kheegster wrote:While I can see the benefit of combining high intensity during resistance workout if one is pressed for time, for people who have enough time to do separate resistance and interval sessions this seems to make more sense.
Well intervals certainly add a cardiovascular aspect to your weightlifting, so you can more out of it in that sense. And that's especially important if you aren't doing a lot else for cardio. If you don't care about cardio at all, then perhaps it doesn't matter.
As bird said, you keep trying to improve your workload through more weight and/or more sets. You do the weight / rest time / sets at the rate that you need to while not losing form. Then improve from there.
What's the benefit if you're already doing cardio? Well at very worst you'll look like a badass dripping sweat and huffin and puffing around the gym going nonstop while all the schmoes are sitting on their bench doing arm curls every few minutes
But there is other benefit. Let's back up a second. To get greatest conditioning you want to workout intensely - which quite likely means you will need some days of rest as well. Let's say you got 4 days a week to do resistance / cardio. How would you break it up? How many days would you spend lifting weights? Would you do cardio and weights on the same days?
If work the whole body in a single workout with weights (twice a week), then that leaves you other days to do cardio. If you were taking your time in between sets, you'd need a loooong time to do that whole body workout.
Or you could chose to do some muscles on different days, and mix in cardio on each day. However, this likely will be less beneficial from a hypertrophy / strength gain standpoint.
Producing large forces is the most important element in strength / hypertrophy, so you do want to have some rest between sets of a same muscle. What I do is sort of mini circuits, say of 3 different exercises and cycle sets. This way I'm constantly doing something, but give each exercise a few mins rest. This works very well.
With decent nutrition, you can easily get out what you want in 2 days. That leaves other days for intense cardio training / stretching / sleeping in.