Many people wait until later life to “get serious” about exercise — often after a health scare or a new ache that won’t quite go away.

But compelling new research suggests the real foundation for a longer, healthier life is built much earlier.

What you do in your 40s and 50s could have a bigger impact on how long you live than anything you start later on.

The Study That Redefined Midlife Fitness

A large international review published in the British Journal of Sports Medicine in 2025 found that adults who stayed active throughout adulthood had up to a 40% lower risk of early death than those who remained inactive.¹

Researchers analysed decades of data from 85 studies, following thousands of adults across several continents. They compared lifelong exercisers, those who became active later in life, those who stopped, and those who were consistently inactive.

The findings were clear:

• Staying active across adulthood reduced the risk of early death by around 40%.

• People who started exercising later in life still lowered their risk by roughly 22%.

• Those who stopped moving lost most of the benefit.

In other words, it’s consistency that counts — not intensity, not perfection, and not the occasional burst of motivation.

Why Your 40s Are So Crucial

Midlife is often when work, stress, and family take priority — and activity quietly slips away.

But this is precisely when your body begins to change in ways that make exercise more protective than ever.

• Muscle loss begins in your 30s. Staying active slows this decline, preserving metabolism and strength.

• Heart health starts to shift. Arteries gradually stiffen, blood pressure rises, and cholesterol can creep up. Regular activity keeps vessels flexible and blood pressure stable.

• Hormones fluctuate. In women, perimenopause can bring fatigue and weight gain; in men, testosterone begins to decline. Exercise helps regulate hormones and mood.

• Inflammation increases. Low-grade inflammation — sometimes called “inflamm-ageing” — builds silently. Physical activity keeps it in check.

• Brain benefits. Large UK Biobank studies show those who stay fit in midlife are less likely to experience cognitive decline decades later.

Think of movement as a long-term investment: what you put in during your 40s pays dividends in your 70s and beyond.

The Longevity Equation: Consistency, Intensity and Timing

Research points to three interlocking principles for a longer, healthier life:

• Consistency — Regular movement over months and years matters more than brief bursts of effort.¹

• Intensity — Moderate exercise such as brisk walking, cycling or swimming delivers most of the benefit.²

• Timing — Starting in mid-life provides a longer protective runway, though gains appear at any age.¹

And just as important: recovery. Rest days, sleep and stretching allow muscles and joints to repair, preventing overuse injuries.

Movement should challenge your body — not exhaust it. Sustainable activity, balanced intensity, and regular rest together form the real longevity equation

According to NHS guidance, adults should aim for at least 150 minutes of moderate activity (or 75 minutes of vigorous activity) weekly, plus muscle-strengthening exercises on two or more days.³ The goal isn’t endless effort — it’s steady, balanced movement that lasts a lifetime.

Small Steps, Big Results

Recent studies show how even modest amounts of daily movement can make a measurable difference.

• A 2023 meta-analysis covering more than 220,000 people found that just 3,967 steps a day was associated with lower overall death risk — and benefits increased with each extra 1,000 steps.²

• A 2025 JAMA study reported that adults walking for 100 minutes a day had a 23% lower risk of developing chronic lower-back pain than less active peers.⁴

• Another JAMA analysis found that simply walking 8,000 steps on three days a week was enough to cut early death risk.⁵

The message? You don’t need to train for a marathon — consistency and everyday movement count more than you might think.

Practical Ways to Stay Active in Your 40s

• Break up sitting time: Every hour, stand and stretch or walk for a couple of minutes.

• Build movement into your day: Walk or cycle to the shops, use stairs, or park further away.

• Protect your joints: Try swimming, yoga, Pilates or low-impact aerobics.

• Add strength work: Body-weight exercises or light weights twice a week keep muscles and bones strong.

• Make it enjoyable: Find something you actually look forward to — dancing, gardening, group walks — enjoyment is key to long-term consistency.

• Set realistic goals: Track steps, minutes or classes attended — small wins build momentum.

If You’re Starting Late — Especially Over 50

If your 40s were spent behind a desk, don’t worry. The science is clear: it’s never too late to benefit.

The BJSM analysis showed that people who went from inactive to active in adulthood still cut their risk of early death by more than 20%.¹

Even short bursts of movement matter — one US study found that a 15-minute brisk walk each day was linked with nearly 20% lower mortality in adults from diverse backgrounds.⁸

Starting later isn’t a disadvantage — it’s an opportunity. In fact, older adults often see faster gains in energy, mobility and mood once they get moving.

Here’s how to start safely:

• Begin with low-impact activities like walking, swimming or cycling.

• Gradually increase time rather than speed.

• Include gentle strength exercises to support balance and bone health.

• Involve friends or family — shared goals make it easier to stay motivated.

• Check with your GP before starting if you have any chronic conditions.

Each step you take today literally adds to your future — not just in years, but in quality of life.

The bottom line

Your 40s may be the most powerful decade for shaping how long — and how well — you live.

But it’s not a race or a test of fitness; it’s a lifelong relationship with movement.

Stay consistent, keep it enjoyable, and remember: the best time to start was yesterday — the next best time is today.