Simply living to 100 isn't the goal. The goal is to make as many of those years as possible healthy, active and worth living.

There is no guaranteed way to live to 100, but research into healthy ageing points to a consistent set of behaviours that can improve your chances of living longer and staying healthy and independent for more of those years. Regular physical activity, strength training, healthy eating, sufficient sleep, avoiding tobacco, maintaining relationships and managing your health risks all matter — and their benefits compound over decades.

Everyone wants to know the secret to living to 100. Is it exercise? A Mediterranean diet? Good genes? Sleep? Supplements? The latest longevity biohack?

The truth is less exciting — but more useful.

There is no single secret to reaching 100, and no lifestyle can guarantee how long you will live. But decades of research into healthy ageing point in a remarkably consistent direction: the choices you make over many years can influence your chances of living longer and, importantly, staying healthy and independent for more of those years. The National Institute on Aging identifies physical activity, healthy eating, sufficient sleep, avoiding tobacco, managing alcohol intake, regular healthcare and mental wellbeing among the factors that can support healthy ageing.

The goal shouldn't simply be to live to 100.

It should be to give yourself the best possible chance of reaching later life with your strength, fitness, cognitive function, independence and relationships intact.

That's the difference between lifespan and healthspan.

Key takeaways

• There is no guaranteed formula for living to 100. Genetics, environment, chance and medical events all matter.
• The fundamentals compound. Physical activity, strength, healthy eating, sleep, not smoking and preventive healthcare all contribute to healthier ageing.
• Healthspan matters as much as lifespan. The aim is not simply more years, but more years in which you can remain capable and independent.
• Relationships and purpose matter too. Longevity isn't just a physical optimisation problem.
• Think in decades, not days. Your future health is shaped by thousands of decisions accumulated over time.
• A long life also needs financial resilience. If you remain healthy and active into your 80s and 90s, your Wealthspan becomes part of the longevity equation.

What does it actually mean to "live to 100"?

Living to 100 is an extraordinary milestone. But a birthday doesn't tell you much about the quality of the years that preceded it. Someone can live a long life while spending many years managing illness or disability. Someone else may remain active, independent and engaged well into their 80s and 90s. That's why healthy ageing is about more than simply extending lifespan.

The World Health Organization describes healthy ageing in terms of maintaining the functional abilities that enable people to live well as they age. Physical activity and other health behaviours can contribute to maintaining that functional ability, mobility and independence.

So a better question than: "How can I live to 100?" is: "How can I increase my chances of living a long life while preserving the ability to enjoy it?"

That is a much more useful question.

There is no longevity hack

The modern longevity industry can make ageing seem like a problem waiting for the right technology to solve. There are fascinating developments in biomarkers, genetics, medicines and other interventions, and some may eventually prove transformative. But much of the evidence for healthy ageing still comes back to fundamentals.

The National Institute on Aging recommends staying active, making healthy food choices, getting enough sleep, limiting alcohol, avoiding tobacco and staying on top of appropriate healthcare as part of healthy ageing. That may sound obvious; it is also remarkably powerful.

A systematic review of 35 randomised controlled trials published between 2014 and 2024 found that multidimensional lifestyle interventions — including physical activity, nutrition, cognitive engagement and social connection — were associated with improvements across several healthy-ageing outcomes. The lesson isn't that any one behaviour guarantees longevity — it's that small advantages can compound over decades.

1. Build cardiovascular fitness

If you want to improve your chances of a long, capable life, fitness is one of the best places to start. Your cardiovascular system is fundamental to almost everything you want to do as you age: walking, climbing stairs, travelling, playing with grandchildren, carrying shopping, pursuing hobbies and remaining independent.

You don't need to become an elite athlete. The WHO recommends that adults get at least 150–300 minutes of moderate-intensity aerobic activity per week, or 75–150 minutes of vigorous activity, with additional benefits at higher levels. It also recommends muscle-strengthening activity involving the major muscle groups on at least two days per week. Walking counts. Cycling counts. Swimming counts. Running counts.

