SFU professors James Wakeling (left), a comparative biomechanist, and Nilima Nigam, a mathematician, have discovered the mechanics behind a natural physiological process that could compromise our mobility as we age and gain weight.


SFU study finds fat accumulation in human skeletal muscles concerning

July 28, 2015

By Carol Thorbes

Our efforts to battle the bulge and stay youthful aren’t futile but they are certainly compromised by a physiological process that undermines our mobility, according to a Simon Fraser University scientist.

James Wakeling, a comparative biomechanist in the Department of Biomedical Physiology and Kinesiology, and his research team are the first to isolate mechanisms that link intramuscular fat to reduced muscle performance.

They used a novel modeling approach to understand the effect of different distributions of fatty tissue within a muscle, on the mechanical output of that muscle.

Their research, published in the Journal of the Royal Society Interface, documents how our ability to perform everyday activities declines naturally with fat accumulation in human skeletal muscles. Aging, obesity and a variety of diseases worsen or advance this inevitable process. Human skeletal muscles are attached to bones by bundles of collagen fibres known as tendons. There are approximately 640 of them in our bodies.

“Accumulation of intramuscular fat seems to be ubiquitous during aging and for people with obesity,” says Wakeling.

“Understanding how this fat alters the ability of our muscles to develop force will mark an important step to help maintain mobility and a healthy lifestyle in all Canadians, even if we can’t halt the process completely.”

His team’s findings reveal a general deterioration in muscle quality due to fat infiltration. The infiltration alters muscle-tissue composition and consequently changes the way in which contractile forces are distributed through the muscle. This, in turn, substantially reduces muscle force as a whole.

Interdisciplinary collaboration with SFU math professor Nilima Nigam made this work possible. She helped develop the conceptual mathematical and computational models used in the study.

“This study highlighted, for me, the power of genuine interdisciplinary collaboration to answer deep conceptual questions,” says Nigam “We’ve used tools from physiology, mathematics, biomechanics and scientific computing to address questions that are of interest in public health.”

The Natural Sciences and Engineering Research Council of Canada funded this study.