Run a credibility check on your trainers credentials they may be made up considering the misinformation they are passing out.To train for 90 minutes to me means you are not following a proper programme, 30 to 40 minutes for a full body programme will get results and get them faster than a long drawn out workout doing multiple exercises for various body parts or muscle groups. The body is engineered to work best and respond faster to full body and compound movement exercises not multiple isolation exercises.
As Zorbs said, six exercises per session, challenge your muscles, work hard , get tired and go home to train another day.
It is called WORK-ing out for a reason.
I said getting fit was simple, I did not say it was easy.
Cardio burns calories, strength work burns fat.
Eat well to lose weight, exercise to get fit
You can not build a six pack using twelve packs
Often when we seek a magic bullet for fitness we end up shooting ourselves in the foot.
"I think calories are little germs in food that all moms are afraid of" Dennis the Menace