Does Training Harder Make You Live Longer?

Exercise really is associated with a longer life

One of the largest analyses to look at physical activity and life expectancy combined data from 654,827 adults. Compared with doing no leisure-time physical activity, even relatively small amounts of exercise were associated with longer life expectancy.

One of the most striking findings was that doing the equivalent of brisk walking for up to 75 minutes per week was associated with about 1.8 additional years of life expectancy after age 40 compared with being completely inactive — which works out to less than 11 minutes a day. People achieving roughly the recommended amount of physical activity or more were associated with gains of around 3.4 to 4.5 years, depending on their activity level.

The biggest jump might be from doing nothing to doing something

This may be the most important message in the whole article.

If you’re currently inactive, you probably don’t need to worry about the “perfect” amount of exercise. You need to start moving.

The relationship between exercise and health isn’t perfectly linear. The first bit of activity appears to buy you a surprisingly large amount of benefit, while additional exercise continues to help but generally with diminishing returns.

Think of it a little like money: if you have $0 in your bank account, receiving $1,000 makes a massive difference. If you already have $1 million, another $1,000 is still nice, just not life-changing. Exercise appears to behave in a similar way — going from nothing to something matters enormously, while going from something to more can still help but with gradually smaller returns.

That’s actually fantastic news, because it means you don’t need to train like an Olympian to get a substantial longevity benefit.

The famous Harvard alumni study

This brings us to one of the classic studies I discussed when I originally wrote this article.

Ralph Paffenbarger and colleagues followed 16,936 Harvard alumni, aged between 35 and 74, looking at their physical activity and mortality over 12 to 16 years. They found that death rates generally declined as weekly energy expenditure through walking, stair climbing and sport increased, with men expending around 2,000 kcal or more per week through physical activity having death rates roughly one-quarter to one-third lower than less active men.

This research helped establish an idea that seems obvious today but was enormously important at the time: physical activity wasn’t just something athletes did. It was associated with survival.

Paffenbarger’s work is also where the wonderfully catchy idea came from that every hour spent exercising might buy roughly two hours of additional life. I wouldn’t take that as a literal exchange rate — there isn’t a celestial accountant adding time to your expiry date every time you finish a workout — but the underlying idea was remarkably forward-thinking. Time spent exercising isn’t necessarily time “lost” from your life; it may be an investment in having more life to live.

So how much should we actually do?

Current guidelines give us a useful starting point.

The World Health Organization recommends adults accumulate around 150 to 300 minutes of moderate-intensity aerobic activity per week, or 75 to 150 minutes of vigorous activity, or some equivalent combination of the two. Adults are also advised to perform muscle-strengthening exercise involving the major muscle groups on at least two days per week.

That might sound like a lot, but 150 minutes works out to just over 21 minutes per day, and it doesn’t all need to happen in a gym. Brisk walking, cycling, swimming, sport, running, and structured training sessions all count.

The goal isn’t necessarily to become someone who “works out” constantly, but rather to become someone who moves regularly and trains their body enough to maintain its capacity.

But does doing more than the guidelines help?

This is where things get interesting.

For years there has been debate about whether there is an upper limit beyond which exercise stops providing longevity benefits, or perhaps even becomes harmful.

A large 2022 study followed 116,221 adults for up to 30 years and repeatedly measured their leisure-time physical activity. People performing roughly two to four times the recommended minimum amount of vigorous exercise had around a 21 to 23% lower risk of all-cause mortality compared with people reporting no long-term vigorous physical activity. For moderate activity, doing roughly two to four times the recommended amount was associated with about a 26 to 31% lower mortality risk.

Importantly, doing considerably more exercise wasn’t associated with a dramatic increase in mortality in this research, but the extra benefits did begin to level off. In other words, more can be better, but the return on every additional hour gets smaller.

That distinction matters, because it means you don’t have to spend your life training to extend your life.

What about training harder?

Now we get to the original question: does intensity matter? It appears that it can.

An Australian study involving more than 200,000 middle-aged and older adults found that people who included some vigorous activity had a lower risk of death than those whose moderate-to-vigorous activity contained no vigorous exercise. Among people who were already active, having less than 30% of their activity at vigorous intensity was associated with about a 9% lower mortality risk, while having 30% or more vigorous activity was associated with about a 13% lower risk, compared with doing no vigorous activity.

That’s interesting, but it doesn’t mean walking is useless or that everyone should start doing HIIT. Moderate activity is beneficial, walking is beneficial, and more daily movement is beneficial. The better interpretation is that once you have a good foundation of activity, occasionally turning up the intensity may provide some additional benefit.

What does “vigorous” actually mean?

This is where fitness language can become unnecessarily intimidating. Vigorous exercise doesn’t necessarily mean collapsing on the floor in a puddle of sweat while somebody shouts motivational slogans at you.

One common definition uses METs, or metabolic equivalents, where moderate activity is generally around 3 to 6 METs and vigorous activity is above approximately 6 METs.

In everyday terms, I prefer the talk test. During moderate exercise you’re breathing harder but can still speak in sentences; during vigorous exercise talking becomes noticeably more difficult and you can usually only manage a few words.

Running, fast cycling, hard rowing, swimming laps and interval training can all fall into this category — but intensity is personal. A brisk uphill walk might be vigorous for one person and easy for another.

Fitness may matter even more than exercise minutes

Here’s where the longevity story gets really interesting.

Instead of only asking how much exercise someone reports doing, researchers can measure cardiorespiratory fitness — how effectively your heart, lungs, blood vessels and muscles work together during exercise.

