I've been doing cardio first thing in the morning, and immediately after work. Basically 30 mins of HIIT counting warm up and cool down time. My question is this, should I do cardio twice a day, even on weight training days or should I just limit it to once a day on wieght days?

personal opinion is you should limit it to once a day, take a day off and do weight training, then do another day of cardio. the last thing you want to do is overtrain bro! my schedule looks like this ::

mon - lift
tues - cardio
wed - lift
thurs - cardio
fri - lift
sat - cardio later in morning
sun - rest and relax day

this week i reversed my cardio and lift days just to switch it up a bit.

Cardio is most effective for burning fat when you do it first thing in the morning. If you are getting 30 minutes every morning I think that is more than enough. If you really enjoy it then by all means do more, but don't push yourself to the point where it is not fun or you are getting injured. Personally I only do cardio 3 to 4 days a week, and weight training 3 times (opposite days). and that seems to work OK for me.

Out of curiousity, how long it your HIIT session sans the warm up/cool down?

And just for the sake of comparison, I do 45 minutes of mid-range cardio on my lifting days (Monday, Tuesday, Thursday, Friday). On my non-lifting days, I do 17 minutes of HIIT on the treadmill (that is NOT including warm up/cool down).

Out of curiousity, how long it your HIIT session sans the warm up/cool down?

And just for the sake of comparison, I do 45 minutes of mid-range cardio on my lifting days (Monday, Tuesday, Thursday, Friday). On my non-lifting days, I do 17 minutes of HIIT on the treadmill (that is NOT including warm up/cool down).
on my lifting days, i only do 6 to 10 minutes of cardio to get the blood flowing, because i hit my legs hard at the beginning of my routine. i do squats, then lunges, then deadlifts. if i did anything longer than 10 minutes, i dont think id have the energy to kick butt in the leg portion of my routine.

on my cardio only days, i do 21 minutes of HIIT, 2 minutes warmup, 1 to 2 minutes cooldown.

I can understand where you're coming from.

When I first switched to ass-to-grass squats and started my cardio regimen (7 days a week) I was worried about my cardio on leg day (which is, on any lifting day, 45 minutes about 8 hours following my lifting) and the day after leg day (which is 17 minutes of HIIT). However, I decided to suck it up and get on the treadmill and, much to my surprise, the cardio largely negates the soreness from working legs (that is, while you're doing the cardio). I know DOMS are different for everybody, so I can certainly appreciate your decision, but for me I can do cardio every day of the week, despite my heavy leg days.

...And that doesn't mean I like cardio. No sir. :)

but i thought EVERYONE loved cardio!!! i tell ya what, i read a bunch of stories about people getting sick after doing legs very heavy, or even vomitting. i thought it was a joke... until i did legs very heavy, and nearly lost my whey shake walking to the incline bench. gotta love that! its happened nearly every now, i guess because of the intensity, focus, etc. i cant wait till next month, when my routine turns into a two-day split, and my leg routine is just that, a separate leg routine. airsickness bag anyone!?!?!

Heh, I've almost puked a few times. I used to do squats, stiff leg deadlifts, and leg press on the same day, along with standing and seated calf raises. That was simply brutal (and, might I add, overtraining: three pyramind sets of each, except for squats and leg presses which were 5 sets each).

Recently I was doing squats and SLDL's along with lying leg curls and standing calf raises and that would make me feel puktastic if I didn't rest enough in between sets.

Now that I got rid of SLDL's and put in their place Dumbell Lunges (which are brutal, in a good way) and added seated calf raises back in, I have yet to feel sick at all. I can't explain it, but then again, my weight has continued to go up for each exercise on a weekly basis (this is while cutting) and I've even added size to my thighs and calves.

Just goes to show that whether it's cardio or lifting, everybody's different. Whatever works for you, do it.

I've been doing cardio first thing in the morning, and immediately after work. Basically 30 mins of HIIT counting warm up and cool down time. My question is this, should I do cardio twice a day, even on weight training days or should I just limit it to once a day on wieght days?

If you're trying to loose weight, alot of cardio will help. If you're trying to put some muscle on then you should consider doing less.

If you're trying to loose weight, alot of cardio will help. If you're trying to put some muscle on then you should consider doing less.

I also heard that leg workouts are great for losing weight. Basically, your legs consist of a good portion of your body's total muscle mass. The stronger you make them, the more calories you burn. Stronger legs should also improve performance w/ your cardio.

I also heard that leg workouts are great for losing weight. Basically, your legs consist of a good portion of your body's total muscle mass. The stronger you make them, the more calories you burn. Stronger legs should also improve performance w/ your cardio.

It is true for the whle body. The more muscle you have in the body the more calories you burn during the day. The thing is that fat is not coming of one body part. It gradualy comes off the whole body: a little by little.