Fewer adults take regular exercise than their parents' generation did.

Compared with their parents, adults today do much less physical activity. There are several reasons for this situation, and governments and individuals can take some steps to change it.

The first reason is the type of work. In the past many people worked in factories, in fields or in workshops, and they moved all day. Today most people sit in front of a computer for eight hours, so their body does almost nothing during the working day.

The second reason is transport. Before, people walked to the shop, to school and to work because they had no car. Now almost every family has a car, and many people drive even five hundred metres, so they lose all this natural movement.

A third reason is free time. After work people are tired, and it is much easier to watch a film at home than to go to the gym, especially in winter when it is dark and cold.

To change this, cities should build safe cycle paths and comfortable pavements so that people can walk or cycle to work without danger from cars. If the journey is safe and takes the same time, many people will choose it.

In addition, sport must be cheaper. A gym is very expensive for a family with a low salary, so governments should open free swimming pools and sport grounds in every district.

In conclusion, adults move less because their work and their transport changed, but safe cycle paths and cheap sport facilities can bring physical activity back into daily life.

Adults in most developed countries are considerably less active than the previous generation. The explanation is less about motivation than about what has been removed from ordinary daily life.

The principal cause is that movement used to be incidental. Earlier generations did not exercise more; they walked to work, carried shopping home, worked in jobs that required physical effort and had no alternative to any of it. Employment has since shifted overwhelmingly to seated work, so the eight hours that were once active are now sedentary by default.

Transport reinforces this. Car ownership and the way towns have been designed since have eliminated most short journeys on foot, and suburbs built around driving frequently have no continuous pavement or safe crossing at all. Longer commutes then consume the time that might have been used for anything else, and leisure has moved indoors towards screens, which are cheap, immediate and available in poor weather.

What follows is that promoting exercise as a leisure activity addresses the wrong thing. The effective response is to rebuild movement into journeys people already make: protected cycle lanes, continuous and well-lit pavements, and public transport that requires a walk at each end. This restores activity without asking anyone to find additional time, which is the resource most adults genuinely lack.

Accessibility matters alongside this. Gym membership is beyond many household budgets, and facilities are often concentrated in wealthier areas, so free or heavily subsidised pools, pitches and open spaces in every district would remove cost as a barrier.

In conclusion, adults are less active because physical effort has been engineered out of work and travel. Restoring it to daily journeys is more likely to succeed than urging people to take up exercise in time they do not have.

The premise deserves one correction before the question can be answered properly. The previous generation did not take more exercise; they took very little. What they did was move constantly without noticing — walking to work, standing all day, carrying things, cycling because there was no car. Activity was a by-product of ordinary life rather than an item on a schedule, and the decline being described is the disappearance of that by-product.

The first cause is the transformation of work. Employment has shifted from fields, factories and workshops to seated screen-based tasks, so eight hours that were once physically demanding are now sedentary by default. No individual chose this and no individual can reverse it from a desk.

The second is the design of the places people live. Car ownership eliminated short walking journeys, and development since has assumed the car — suburbs with no continuous pavement, retail parks unreachable on foot, and roads whose severance effect makes crossing genuinely dangerous. Walking did not become unpopular; in many places it became impractical. Longer commutes then consume precisely the discretionary hours that deliberate exercise would have to occupy, and screen-based leisure fills what remains because it is cheap, immediate and weatherproof.

Understanding this explains why decades of campaigns have achieved so little. They ask people to add a scheduled activity to a week that has less unallocated time than the previous generation's, and they address motivation when the binding constraints are time and infrastructure. Someone working nine hours and commuting two does not lack awareness of the benefits of exercise.

The effective response is therefore to restore movement to journeys already being made rather than to create new ones. Protected cycle lanes, continuous and lit pavements, safe crossings, and public transport that requires a walk at either end return activity to the day without requiring anyone to find additional hours. This is why cities that invested in cycling infrastructure saw participation rise across the whole population, including people who would never describe themselves as sporty — the behaviour changed because the environment did.

Cost and proximity complete the picture. Facilities are concentrated where incomes are highest and priced accordingly, so free pools, pitches and maintained open spaces in every district remove a barrier that falls hardest on the people whose health is worst. And workplaces can restore some incidental movement directly, through standing options and genuine breaks rather than through leaflets about wellbeing.

In short, activity was engineered out of ordinary life, and it will only return the same way — by being built back into what people already do rather than offered as something extra to fit in.