There’s a genuinely counterintuitive finding buried in physical activity research that’s worth taking seriously: hitting your weekly exercise target doesn’t fully cancel out the effects of sitting almost all day, every day, in between. The two are related but not interchangeable, which changes what “staying active” during a normal working day should actually look like.
The official guideline, and its limits
NHS guidance for adults aged 19 to 64 recommends at least 150 minutes of moderate-intensity activity a week (or 75 minutes of vigorous activity), spread across 4 to 5 days or more, alongside strengthening activities on at least two days a week. That’s a genuinely achievable target for most people. What the same guidance is explicit about, though, is a second and separate recommendation: reduce time spent sitting or lying down, treated as its own goal rather than something a good workout automatically fixes.
Why sitting time is tracked separately from exercise
The research behind this distinction is fairly intuitive once it’s spelled out: a 45-minute run is genuinely valuable, but it’s a small fraction of a day that might otherwise involve eight or nine hours sitting at a desk, plus a commute, plus an evening on the sofa. Long, unbroken periods of sitting have their own association with health risks — including cardiovascular risk — that isn’t simply undone by also meeting the weekly activity target. The practical implication is that “I exercised this morning” and “I’ve been sitting almost continuously since” can both be true on the same day, and the second one still matters.
What actually breaks up sitting time
NHS guidance on this is specific rather than vague: getting up and walking around for at least five minutes each working hour is the kind of concrete target that’s easy to actually act on, compared with a general instruction to “move more.” A few practical ways this tends to work in an ordinary office-based day:
Standing or walking for calls. Any call that doesn’t require a screen is a genuine opportunity to be on your feet or moving rather than seated.
Deliberately choosing the longer route. Taking the stairs instead of the lift, or walking to a colleague’s desk instead of messaging, adds up over a full week even though each instance feels trivial.
Structuring breaks around movement rather than just screens. A five-minute walk away from your desk does more for breaking up sedentary time than the same five minutes spent scrolling a phone while still seated.
Standing desks and walking meetings, where practical, directly address the “unbroken sitting” problem in a way that fitting in a gym session before or after work doesn’t.
Why this matters more for London-based desk work specifically
Commuting in London often already involves a reasonable amount of incidental walking — to and from stations, between platforms, the walk at either end of a journey — which is a genuine advantage over a purely car-based commute elsewhere. But that incidental movement is easy to overestimate as “enough,” when the actual guidance is about breaking up sitting throughout the working day itself, not just getting to and from it. A desk-based day bookended by a walking commute can still involve seven or eight hours of almost continuous sitting in between.
Strength, not just steps
It’s worth being specific that the guidance isn’t only about incidental movement — strengthening activity on at least two days a week, working the major muscle groups, is part of the same official recommendation, and tends to get less attention than step counts or cardio. For people newer to structured exercise, this doesn’t need to mean a gym membership; bodyweight exercises done at home cover the same “major muscle group” requirement the guidance actually asks for.
When to involve a professional
If you’re returning to activity after an injury, managing a chronic condition, or significantly increasing activity levels after a long period of inactivity, it’s worth a conversation with a GP or physiotherapist before making major changes, rather than relying on general guidance like this alone.
The practical bottom line
Meeting a weekly exercise target and reducing daily sitting time are genuinely two separate goals, not one that automatically covers the other. The more achievable win for most desk-based working days isn’t a longer workout — it’s making the existing day less continuously sedentary, five minutes at a time.
