Gosh, I do think there's something to this. I used to do longer cardio sessions, 45 min. to an hour, and I'd usually follow it up with a 30 to 45 minute weight session and at times, my goal was to do this 4 to 6 times a week. Of course, long term I couldn't sustain this and eventually I'd abandon it. I'd be exhausted after exercising, and later on, ravenous as a result, so I think I ended up eating more because of all the exercise. I had a hard time believing you could get better results with shorter cardio, but I now think it's true. I've cut down to about 3 workouts per week, and I've cut my cardio down to 30 minutes max, sometimes only 20 minutes. I always incorporate HIIT into the cardio, and I think it works just as well if not better this way. I believe my results are better doing less. For one thing, I don't see any increased appetite from this kind of regime now. I've left the weights part of things the same, 30 to 45 minutes usually. The weights are my favorite.