PIPages
Labs

Christopher Sundberg

University of Wisconsin-Madison, WI·Physiology

As people age, their muscles shrink, a condition called sarcopenia. But their ability to produce power falls even faster, called dynapenia, and their muscles tire more quickly during movement.

Fields

Physiology

Medicine & Clinical Research

Biophysics

Topics

skeletal muscle

aging

sarcopenia

Grants
1 known grant, through Jan 2031

What they work on

  1. Measure how the protein content of slow and fast muscle fibers changes as they shrink with age in older males and females, using single-fiber proteomics and 3D fiber imaging on the same fibers.
  2. Determine whether age-related power loss in single fibers is driven by fiber size or by altered cross-bridge mechanics, the molecular contacts that generate force, by pairing contractile testing with 3D imaging or proteomics.
  3. Identify fiber type-specific protein profiles that predict whole-muscle weakness and fatigue in older adults, using machine learning.

More about the research

This limits mobility, raises the risk of falls and lowers quality of life. A likely piece of the puzzle is that aging affects slow and fast muscle fibers, the two main types of muscle cells, in different ways. After about 25 years of research, scientists still do not know how much power loss comes from fibers shrinking versus fibers working less well.

Why it matters

Weak, easily tired muscles make daily activities harder for adults aged 65 and older, especially women. Older adults with sarcopenia, power loss and fatigue may eventually benefit if this work identifies the proteins and fiber changes behind age-related muscle decline. Those proteins could become therapeutic targets for preventing loss of muscle size and function, and the work may reveal sex differences that affect treatment.

Known grants

From NIH and NSF research grants. Labs often have other funding we can't see.

Molecular Mechanisms of Fiber Type-Specific Skeletal Muscle Dysfunction with Aging

NIH · Feb 2026 – Jan 2031

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Sarah Lessard

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Determine how chronic hyperglycemia alters production of the extracellular matrix, the protein scaffold around muscle fibers, and how that changes the mechanical properties of skeletal muscle.

The school

University of Wisconsin-Madison: 91 labs on PI Pages, $1.9B a year on research, 854 research doctorates a year.

More about University of Wisconsin-Madison

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