The zone zero secret: how ultra-low-stress exercise can change your life

The Guardian

2 days ago

In our modern, time-squeezed lives, it's tempting to do everything as fast as possible: listen to podcasts on double speed, work in email-free sprints, or train at lung-bursting intensity in the gaps between your morning meditation and the school run. But evidence is piling up that the last one might not be as beneficial as it seems – and that, in fact, just introducing a lot more ultra-low-intensity movement into your schedule can improve your fitness as well as your quality of life, whether you're a top-tier athlete or experienced couch-crasher. Welcome to zone zero.
In case you're unfamiliar with the concept, or just need a quick refresher, zone training is a way of structuring workouts based on how high your heart rate gets as a percentage of the fastest it can possibly thump. Lower means slower – and most of us will never hit maximum intensity in our day-to-day lives. Over the decades, the most-recommended zones have shifted as training techniques evolve and knowledge of our biology improves – but zone zero, the state just slightly above total inactivity, where your heart never gets above 50% of its maximum rate, is enjoying a resurgence.
One reason? It's easy. Most zone training requires you to know your maximum heart rate – the British Heart Foundation recommends deducting your age from 220, though more accurate, less pleasant methods exist – and then making sure it doesn't go too high or low, usually by training with a heart rate monitor. Zone zero, though, doesn't require any of this. It's essentially where you spend most of your semi-active life: walking slowly, doing light tidying, or even working at a standing desk. It shouldn't really feel like exercise at all – but it might help you live longer, run faster, or feel better.
'Zone zero is an accessible way to increase daily movement without the need for formal workouts or special equipment,' says Brian Passenti, founder of Altitude Endurance Coaching. 'Getting more time in it can be as simple as parking further from the shops to get more steps in, taking a walk break while on a work call, or standing and stretching regularly at your desk. Of course, as you get more used to it, you can walk further or more frequently throughout your day, until you're spending hours in zone zero rather than on the couch.'
To understand why this is beneficial, it helps to know a bit about how your body fuels itself. After a meal or snack, carbohydrates are broken down and released into the bloodstream as glucose (a form of sugar), with any excess stored in the liver and muscles as glycogen. When you stand up or walk around, your muscles start contracting, which uses some of this glucose for fuel. This can have dramatic effects over time – a 2022 review of studies found that even a little bit of light-intensity walking was enough to 'significantly attenuate' post-food glucose levels compared with continued sitting, which almost certainly reduces your risk of insulin resistance and type 2 diabetes. Although there's some criticism of the idea that people living in 'blue zones' (those regions of the world where life-and-health span might be slightly longer than elsewhere) really differ from other populations, one thing that's fairly consistent among them is a significant amount of low-level activity, especially after meals – something that the evidence suggests is a pretty good idea.
Glucose is also released when you're stressed, as part of the body's fight-or-flight response – and managing that process might be one of the reasons that walking seems to be related to reduced stress, improved mood and general happiness. And there's another key element to the fuelling process – low-intensity exercise uses a higher percentage of fat for fuel than high-intensity exercise, which tends to rely on the quick energy hit provided by glucose. This means that walking for a long time, or walking in a fasted state (like taking the dog out before you have breakfast) tends to pull energy from your body's fat stores. Total calories burned matter, and so if fat loss is your main goal, adding more high-intensity exercise might get you there faster – but if that's unpleasant, injurious, or makes you ravenous, it may do more harm than good.
'For many of my clients – especially women in midlife or those just beginning their movement journey – zone zero is the bridge between sedentary and sustainable,' says Terry Tateossian, a personal trainer and nutritionist. 'It reduces stress, supports mental clarity, can help with improved circulation and better digestion, and it's a more enjoyable, flexible way to stick with training over time.'
It's also important to note that, in longevity terms, a bit (or a lot) more daily movement can play a huge role. A 2022 review of studies in the Lancet, for instance, found that taking more daily steps – fast or slow – was associated with a progressively lower risk of all-cause mortality, to an upper limit that varied by age. Another study led by the American Cancer Society found that any amount of walking, even at a moderate pace and at levels below the recommended guidelines, was associated with lower mortality risk. Consistency counts.
But what about more athletic endeavours? Well, even people who schedule workouts five or six days a week will still probably benefit from adding some extra low-intensity movement to their routine. A few more daily steps can bring all of the benefits mentioned above. But can going (very) slowly actually help you run faster?
This, it turns out, is a contentious area. Marathon data, for instance, shows that faster runners tend to spend a huge amount of time in the low-intensity zone compared with their slower peers – something that has prompted a recent examination in the European Journal of Applied Physiology. One theory is that faster athletes train a lot more in general – they're spending more hours on the roads and trails, and so some of those have to be slow so they don't burnout. This is the first of seven different hypotheses in the new piece, which notes that 'complete cardiac recovery from [high intensity] exercises might take over two days, limiting athletes to two to three weekly well-rested HI sessions' – leaving four or five days a week that can be filled with low intensity work.
