Not necessarily true, especially if we're talking HIIT. While it may increase the rate of fat loss initially, if her resistance program is good, it should have some lower body work in it. Doing that, then HIIT the next day, then RT again, then HIIT again, then RT...it's a recipe for stalled progress down the track as the legs don't recover from either session before being worked again, so training can't improve. Furthermore (and this is much more important to me), it's a setup for overuse injuries, which would definitely stall progress.
Steady State HR, by nature, is low-to-moderate intensity, because higher intensity would not be maintainable for long, so 1-2 SS sessions per week would probably be more beneficial than HIIT. At a low intensity it should improve recovery from the day before, and at a moderate intensity (about 60%MHR) it should have some improved health benefits without impairing progress.
I do some HIIT here and there, so I'm not too worried about it becoming a problem. I usually get 2-3 days (usually just 2 days) of FBW which includes squats, lunges, side lunges, rows, flies, pushups, presses, planks, etc. and I run or hike 2-3 days a week (again, usually just 2 days) for about 30 minutes or so--just recently ran 10k for the first time-- and then I play a 2 hour game of soccer on Sundays, and every other Sunday is a 3 hour hike in the mountains with the hiking club here. Sometimes I can still make the soccer game after hiking if the hike wasn't too long. So, I can say I get 4-6 days of workouts a week of either FBW or cardio.
HIIT: Since I was told that HIIT should make me feel like death, I know that doing a FBWO the following day would be silly since my muscles went through enough on the HIIT day. I've tried Tabata sprints and really loved/hated them, but have only kept that for every once in a while. As part of my plan, if I do Tabata sprints or any other HIIT, I usually use them in place of a FBW. But I have a question about HIIT then: does it really increase the rate of fatloss? I've heard conflicting thoughts on this. I remember trying to make sure I had HIIT 1-2 times a weeks when I first started out, but have not really kept up on it. I laugh when I say I count my soccer day as HIIT since I'm sprinting up and down a bit, but all in all, it isn't hard enough to call it HIIT and I'm able to sustain the 2hr game (hence, still cardio!) It may be considered MIIT, but nonetheless, it is still just an extra day of exercise for me since I enjoy it so much and don't consider it a requirement of my exercise program.
Diet: I'd say my diet is good. Not great and totally clean, just good. We live in Korea for the time being and so luckily, processed crap is not east to find. I cook 95% of our meals, and I have a toddler whom I wish to keep on a healthy diet, so we eat well balanced meals. I cannot deny, however, that I do eat out with my friends and make not so great choices (the Indian restaurant here is hard to resist, and I do indulge in Starbucks coffees more than I should), but I'm still losing weight so I know Im ok for now until I get closer and closer to my goal weight where I might have to start watching every single calorie.
Oh, since we're moving back to the USA in 1 month, I know that the transition through hotels and such means a very high chance of derailing my diet and exercise routine, but we're gonna do what we can. When we visited for Thanksgiving, we joined a gym for 2 weeks, so we might do that while we find a place to live and settle in. Moreso, I'd say it's the meeting up with family and friends that makes it extremely difficult time-wise.
And Buzz, what is CNS?