article via Facebook of all places! Amazing what slips through amid the pictures of angry looking cats and banal so-called "Only for geniuses" rubbish.
It's about a study done in Denmark looking at high intensity interval training that developed into a different routine. The researchers suggest a 30-20-10 approach where you do low intensity for 30 seconds, moderate for 20 and all out for 10 before resting and repeating. They call it 10-20-30, probably because that is easy to say and it scans nicely.
The results are interesting too, although there is a minor warning about injuries in the test group. Using runners the results showed an improvement in 5k times and a lowering of blood pressure plus other positive health markers. Interval training does improve endurance, so some of these affects are not a direct rest of the specific intervals used, but rather the impact of interval training in general.
The upside of the programme might lie in its simplicity. Some interval programmes can get quite complicated, so anything that makes it easy to do and easy to repeat is a good thing. If it makes it fun then all the better.