Is a 30-minute workout enough?

For most adults, yes. Thirty minutes is enough to count, enough to make a difference, and, more to the point, short enough that you'll actually do it. Here's how it adds up.

What the guidelines ask for

The World Health Organization's 2020 guidelines on physical activity suggest that adults aim for, every week:

• 150 to 300 minutes of moderate-intensity activity, or 75 to 150 minutes of vigorous activity, or a mix of the two; and
• muscle-strengthening activity on two or more days, working all the major muscle groups.

Five thirty-minute sessions is 150 minutes. That's the whole weekly target for moderate activity, at the low end of the range.

Moderate, vigorous, and why the difference matters

A common rule of thumb is the talk test. During moderate activity you can talk, but you couldn't sing. During vigorous activity you can only manage a few words before you need a breath.

The guidelines treat a minute of vigorous activity as worth roughly two of moderate. That's why a hard interval class punches above its length: two sessions of HIIT 30 cover about as much of your weekly target as four gentler ones.

It also means thirty minutes has to be thirty minutes of work, not thirty minutes in the room. A class helps here. The rests are timed for you, and nobody can pause to check their phone between sets.

Don't forget the strength days

Cardio gets most of the attention, but the strength part of the guidelines is just as specific: two days a week, all the major muscle groups.

Bodyweight is enough to start with. Squats, lunges, push-ups (from your knees is fine), bridges and rows cover the lot, and a backpack full of books makes them harder once they stop being hard. Strength 30 is built around exactly that.

A week of thirties

Here's one way to hit both targets with five classes:

Day	Class	What it counts towards
Monday	Strength 30	Strength day one
Tuesday	HIIT 30	Vigorous minutes
Wednesday	Low Impact 30	Moderate minutes
Thursday	Strength 30	Strength day two
Saturday	HIIT 30	Vigorous minutes

Add Stretch 30 on a rest day when you're stiff. It won't add much to the cardio tally, but it makes the other days feel better.

If five a week isn't happening yet

Then don't start with five. The same guidelines are clear that doing some activity is better than doing none, and that the benefits start well before you reach the target. Two classes a week is a perfectly good start. Three is better. In week one, the habit matters more than the number.

The 2020 guidelines also dropped the old advice that activity only counts in bouts of ten minutes or more. Every bit of movement adds up. Thirty minutes just happens to be long enough to do something properly, and short enough to fit in before work.

The honest caveat

Guidelines are about health, not about any particular goal. If you're training for a marathon, you'll need more than half an hour. But if the goal is to be fitter, stronger and less stiff than you are now, thirty minutes done regularly will get you there.

If you're injured, pregnant or have a medical condition, check with your doctor before starting a new exercise routine.

Source: Bull, F. C. et al. (2020). World Health Organization 2020 guidelines on physical activity and sedentary behaviour. British Journal of Sports Medicine, 54, 1451–1462.