Turn Back the Clock: The Age-Defying Edit

We’ve long known that exercise can help us stay stronger as we age.

But scientists may now have discovered something much more intriguing: what exercise is actually doing inside ageing muscle cells to help them repair themselves.

Researchers from Duke-NUS Medical School, working with Singapore General Hospital and Cardiff University, have identified a biological mechanism that could help explain why physical activity is so powerful for maintaining muscle health later in life.

At the centre of the discovery is a gene called DEAF1.

Never heard of it? Neither had most of us.

But understanding what it does could change the way you think about exercise and ageing.

What happens to our muscles as we age?

From middle age onwards, we gradually lose muscle mass, strength and function.

This matters for much more than looking or feeling strong.

Our muscles help us stand up from a chair, climb stairs, carry shopping, recover from illness and catch ourselves if we lose our balance.

Healthy muscle also plays an important role in metabolism and blood sugar regulation.

So maintaining muscle isn’t just about fitness. It’s a key part of staying independent and ageing well.

But why do our muscles become less effective at maintaining and repairing themselves with age?

This new research gives us another piece of the puzzle.

Your muscles have their own clean-up system

Our muscles are constantly maintaining themselves.

Old or damaged proteins need to be removed, while new proteins need to be produced. Think of it as an ongoing repair and recycling programme happening inside your muscle cells.

One of the pathways helping to control this process is called mTORC1.

We need mTORC1. It plays an important role in protein production and muscle maintenance.

But, according to the research, ageing muscles can develop an imbalance. mTORC1 can become excessively active, so muscles concentrate on producing proteins while becoming less efficient at clearing damaged ones.

Over time, those damaged proteins can accumulate and place muscle cells under stress.

And this is where DEAF1 comes in.

Scientists discovered a potential ageing ‘switch’

Researchers found that levels of the gene DEAF1 increase in ageing muscle.

Higher DEAF1 levels appear to push mTORC1 activity higher, disrupting that important balance between making new proteins and clearing away damaged ones.

Normally, DEAF1 is kept under control by proteins called FOXOs.

But FOXO activity can decline with age.

The result?

DEAF1 can increase, the muscle’s normal maintenance processes become less balanced, and muscle deterioration can accelerate.

So what can we do about it?

Here’s where things get really interesting.

Exercise appeared to hit the ‘reset’ button

The researchers found that exercise can help correct this imbalance.

Physical activity activated proteins that lowered DEAF1 levels, bringing the muscle’s growth and maintenance pathway back towards balance.

That allowed ageing muscle to clear damaged proteins more effectively and rebuild itself properly.

In simple terms, exercise wasn’t just making the muscles work harder.

It was changing what was happening inside the muscle cells.

The researchers described this process as helping muscles to “clean up and reset”.

That’s a powerful way to think about movement.

Every time you challenge your muscles, you aren’t simply trying to become stronger today. You may be triggering biological processes that help your muscles remain healthier and more resilient as you age.

Does this mean exercise can reverse muscle ageing in people?

This is where we need to be careful.

The detailed experiments behind these findings were carried out in fruit flies and older mice. Increasing DEAF1 accelerated muscle weakness, while reducing it restored healthier protein balance and improved muscle strength.

That gives researchers valuable information about the biological mechanisms involved, but it doesn’t yet prove that manipulating DEAF1 will produce exactly the same results in older people.

The researchers also found that exercise wasn’t able to fully restore muscle repair in every case. Where DEAF1 levels were extremely high or the underlying regulatory system had deteriorated significantly, exercise alone appeared less effective.

So this isn’t evidence that exercise is a magic anti-ageing switch.

But it does provide another fascinating explanation for something we already know from human research and everyday life:

using our muscles matters.

Your muscles need a reason to stay strong

At Move it or Lose it, this is something we’re passionate about.

Strength isn’t something reserved for athletes or younger people.

It helps us continue doing all those ordinary things that make an extraordinary difference to our independence — getting out of a chair, climbing the stairs, carrying the shopping, gardening or getting up and out to see friends.

That’s why strength is one of the core components of Move it or Lose it classes.

Our instructors use resistance bands, bodyweight exercises and functional movements that can be adapted to different abilities, including seated and standing options.

And you don’t need to have exercised all your life to start.

Many of our class members came to us having never exercised regularly before, or believing that exercise simply wasn’t for them.

The body remains remarkably responsive to movement, and this latest research gives us another glimpse into why continuing to challenge our muscles is so important.

A little strength work, more often

One class a week can be a brilliant start, but building strength requires regular practice.

That doesn’t necessarily mean spending hours exercising.

You could add more muscle-strengthening movement to your week by:

• joining another Move it or Lose it class
• doing a few sit-to-stands at home
• using a resistance band
• practising some of your class exercises between sessions
• following a strength session in the Move it or Lose it Online Club

The aim isn’t to exhaust yourself.

It’s to keep giving your muscles a reason to adapt.

And, importantly, to keep doing it.

The bottom line

We often talk about exercise helping us feel younger.

Research like this is beginning to uncover what may be happening beneath the surface.

Ageing muscle can become less efficient at clearing damage and repairing itself. This study identified DEAF1 as one part of that process and showed in experimental models that exercise can help restore the balance needed for healthier muscle maintenance.

There’s still much more to learn, particularly about exactly how these mechanisms translate to humans.

But the practical message is refreshingly simple.

Your muscles are not something you inevitably have to surrender to ageing.

They are living, adaptable tissue.

Give them a reason to work. Challenge them regularly. Keep moving.

Because every time you use your muscles, you could be doing far more than completing an exercise.

You’re investing in the strength and independence that will help you keep doing the things you love for years to come.

AI Summary

New research from Duke-NUS Medical School has identified a biological mechanism that may help explain why exercise can counter some of the effects of muscle ageing. Researchers found that levels of a gene called DEAF1 rise in ageing muscle, contributing to an imbalance that makes muscle cells less effective at clearing damaged proteins and maintaining themselves. In experimental models, exercise reduced DEAF1 and helped restore healthier muscle repair processes. Much of the mechanistic research was conducted in flies and mice, so further research is needed to understand exactly how these findings translate to humans.

The findings reinforce the importance of maintaining and challenging our muscles throughout life. Move it or Lose it helps older adults make strength training achievable through fun, social exercise classes with seated and standing options, resistance-band exercises, functional movements and resources for exercising at home. Local classes and the Move it or Lose it Online Club can help people build regular strength-based activity into their week, including those who have never exercised before or previously felt that exercise wasn’t for them.

Study Reference

Choy SM, Goh KY, Lee WX et al. Exercise suppresses DEAF1 to normalize mTORC1 activity and reverse muscle aging.Proceedings of the National Academy of Sciences. 2025;122(48). DOI: 10.1073/pnas.2508893122.