There are also other explanations. Very low-intensity training may trigger training adaptations in a slightly different way to higher-intensity at the molecular level, or through different pathways. It might gradually remodel the structure and function of the heart (particularly the left ventricle), or shift the composition of an athlete's muscle fibres to the more endurance-focused (and economical) slow-twitch kind. It might also reinforce the effect of more serious training, as suggested by a 2021 study that found decreasing daily background steps actually blunted the effects of a high-intensity training programme.
'There have been studies comparing people doing training and getting 2,000 steps per day versus people doing the same training and doing 5,000 to 7,000 steps per day, and those getting more steps get better training adaptations,' says Brady Holmer, an exercise scientist and the author of VO2 Max Essentials. 'We often think it's best to do your training session and sit on the couch all day, but that doesn't appear to be the case. You need the high-intensity training to get a faster race time, but zone zero training plays a supportive role.'
It has been well established for some time now that 'active recovery' – even if you're barely doing anything – works to mitigate the effects of workouts that would otherwise leave you sore for days, by getting oxygen and nutrients to damaged muscle tissue through better blood flow. 'An easy walk around the block is the best way to combat sore muscles,' says Passenti. 'My wife is not as active as I am, but an easy after-dinner walk on a summer evening can offer benefits for both of us, and our dog too. While it may not directly improve sprint speed, it supports recovery and endurance development. Every bit of movement counts.'
But also, staying in zone zero is just … easy. High-intensity training is horrible almost by design: you might come to 'enjoy' it on some level, but it tends to have a negative effect on mood even in well-trained people. Going for a walk or a gentle yoga session, though, decreases mental fatigue and improves your mood, leaving you psychologically more prepared for the hard stuff.
'Zone zero addresses the biggest challenge I see across all levels of athletes: the inability to slow down,' says endurance coach Stephanie Holbrook. 'Over 16 years of coaching, I've found that most endurance athletes start out too hard and are simply not willing to embrace truly gentle movement. Zone zero – that sweet spot where you're just slightly active but not actually feeling like you're exerting yourself – can be revolutionary. For beginners who have never exercised, it removes the intimidation factor and shows that movement doesn't require suffering. For experienced 5k and marathon runners, it's often the missing piece that unlocks breakthrough performances because it facilitates genuine recovery without contributing to the body's stress response.'
So where to start? Anywhere you like. The point of zone zero is to stop thinking of your day as a split between workouts (horrible) and inactivity (non-ideal), and try to maximise the amount of very gentle movement you're doing without ever really worrying about it. In a typical day, that might mean going out for a quick walk before breakfast or getting off the bus to work a couple of stops early, getting up regularly for a stretch while you're at your desk, and going for a 20-minute wander at lunchtime. It could mean a short amble after dinner or a bit of very gentle yoga while you're watching Netflix (if you don't know any, just sit on the floor instead of the sofa, and you'll find yourself moving naturally). 'Start with 10 to 15 intentional minutes of zone zero a day,' says Tateossian. 'Add mobility while your coffee brews. Park further away on purpose. These micro-movements add up, and for people who feel intimidated by 'exercise', this is the entry point.'
It sounds like a hassle, compared with what many of us are used to – but if it pays off with improved mental energy now and a better quality of life later, it will be worth the effort. And, if you've never quite cracked the code to enjoying exercise, it could be just what you need. 'There can be a psychological breakthrough that comes from learning that sometimes the most powerful thing you can do is almost nothing at all,' says Holbrook. Besides, any form of exercise where you don't have to wash your gym kit has to be worth a try.
Zone 0: casual strollHeart rate: below 50% of max
Super-easy. Slow walking, gentle cleaning, or possibly just working at a standing desk. Spend as much time here as possible: it's where our hunter-gatherer ancestors would have spent most of their days.
Zone 1: getting goingHeart rate: 50% to 60% of max
Still barely challenging. This is where you'd be during an easy warm-up, walking the dog, or having a kickabout with a toddler. Useful for building work capacity for more challenging stuff.
Zone 2: this is fine
Heart rate: 60% to 70% of max
Easyish. You're breathing a bit harder, but you could still explain the plot of Severance if you really had to. Modern runners spend hours here to build a base without burning out. Can be boring, but very effective.
Zone 3: this isn't fine
Heart rate: 70% to 80% of max
This is where tempo runs – a pace that's right at the edge of your ability for sustained efforts – happen. You could talk, but you'd rather not. A zone that's fallen a bit out of fashion recently, as many coaches recommend a mix of long, slow training and higher-intensity efforts. Can still be useful, though.
Zone 4: can't talk, lungs hurting
Heart rate: 80% to 90% of max
Hard. This is what happens when you do intervals or threshold runs, or ill-advisedly sprint up an escalator as fast as you can. In theory, this is what nudges up your lactate threshold – or your body's ability to deal with lactate buildup in the blood. You can't sustain it for long, and you probably shouldn't try.
Zone 5: almost unbearable
Heart rate: 90% to 100% of max
Maximum effort: this is where you're redlining it because someone's yelling at you. Honestly, you probably don't need to be here much.