I am new to Peloton. I am fit (thought I was) yet I cannot reach the output that the trainer(s) say in the class. Either I cannot go the same resistance OR if in that resistance, I cannot achieve the Cadence. Please tell me what I am doing wrong? I do not want to build - I want to tone down and loose weight (as recently i have picked up weight on my top leg/bum area). I like the HIIT and the diversity. But why can I not get anywhere near the output that they are suggesting?