Which is best for weight loss?

I should say a shorter, more intense one is better. If you workout for too long, you burn more calories but at the same time you burn muscle which is not good. You said you're gaining muscle which is great & is the reason for your weight loss to slow down but that is OK. What matters more is how your clothes fit better & how good you look at the mirror or in pictures.

Definitely mix it up! Do 1 day high intensity interval training, then 1 day steady state, it's a great way to keep your body from adjusting and to keep you from getting plateaued! There are benefits to both styles. Just make sure your body has the proper fuel it needs for both workouts and that you have a post workout recovery snack with a 4:1 carb - protein ratio. This helps your body refuel for the next day and also keeps it from breaking down your own muscle protein. A low carb/sugar protein shake mixed with 1/4 cup raspberries is good...whey gourmet cookies & cream, kaizen vanilla or prolein are good ones:)

From a trainer: That would be me. Listen to your trainer. Hopefully your trainer completely understands your goals, your abilities, your strengths, and everything else, but you've got to tell her your concerns. Is she doing the same kind of workouts with all her clients? If she is, you need to find another trainer.

One thing I don't like to hear, is when people talk about just doing short intense workouts. Yes, you get a lot of bang for your buck, but there must be variety, and gosh once in a while exercise should be, dare I say it.....fun? Also, for all the people out there that try to tell me that cardio burns too much muscle and I'm wasting my time, I say "you haven't seen my legs, have you?" or my husband's who is an elite cyclist, racer and rides slow and fast up to 200 miles a week.

Endurance athletes usually mix it up, and we have plenty of muscle. Unfortunately we sometimes eat too much, which is why I'm on this website. Now that I have a way to track my calories and nutrients, I am timing my glycogen replacement and nutrtiton intake much better. Another thing you may or may not get to experience if you cut your workouts too short are endorphins. And endurance athletes know all about endorphins....Those wonderful little hormones that ADDICT you to exercise. And it takes a while, usually about 20 minutes for those to kick in. So I say, "don't worry so much about which kind." Tell your trainer your concerns. Make sure she understands what you're really willing to do, and she will hopefully come up with the right formula for you.

Google "interval training"

I think whats really best is one you'll stick to in the long run.

I totally agree with this...I would like to add a quote that a friend said recently "the best exercise is the one you aren't doing" meaning switch it up!