Why are cardio minutes doubled Versa 2

[wicked_sticky]

I found the FB article explaining that 

1 cardio minutes counts as 2 zone min.  (& 1 fat burn min = 1 zone min)

Why?
What  benefit to see it that way? 

AFAIK you need 25min cardio a day, a 50min slow walk doesn't do the same thing for your heart as 25min run (or does it?)

[MarkMM]

@wicked_sticky "AFAIK you need 25min cardio a day, a 50min slow walk doesn't do the same thing for your heart as 25min run (or does it?)"

That's exactly the point. If you walk slow (but at least fast enough to be in fat burn zone), for 50 minutes, you get 50 zone minutes. If you run 25 minutes and are in cardio or peak zone, you'll get 50 zones minutes as well. Think it's a motivation thing. Trying to motivate people to work harder. I've been shooting for 2000 zone minutes a week since it started, and get the weekly recommended 150 Every Sunday.

Not sure you need 25 minutes cardio a day? Last I saw, 20 minutes three times a week was the recommended minimum? Although I do more than that, I don't think it's a universal need. 

[wicked_sticky]

might be motivational but not usful  ie I walked 5miles out (plan was to go casually for fat burn, then jog  to get 40min cardio, walk the rest of the return 5, The walk took 170 min \and the fb read 338 active zone min, <Not helpful