Resistance training enhances cellular recycling in muscle cells

A new study conducted at the University of Jyväskylä, Finland, has shown that resistance training among previously untrained men increases autophagosome content, but that this effect may be blunted by aging.

Credit: Kateryna Kon/

The autophagosome is a double-membrane secondary lysozyme involved in autophagy – the catabolic cellular route through which cytoplasmic cargo such as proteins and organelles are segregated and delivered for degradation by hydrolytic enzymes.

Pathological levels of autophagy are linked to muscle wasting, but physiological levels are required for cellular recycling.

As reported in a recent issue of the journal Acta Physiologica, Jaakko Hentilä and Academy of Finland Research Fellow Juha Hulmi, investigated indicators of autophagy and unfolded protein response (UPR) in muscle biopsies.

The UPR is an intracellular signaling pathway that maintains cellular homeostasis by transmitting information about protein folding status in the endoplasmic reticulum to the cytoplasm and nucleus.

This information triggers an adaptive response to correct any defects in proteins that are not folded correctly, as these could otherwise cause cell death (apoptosis). If the folding cannot be corrected, cells undergo apoptosis.

In the study, biopsies were taken from previously untrained young and older men after a single bout of resistance exercise and after 21 weeks of resistance training.

Hentilä and Hulmi suspected that aging may blunt some of the positive effects of resistance training induced improvement in muscle quality.

However, they found UPR induced by the accumulation of misfolded proteins in the ER was activated by a bout of unaccustomed resistance exercise, irrespective of the men’s age.

Skeletal muscle appeared to adapt to the resistance exercise similarly between the young and older men.

Sally Robertson

Written by

Sally Robertson

Sally has a Bachelor's Degree in Biomedical Sciences (B.Sc.). She is a specialist in reviewing and summarising the latest findings across all areas of medicine covered in major, high-impact, world-leading international medical journals, international press conferences and bulletins from governmental agencies and regulatory bodies. At News-Medical, Sally generates daily news features, life science articles and interview coverage.


Please use one of the following formats to cite this article in your essay, paper or report:

  • APA

    Robertson, Sally. (2019, June 20). Resistance training enhances cellular recycling in muscle cells. News-Medical. Retrieved on July 09, 2020 from

  • MLA

    Robertson, Sally. "Resistance training enhances cellular recycling in muscle cells". News-Medical. 09 July 2020. <>.

  • Chicago

    Robertson, Sally. "Resistance training enhances cellular recycling in muscle cells". News-Medical. (accessed July 09, 2020).

  • Harvard

    Robertson, Sally. 2019. Resistance training enhances cellular recycling in muscle cells. News-Medical, viewed 09 July 2020,


The opinions expressed here are the views of the writer and do not necessarily reflect the views and opinions of News Medical.
You might also like... ×
Significant number of COVID-19 positive cases asymptomatic, raising transmission concerns