The best form of exercise is often the one you will actually keep doing. And if you're currently inactive, you don't need to start with the perfect programme. WHO guidance emphasises that some activity is better than none and recommends building up gradually. The goal isn't to win a fitness competition — it's to make your body capable of carrying you through the decades ahead.

For more info, start with Cardio: Why cardiovascular fitness is the strongest predictor of how long you'll live

2. Keep your strength

Cardiovascular fitness gets plenty of attention in longevity conversations, but strength training deserves just as much. Muscle isn't simply about appearance. Strength and physical function help determine whether you can continue doing ordinary things independently as you get older.

Getting out of a chair. Carrying luggage. Climbing stairs. Picking something up from the floor. Recovering from a fall. Continuing to travel. These are the capabilities that make independence possible.

WHO recommends muscle-strengthening activities involving the major muscle groups at least twice a week. For older adults, balance and functional activities become increasingly important too. You don't need to train like a bodybuilder, but you do need to give your muscles a reason to stay.

For more info, start with Strength: Why muscle mass is one of your most valuable long-term assets

3. Eat for the decades ahead

There is no single diet that guarantees longevity. Be suspicious of anyone who tells you otherwise.

But the broad nutritional principles are considerably less controversial than the diet wars suggest. A healthy diet should provide a wide variety of nutritious foods while helping you maintain a healthy body composition and reducing excessive intake of highly processed, energy-dense foods.

The National Institute on Aging highlights healthy eating patterns including Mediterranean-style approaches, which emphasise vegetables, fruit, whole grains, healthy fats and lean sources of protein. The important point is sustainability. The best diet isn't the one you follow perfectly for six weeks — it's the one you can still recognise twenty years from now.

For more info, see Nutrition: The longevity diet — what the science actually says

4. Don't smoke

If longevity had a list of non-negotiables, avoiding tobacco would be near the top. Smoking substantially increases the risk of major diseases, and quitting improves health even later in life. The National Institute on Aging notes that quitting smoking at any age can reduce the risk of cancer, heart attack, stroke and lung disease.

Longevity isn't about discovering enough positive interventions to compensate for major negative ones. Sometimes the highest-return decision is simply removing a large risk.

5. Protect your sleep

Sleep is easy to sacrifice because it doesn't feel productive. But your body doesn't agree. Sleep supports physical recovery, cognitive function, mood and overall health. The National Institute on Aging recommends making sufficient, good-quality sleep part of a healthy ageing strategy.

Rather than obsessing over a perfect sleep score, focus on the basics:

• enough time in bed
• a reasonably consistent schedule
• a sleep environment that works for you
• addressing persistent sleep problems rather than simply accepting them

A longevity strategy that leaves you permanently exhausted isn't much of a strategy.

For more info, start with Sleep: The foundation everything else is built on

6. Know your numbers

Healthy ageing isn't just about what you do, it's also about knowing what's happening inside your body. Blood pressure. Cholesterol. Blood glucose. Body composition. Fitness. Other appropriate health measures and screening.

The exact measurements that matter will depend on your age, circumstances and medical history. The point isn't to turn yourself into a walking spreadsheet, it's to identify meaningful risks early enough that you can do something about them. Preventive healthcare exists for a reason.

If something concerns you, discuss it with an appropriately qualified healthcare professional rather than trying to diagnose yourself from an app or wearable.

For more info, start with Understanding Your Blood Tests: What the Numbers Mean for Your Longevity

7. Stay connected

Longevity is often presented as an individual optimisation problem. It isn't. Your relationships matter.

The National Institute on Aging notes that loneliness and social isolation are associated with higher risks of several health problems, including heart disease, depression and cognitive decline. Meaningful activities and social connection can support wellbeing and healthy ageing. That means your longevity plan should contain people: friends, family, community, colleagues, clubs, volunteering. Whatever gives you a reason to connect with other human beings.

