I'm sitting here with my morning joe reading an article in Scientific American about The Exercise Paradox. You can buy the February 2017 issue online and read it for yourself if you like. The author, Professor Herman Pontzer studies metabolism in humans and primates and his research shows that despite how much exercise a body does, cleaning the home vs running a marathon, the body still burns about 1900 per day for women and 2600 per day for men. He spent time with the Hadza tribe who lead a very active hunter gather life and compared their energy expenditure with far less active Europeans who are sedentary by comparison. Same energy expenditure.
Energy conservation is something our bodies do and rightfully so (no one gave it the memo about delicious ranch dressing, twinkies and cheese addiction). The body only will spend so much precious energy per day and when you're fueling it with more energy calories than it needs you can't offset them by getting up at 4 am to do 90 mins on the treadmill. This is why so many people don't lose or even gain when they exercise only and don't change much about their calorie intake.
While your trainer and fitbit/apple watch/other activity tracker may be lying to you in the calorie burn department the other documented benefits of exercise like muscle development (yes weight training works on building muscle), better sleep, stress management and cardiovascular health it's not going to help you lose any of those fat pounds.
I see all those elliptcals collecting dust now. What you put in your mouth is really all that matters in the battle of the bulge.
More info in the New York TImes Article. I'm just the messenger. I am gonna keep doing my outdoor fitness though. I Just love it.