Project R-17030

FIBER-POWER: Decoding fiber-type-specific mechanisms underlying impaired recovery of muscle power after disuse in older adults (Research)

Muscle disuse following injury or illness threatens functional independence in older adults and is a driver of sarcopenia. Although resistance training is the gold standard for rehabilitation, recovery of muscle mass and especially muscle power, the strongest predictor of independence, is often incomplete. Disuse disproportionately impairs velocity-dependent force production, yet the fiber-type-specific and molecular mechanisms underlying this deficit remain unclear, limiting targeted rehabilitation strategies. Using my expertise in single-fiber muscle biology, this project integrates muscle biology with in vivo functional profiling to identify mechanisms driving disuse-induced loss of muscle power. In WP I, healthy older adults (55–75 y) will undergo 14 days of unilateral knee immobilization followed by 6 weeks of power or hypertrophy training. Functional performance, torque–velocity profiles, muscle volume, and qerial muscle biopsies will be assessed. WP II will examine fiber-type-specific single-fiber contractile function and Ca2+ sensitivity. WP III will map fiber-type-specific (phospho)proteomic signatures using state-of-the-art Astral mass spectrometry. By integrating single-fiber mechanics with molecular profiling and functional outcomes, this project will identify the mechanisms that distinguish successful from incomplete recovery of maximal muscle power, providing a mechanistic foundation for optimizing geriatric rehabilitation.

01 November 2026 - 31 October 2030