The neuromuscular and skeletal muscle profile of a world class masters speed skater: A case study

Introduction: The age-related decline in neuromuscular function contributes to a loss of mobility and decreased quality of life. Insight on the physiological performance of masters athletes may enhance our understanding of the beneficial effects of exercise in older adults. However, the effects of aging on the neuromuscular capacity of masters athletes, particularly women, are not well known. Purpose: To investigate neuromuscular function and skeletal muscle characteristics of a 71-year-old female speed skater who is the current world-record holder in the 70+ age group for the 500m, 1000m, and sprint samalog. Methods: We performed a comprehensive assessment to measure cardiorespiratory fitness (VO 2peak via cycle ergometer), neuromuscular function (maximal force and power of the knee extensors), and fatigability (80 maximal velocity concentric contractions lifting a 20% maximal voluntary isometric contraction load). We obtained a muscle biopsy from the vastus lateralis to assess single fiber contractile properties, myosin heavy chain (MyHC) distribution and cross-sectional area. Results: Her relative VO 2peak of 39ml/kg/min (absolute 2.1L/min) was achieved at a peak workload of 200W. Her VO 2peak was >90 th percentile for women aged 30-39yrs 1 . Her power at the beginning of the dynamic exercise was markedly higher compared to older women aged 60-79yrs (130W vs. 87W) but considerably lower than young women (191W) 2 . Her fatigability (relative reduction in power) was markedly lower (13% vs. 32%) compared to this same cohort of older women and similar to women aged 19-28yrs (17%) 2 . Surprisingly, her MyHC I fibers were 35% larger (7424±2775μm 2 vs. 5233±1389μm 2 ) and considerably more abundant (71% vs. 29%) than her MyHC IIa fibers (n=451 fibers). Absolute fiber force of her MyHC I fibers was markedly higher compared to those from older (1.07mN vs. 0.61mN) and young women (0.58mN)(unpublished data). Absolute force of her MyHC II fibers was considerably higher than fibers from older women (0.84mN vs. 0.54mN) and similar to young women (0.84mN)(unpublished data). Specific force of her MyHC I fibers was similar to both older (107.8kN/m 2 vs. 108.3kN/m 2 ) and young women (108.7kN/m 2 ) (unpublished data). Additionally, specific force of her MyHC II fibers was similar to those from both older (148.6kN/m 2 vs. 152.7kN/m 2 ) and young women (150.9kN/m 2 ) (unpublished data). These data suggest that differences in absolute fiber force are explained entirely by differences in fiber size. Conclusion: We had the unique opportunity to assess the in vivo and ex vivo physiological performance of a world class masters speed skater. These data provide a physiological basis for her world class performance and underscores the importance of exercise in maintaining a high level of physical function with advancing age. References: 1. Kaminsky LA. et al. Mayo Clin Proc. (2022) 2. Sundberg CW. et al. J Appl Physiol. (2018). Supported by NIA R01 grant (AG048262) to CWS, SKH, and RHF. This abstract was presented at the American Physiology Summit 2025 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.