Overall strength performance was higher at both evaluation moments in men compared to women (p < 0.01). But only S 20 % declined significantly faster in men compared to women (p < 0.01). Age and baseline strength performance were negatively related with the change in strength performance, even when corrected for SMM, protein intake, and energy expenditure during sports (E sport). In conclusion, strength performance was not associated with E sport in this study, but protein intake was associated with isometric strength in men, and with ballistic and isokinetic strength in women. Changes in S 20 % were significantly greater in men compared to women. Baseline values of strength performance and age were associated with changes in strength performance parameters, even after correction for SMM, protein intake, and E sport.
authors.affiliation: Faculty of Kinesiology and Rehabilitation Sciences, Department of Kinesiology, Physical Activity, Sports and Health Research Group, KU Leuven, Tervuursevest 101, 3001, Leuven, Belgium.
authors.forename: Ruben
authors.initials: R
authors.lastname: Charlier
authors.affiliation: Faculty of Kinesiology and Rehabilitation Sciences, Department of Kinesiology, Physical Activity, Sports and Health Research Group, KU Leuven, Tervuursevest 101, 3001, Leuven, Belgium.
authors.forename: Sara
authors.initials: S
authors.lastname: Knaeps
authors.affiliation: Faculty of Kinesiology and Rehabilitation Sciences, Department of Kinesiology, Physical Activity, Sports and Health Research Group, KU Leuven, Tervuursevest 101, 3001, Leuven, Belgium.|Faculty of Physical Education and Physiotherapy, Department of Human Biometrics and Biomechanics, Vrije Universiteit Brussel, Pleinlaan 2, 1050, Brussels, Belgium.
authors.forename: Evelien
authors.initials: E
authors.lastname: Mertens
authors.affiliation: Faculty of Kinesiology and Rehabilitation Sciences, Department of Kinesiology, Physical Activity, Sports and Health Research Group, KU Leuven, Tervuursevest 101, 3001, Leuven, Belgium.
authors.forename: Evelien
authors.initials: E
authors.lastname: Van Roie
authors.affiliation: Faculty of Kinesiology and Rehabilitation Sciences, Department of Kinesiology, Physical Activity, Sports and Health Research Group, KU Leuven, Tervuursevest 101, 3001, Leuven, Belgium.
authors.forename: Christophe
authors.initials: C
authors.lastname: Delecluse
authors.affiliation: Faculty of Kinesiology and Rehabilitation Sciences, Department of Kinesiology, Physical Activity, Sports and Health Research Group, KU Leuven, Tervuursevest 101, 3001, Leuven, Belgium.
authors.forename: Johan
authors.initials: J
authors.lastname: Lefevre
authors.affiliation: Faculty of Kinesiology and Rehabilitation Sciences, Department of Kinesiology, Physical Activity, Sports and Health Research Group, KU Leuven, Tervuursevest 101, 3001, Leuven, Belgium. martine.thomis@faber.kuleuven.be.
authors.forename: Martine
authors.initials: M
authors.lastname: Thomis
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology*; D001530:Belgium; D001823:Body Composition; D004734:Energy Metabolism / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D005544:Forecasting; D006801:Humans; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength; D018482:Muscle, Skeletal / Q000502:physiology*; D012189:Retrospective Studies; D044465:White People; D055815:Young Adult
keywords: Aging; Ballistic movement speed; Energy expenditure during sports; Muscle function; Muscle mass; Protein intake