How intense is HIIT suppose to be?

[AC-DC]

Hey, i've just started cardio and heard that hiit was the best fat burning cardio.

I use the treadmill, and was just wondering how intense the sprint intervals are suppose to be? I saw some videos on youtube on HIIT, but at the intense parts they were only running, not really sprinting.

How is it suppose to be done? Thanks

[AC-DC]

well i did 10miles an hour on the treadmill for my intense minute, and 4 miles for my rest minute. Is this the kind of intensity i should be at?

[JuiceWeasel]

i would just go as intense as i can possible go, thats the idea. Start your intense periods at 45seconds and rest at a minuet and add 5 seconds onto your intense periods each time untill you have done 20-25mins. So....

5min warmup
45 intense
60 rest
50 intense
60 rest
55 intense
60 rest
60 intense
60 rest
55 intense
60 rest
50 intense
60 rest
45 intense

Obviously there are many variations of what times you can use.

[AC-DC]

i would just go as intense as i can possible go, thats the idea. Start your intense periods at 45seconds and rest at a minuet and add 5 seconds onto your intense periods each time untill you have done 20-25mins. So....

5min warmup
45 intense
60 rest
50 intense
60 rest
55 intense
60 rest
60 intense
60 rest
55 intense
60 rest
50 intense
60 rest
45 intense

Obviously there are many variations of what times you can use.

What speed on the treadmill do you do for the intense periods?

[LankedOut]

I've done 20 seconds flat out, then 1 minute 40 seconds rest x 12 with a 2 minute warm up at the start and 2 minute warm down at the end on a spin bike. Came to within an inch of throwing up everywhere.