Rochester, Minnesota




The research interests of Jonathon (Jack) W. Senefeld, Ph.D., are centered on advancing the understanding of nonpharmacological interventions (such as exercise) to mitigate the detrimental effects of human aging and metabolic diseases. Specifically, Dr. Senefeld is interested in how skeletal muscle fatigue negatively influences exercise responses in older adults and people with diabetes, as well as how exercise training might improve these impaired responses.

Dr. Senefeld is also interested in how sex-specific mechanisms contribute to the etiologies of muscle fatigue and the physiological processes that limit human performance.

Focus areas

  • Physiology of aging. Human aging is associated with a gradual decline in skeletal muscle function and physical performance during both exercise and the activities of daily living. Using small biopsies of skeletal muscle to isolate mitochondria and small bundles of muscle fibers, Dr. Senefeld studies the mechanisms that contribute to the detrimental effects of human aging.
  • Impact of type 2 diabetes on physical performance. Metabolic dysregulation observed in human type 2 diabetes is associated with difficulty performing exercise training. Dr. Senefeld studies how fitness and skeletal muscle function influence physical performance in people with type 2 diabetes.
  • Sex-based differences in skeletal muscle physiology. Compared with men, women often have preserved skeletal muscle function during exercise and faster recovery after exercise. Dr. Senefeld is studying the mechanisms that drive these sex-based differences in skeletal muscle function and plans to use these findings to inform sex-specific prescriptions for exercise training.
  • Physiology of aging in elite athletes. Elite athletic performances are experiments in nature on the limits of human physiology across the life span and between men and women. Dr. Senefeld uses data from real-world competitions and physiological markers from elite athletes as predictive models of healthy human aging.

Significance to patient care

By studying how both skeletal muscle physiology and exercise performance are affected by aging, sex and disease, Dr. Senefeld gains insight into potential therapeutic targets for intervention. Dr. Senefeld aims to uncover novel therapeutic strategies to help delay or offset the negative effects of human aging and prevent the progression from prediabetes to diabetes.

Dr. Senefeld's research also provides insights into the many complex mechanisms that operate to keep humans healthy and able to adapt to exercise training.


Primary Appointment

  1. Associate Consultant I, Department of Anesthesiology and Perioperative Medicine

Administrative Appointment

  1. Associate Consultant I-Research, Department of Physiology & Biomedical Engineering

Academic Rank

  1. Assistant Professor of Physiology


  1. Postdoctoral Research Fellowship - Exercise physiology Department of Anesthesiology and Perioperative Medicine
  2. Postdoctoral Research Fellowship - Physical Therapy Marquette University
  3. Ph.D. - Clinical and Translational Rehabilitation Health Sciences: Richard W. Jobling Distinguished Research Assistant Marquette University
  4. BS - Exercise Physiology Marquette University

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