HIIT (what is the right speed and time?)

[skully]

Honestly I am so confused. I hear a lot of different things.

What are the speeds to be used in HIIT to make it really work?

Long time ago I used to do this:

1 minute and a half walking at 4.5 km/h
15-30 sec sprint at 11-16 km/h

I found that a bit too much for me as I am not YET very physically capable, and I always get a lot of pain in ribs and sides area from jogging/running fast.

So What I do now is occasionally I would walk at 5 km/h, and run between 7-9 km/h, depending how I feel at the moment and if I'm up to challenging myself, and IF I am not in pain.

I'd usually go about it for 15-20 minutes.

A few weeks ago, I couldn't handle doing 6 minutes of this. Today I did 15mins!

So what is right??

[fitoverforty]

What are the speeds to be used in HIIT to make it really work?

It all depends on your fitness level.

Long time ago I used to do this:
1 minute and a half walking at 4.5 km/h
15-30 sec sprint at 11-16 km/h

What you did a long time ago may not be what you can do at this time.

So What I do now is occasionally I would walk at 5 km/h, and run between 7-9 km/h, depending how I feel at the moment and if I'm up to challenging myself

HIIT is all about challenging yourself, that is the basis of it. You should be doing your fast sprints at a level that is something that you cannot sustain for more than 30 seconds or so. Then your slow time should be long enough (usually 1 to 2 min.) to recover, but not fully - you want to keep your body working throughout the session. Repeat the cycle of slow/fast at least 3 times and as you improve you can add more cycles, and increase your speed on the fast part.

A few weeks ago, I couldn't handle doing 6 minutes of this. Today I did 15mins!

That sounds to me like you are ready to increase either your speed or increase your intervals - but that is a good thing! It shows you are becoming more conditioned and fit.

[skully]

What are the speeds to be used in HIIT to make it really work?

It all depends on your fitness level.

Long time ago I used to do this:
1 minute and a half walking at 4.5 km/h
15-30 sec sprint at 11-16 km/h

What you did a long time ago may not be what you can do at this time.

So What I do now is occasionally I would walk at 5 km/h, and run between 7-9 km/h, depending how I feel at the moment and if I'm up to challenging myself

HIIT is all about challenging yourself, that is the basis of it. You should be doing your fast sprints at a level that is something that you cannot sustain for more than 30 seconds or so. Then your slow time should be long enough (usually 1 to 2 min.) to recover, but not fully - you want to keep your body working throughout the session. Repeat the cycle of slow/fast at least 3 times and as you improve you can add more cycles, and increase your speed on the fast part.

A few weeks ago, I couldn't handle doing 6 minutes of this. Today I did 15mins!

That sounds to me like you are ready to increase either your speed or increase your intervals - but that is a good thing! It shows you are becoming more conditioned and fit.

thanks for telling me so! I always find it confusing to figure out what's the right thing to do for HIIT. I'll try doing 5, 8km/h...and work way to higher and higer...with 8 and 9, i can run for 45sec..so if I increase speed every week/session, I will be able to run at 11 km/h in a few weeks time, for 30 secs...