A 2024 overview of 26 systematic reviews representing more than 20.9 million observations across 199 cohort studies found that people with high cardiorespiratory fitness had substantially lower mortality risk than those with low fitness, with high fitness associated with roughly half the risk of all-cause mortality. Another large study of 122,007 people undergoing treadmill testing found that mortality progressively declined as fitness increased, with no clear upper threshold where the benefit suddenly reversed.

This shifts the question slightly. Instead of only asking “how many minutes did I exercise this week?” we might also ask, “am I maintaining or improving what my body is capable of doing?”

Your VO₂ max might be worth paying attention to

VO₂ max describes the maximum amount of oxygen your body can use during intense exercise. You don’t need to obsess over the exact number, and smartwatch estimates aren’t the same as laboratory testing, but the concept is useful.

A higher aerobic capacity means your cardiovascular system has more reserve when life demands it — climbing stairs, carrying luggage, walking uphill, running for a bus, playing sport, or keeping up with your grandchildren. The fitter you are, the smaller the percentage of your maximum capacity these everyday tasks require.

This is where training intensity becomes useful. Long, easy aerobic sessions build a base, but appropriately programmed harder efforts can be particularly effective at improving cardiorespiratory fitness. So yes, there is a good reason to occasionally get out of breath.

And then there is strength training

The original version of this article focused heavily on jogging and aerobic exercise, because that’s where much of the classic longevity research began. Today, we know the story is bigger than that. Strength matters too.

A systematic review and meta-analysis found that doing any muscle-strengthening activity was associated with around a 15% lower risk of all-cause mortality compared with doing none. More recent long-term research involving 147,374 people followed for up to 30 years found that around 90 to 119 minutes of resistance training per week was associated with a 13% lower risk of all-cause mortality compared with none, especially when combined with aerobic exercise.

That combination makes enormous sense: your heart, lungs and muscles all need training, especially as you get older — because longevity isn’t only about remaining alive. It’s about remaining capable.

Living longer is great. Living better is the real prize.

This is the part that sometimes gets lost when we talk about longevity.

Imagine being guaranteed another five years of life. You’d probably take them. But what matters more is what those years look like: being able to travel, walk around a new city, play sport, get up and down from the floor, carry your shopping, look after your garden, play with your grandchildren, and live independently.

Suddenly we’re no longer talking purely about lifespan, but about healthspan — the portion of life spent in good health and function. This is why strength, balance, aerobic fitness and everyday movement all belong in the conversation.

What about steps?

You knew they were going to sneak into the conversation eventually.

For years, 10,000 steps per day has been treated almost like a biological law, but it wasn’t originally based on human physiology. The evidence now shows a more nuanced picture.

A major 2022 meta-analysis found that mortality risk declined as daily steps increased, but the relationship eventually flattened. For adults aged 60 and over, much of the benefit occurred by around 6,000 to 8,000 steps per day, while for younger adults the curve levelled at roughly 8,000 to 10,000 steps. A 2025 systematic review also found that around 7,000 steps per day, compared with 2,000, was associated with a 47% lower risk of all-cause mortality.

The lesson isn’t to chase a new magic number, but to recognise that every increase from a low baseline matters. If you’re averaging 3,000 steps, aim for 4,000, then 5,000. Your body doesn’t stop benefiting just because your watch didn’t celebrate 10,000.

So should everyone start training harder?

No.

Hard training is a tool, not a requirement for every session. If you’re currently inactive, returning after time away, managing an injury, or living with a medical condition, jumping straight into high-intensity exercise isn’t necessary or wise. Build your foundation first: walk, move, develop strength, learn good technique, and gradually improve your aerobic capacity before introducing harder efforts.

There’s a big difference between challenging your body and punishing it. Good training applies enough stress to stimulate adaptation and then allows recovery so that adaptation can actually occur.

Is there such a thing as too much exercise?

Of course. Very high training volumes can increase the risk of overuse injuries, fatigue, and other issues, especially when load increases too quickly. At the extreme end of endurance sport, researchers continue to study potential long-term cardiac effects in some lifelong athletes.

But for most people, the far bigger issue is not doing too much exercise, but too little. We’re sitting too much, losing fitness, losing muscle, and not regularly challenging our bodies.

What a good longevity plan actually looks like

If I were building a routine for long-term health, I wouldn’t chase one perfect workout. I’d aim for a mix:

• Plenty of low-to-moderate movement, like walking
• Regular aerobic training that challenges the cardiovascular system
• Occasional vigorous efforts, where appropriate
• Strength training at least twice per week

You don’t need to do everything at once, and you certainly don’t need to train hard every day. What matters is that your week contains enough movement and enough challenge to maintain your body’s capacity.

So, does training harder make you live longer?

Possibly — but that’s not quite the right conclusion.

The strongest message from the research isn’t that everyone needs to train harder. It’s that being physically active is far better than being inactive, that more activity generally provides additional benefits, that maintaining high cardiorespiratory fitness is particularly powerful, and that combining aerobic exercise with strength training gives you an excellent foundation for long-term health.

You don’t need killer workouts, marathon training, or hours in the gym. You need to keep moving, occasionally challenge yourself, maintain your strength, and give your cardiovascular system something meaningful to do.

And the best part is that you don’t have to wait decades to benefit. Exercise improves your life today: you become stronger, more capable, more energetic, and more resilient. If it also gives you a few extra years to enjoy that, that’s a pretty good return on investment.