The Underrated Superpower: Why Muscle Mass Extends Your Life

When we think about healthy aging, we think about what we eat, how we sleep, how we manage stress. All of these are incredibly important of course and as a nutritionist you might assume I’m biased. Yet the science is unambiguous: muscle mass is the single strongest predictor of how long we live and how well we live. And perhaps most surprisingly it directly shapes the health of our brain. This is why I now call it the underrated superpower. And it's available to every one of us.

The gap we're not talking about

We are living longer than any previous generation. But here's what the statistics don't celebrate: the average healthy lifespan in the UK is around 60 years vs. a life expectancy of roughly 80. That's two decades spent in declining health and reduced mobility.

This gap between how long we live and how well we live is what we call the healthspan gap. And closing it is perhaps the most important health conversation of our time.

As a nutritionist, I spent years focused on what I eat. But it was when I started lifting weights at 36 that I started seeing the biggest changes in my health and wellbeing. I saw the same thing in clinic. The more I worked with women in their 40s, 50s and beyong, the more one factor kept rising to the surface. Muscle mass.

What the science tells us

The evidence is striking and much of it is still surprising even to health professionals. Let’s take a look at it.

The CRONICAS Cohort Study, which followed over 3,200 people across eight years, found that each additional kilogram of muscle mass was associated with a 19% reduction in all-cause mortality. Those with the highest muscle mass had a 56% lower risk of death than those with the least. Crucially, body fat percentage was far less predictive. BMI alone tells us very little.

But the finding that stops people in their tracks is the connection between muscle and brain health.

A landmark study from the Rush Memory and Aging Project in Chicago followed 970 older adults over nearly four years. For every unit increase in muscle strength, the risk of developing Alzheimer's disease fell by 43%. The mechanism? Muscles produce myokines, anti-inflammatory messenger molecules that cross the blood-brain barrier and directly protect neural tissue. Your muscles and your brain are in constant conversation.

A twin study from King's College London adds another compelling layer. By comparing genetically identical twins who differed in leg strength, researchers were able to strip away the influence of genetics entirely. The twin with greater leg power consistently showed better cognitive function and brain structure a decade later. This isn't inheritance. It's modifiable. It's within our control.

Three levers worth pulling

Understanding the science is one thing. Knowing what to do with it is another. In my clinical work and in my own life I've come back to three practical pillars again and again.

Move with resistance. Strength training is the single most powerful intervention for preserving muscle mass as we age. You don't need a gym or a complicated programme. Two sessions a week, starting with bodyweight movements, squats, lunges, press-ups is enough to begin. The key is progressive overload: gradually increasing the challenge so the body has a reason to adapt. I started lifting weights in my mid 30s. Now at 41 I can confidently say it has changed my life more than any dietary intervention I have ever made.

Eat enough protein. Most women I see are significantly under-eating protein, particularly from their 40s onwards. As oestrogen declines, muscle becomes harder to retain, making adequate protein not a preference but a necessity. Aim for at least 1.2g per kilogram of body weight daily, spread across meals. Get the majority of your protein from food but using a good quality protein powder can be a simple way to help you reach your target. 

Find your community. Your environment is one of the strongest predictors of your long-term health outcomes. Behavioural science shows that humans are neurologically wired for social contagion, meaning habits, emotions, and even health behaviours spread through social networks. Studies from Harvard have found that nutrition and exercise habits as well as many other lifestyle factors associated with longevity are all significantly influenced by the people we surround ourselves with! When you spend time around people who prioritise movement, nutrition, and growth, those behaviors become normalised. Your brain adapts to the standards of your environment. Community isn’t just emotionally important, it’s biologically influential. The healthiest humans rarely do it alone. They build ecosystems that make healthy choices easier, more consistent, and more sustainable.

Protect your environment.

Your habits will follow.

Strength is not a privilege of youth

One of the most important things I want women to understand is this: it is never too late. The body responds to strength training at every age. Women in their 60s build muscle. Women in their 70s improve their balance and coordination. The physiological capacity is there.

What changes is the urgency. Every decade we wait, the work of rebuilding becomes harder. Every year we invest, the returns compound.

Muscle is not an aesthetic goal. It is not something reserved for athletes or the young or the naturally gifted. It is a biological foundation for energy, for independence, for cognitive health, for a life lived on your own terms.

The bravest thing you can do for your future self is to start building that foundation now. Not perfectly. Not all at once. Just start.