Hi,
I'm training HIIT in the mornings, 5 days a week.
The quesioin is about my training frequence
It's just that I do weightlifting in the evening, 4 times a week. I rest on the Wednesday. I'd like to know if I have to do HIIt in the morning and do it again in the afternoon, since i won't be doing weightlifting that day.

I'd like to know if I have to do HIIt in the morning and do it again in the afternoon, since i won't be doing weightlifting that day. You're already doing too much HIIT. Do it 2-3 times per week, 4 max. If you want to do more cardio, do steady state, lower intensity.

Also, the general advice is to seperate cardio & lifting days. If they can't be on seperate days, then make them at least 8 hours apart.

Thanks, what would u suggest to do in the weekends? rest?
and what happens if I do too much HIIT?

up!

Thanks, what would u suggest to do in the weekends? rest?
and what happens if I do too much HIIT?
Do steady-state, low/mod intensity cardio (65-75% MHR), as daveo suggested, on the weekend (or just Sat, and rest on Sun).

If you're doing HIIT 5 days a week, you run the risk of overtraining. You can do it, just make sure you're optimizing your rest, recovery, sleep, and diet to support your training frequency.