What 60 minutes a day actually looks like.

The World Health Organization's Guidelines on Physical Activity and Sedentary Behaviour (2020) say that children and adolescents aged 5 to 17 should do an average of 60 minutes per day of moderate-to-vigorous physical activity, mostly aerobic, across the week. That's the number that matters.

Most parents read 60 minutes and picture a structured class. The WHO doesn't mean that. They mean the kind of breathing-too-fast-to-talk activity that comes from chasing a friend around a playground, riding a bike up a hill, or playing tag on a school field.

What "moderate-to-vigorous" actually feels like

The WHO defines moderate as activity that noticeably raises the heart rate and breathing, like brisk walking or active play. Vigorous is breathing too hard to hold a conversation, like running, swimming hard, or a soccer scrimmage.

A useful proxy: if your child can sing during the activity, it isn't moderate. If they can talk in short sentences, it is. If they can't talk, it is vigorous.

Why "60 minutes per day on average" is more forgiving than it sounds

The 2020 update to the WHO guidance changed the language from "every day" to "an average across the week". This matters. It means a Saturday in the woods can pay for a rainy Wednesday spent reading. It also means there is no single missed day that ruins anything.

That said: the average has to land at 60. Two strong outdoor afternoons a week and five sedentary ones do not.

The cost of not getting there

Multiple cohort studies have linked sub-WHO activity in childhood to higher BMI, worse cardiometabolic markers, lower bone-mineral density, higher rates of myopia, and worse academic outcomes (Tremblay et al., Applied Physiology, Nutrition, and Metabolism, 2016). The relationship is dose-dependent: more activity, better outcomes, and the steepest gains come at the bottom of the curve. Going from zero to 30 minutes a day matters more than going from 60 to 90.

How to count it without becoming weird about it

A few practical handles:

• A walk to and from school counts. So does the lunchtime playground.
• 30 minutes of a real outdoor game (tag, hide-and-seek, kick-about) almost always lands in moderate-to-vigorous.
• Cycling on flat ground at a kid's normal pace is usually moderate; cycling uphill is vigorous.
• "Standing around" at a park does not count, but most kids don't stand around for long.

This is why we built the streetlights rule into the structure of Outzy: an outdoor block of unsupervised play almost always blows past 60 minutes without a single timer. The phone-tracker-app approach to "screen-time minus active-time minutes" misses this entirely.

If you want a screen-time conversation that actually moves the needle, start with why the screen wins and then look at your week.