A perfectly optimised body with nobody to share your life with isn't the definition of a great old age.

For more info, start with Mental Health & Relationships: The Harvard Study of Adult Development — What 80 Years of Research Tells Us About Living Well

8. Have something worth staying healthy for

This may be the most overlooked part of longevity. It's easy to become focused on adding years to life, but what are the years for? Travel? Family Learning? Sport? Work you enjoy? Helping other people? Creating something? Exploring? Playing? Being useful? Being curious? Having plans?

A healthy body gives you options, but you need something you actually want to use those options for.

The aim of healthy ageing isn't to spend your 90s measuring your biomarkers. It's to spend them living.

9. Don't confuse longevity with optimisation

You don't need to track everything.

You don't need the newest wearable.

You don't need twenty supplements.

You don't need to eliminate every possible risk from your life.

And you certainly don't need to spend every waking hour trying to extend your lifespan.

There is a point at which optimisation becomes counterproductive. The fundamentals matter because they're sustainable. Exercise. Eat well. Sleep. Don't smoke. Limit alcohol. Maintain strength. Stay connected. Know your health risks. Keep learning.

Enjoy your life. Then repeat. For decades.

10. Think in decades, not days

This may be the most important longevity habit of all.

Your health at 80 isn't determined by what you do on one Tuesday when you're 59 — it's shaped by thousands of decisions made over many years. That's both daunting and empowering. A bad week doesn't ruin your future, and one excellent week doesn't transform it. What matters more is the direction of travel.

If you're 45, think about the person you want to be at 60.

If you're 60, think about the person you want to be at 75.

If you're 75, think about how you want to experience your 80s and 90s.

Then work backwards. What capabilities will that person need? Cardiovascular fitness. Strength. Mobility. Cognitive function. Social connection. Financial security. Purpose.

The earlier you start building them, the more time they have to compound.

The goal isn't simply to live to 100

There is an important distinction between lifespan and healthspan.

Lifespan is how long you live.

Healthspan is how long you remain healthy and capable.

You can't control your lifespan completely. Genetics, environment, chance, medical events and circumstances all play a role. But you can influence some of the factors associated with your health trajectory. And that changes the question.

Instead of asking: "How do I guarantee that I'll live to 100?" ask: "What can I do today to improve my chances of reaching old age in good health?"

That is a question with useful answers.

Then there's the other half: Wealthspan

There is one more thing that becomes increasingly important as we succeed at living longer.

Money.

If you're fortunate enough to remain healthy and active into your 80s and 90s, you need financial resources that can support those years. That's where Wealthspan comes in.

Your Wealthspan is the period for which your financial resources can support the life you want.

Your Healthspan and Wealthspan are different things, but they are deeply connected. You might have excellent health but insufficient financial resources to enjoy your later years. Or you might have more than enough money but spend your later decades unable to do the things you had planned.

The ideal isn't simply a long life — it's a long life in which health and financial freedom overlap.

For more on the financial side of longevity, read How Much Money Do You Need to Live to 100?.

For the broader framework, read What Is Longevity Financial Planning?.

Build the years you want to live

Nobody knows exactly how long they will live, but that uncertainty isn't a reason to ignore the future. It's a reason to prepare for more than one possible future.

Build your cardiovascular fitness.

Maintain your strength.

Eat well.

Protect your sleep.

Avoid major health risks.

Stay connected.

Have something to look forward to.

Know your numbers.

And make sure your finances are strong enough to support the life you want if you're fortunate enough to live for many decades.

The goal isn't to become obsessed with reaching 100 — it's to make 100 a possibility worth planning for.

Live longer. Stay capable for longer. And make sure you have the freedom to enjoy the years you get.

That's the idea behind 100 Great Years.

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This article is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional before making decisions about your health.