Ten Weeks of Training Make Old Mice Less Frail
Graded Preliminary — the training effect was tested only in mice; the human data are a one-time comparison of 30 muscle samples and cannot show cause and effect.
Animal study. Findings may not carry over to people, which is why the grade is capped at Preliminary.
- Design
- Animal study
- Participants
- 61
- Duration
- 10 weeks
- Funding
- Instituto de Salud Carlos III (CIBERFES), Spanish Ministry of Science…
Exercise made old mice less frail, but only when the power plants of their muscle cells were working properly.
Losing muscle strength in later life makes people frail and erodes quality of life. In old mice, exercise pushed back against this decline. The key seemed to be the mitochondria, the power plants inside muscle cells. These stayed adaptable even in old age.
The researchers trained 20-month-old mice five days a week for ten weeks. The animals climbed ladders, balanced on a rotating rod and ran intervals on a treadmill. Afterward they performed as well as a mouse strain bred through a gene change to age especially well. They were less frail, and their muscles held more mitochondria. In mice whose muscle power plants were genetically impaired, training brought no gain in performance.
The team also studied muscle samples from 30 people aged 17 to 99 who were having surgery. Older people in poor physical shape had fewer and weaker mitochondria than older people in good shape. These human data come from a single snapshot of a small group. Whether exercise reduces frailty in older people through their mitochondria was not tested in humans.
Disclaimer: Research summaries are provided for informational purposes only and do not constitute medical advice. Always consult a qualified healthcare professional before making changes to your health routine.