I am learning the hard way, that honesty really is not the best policy when it comes to Personal Training. Of course, the whole point is to work hard, lose weight and get fit - right? That said, if you want to be pushed to your limit, be as honest as you like. If however you know your comfort zone and want to progress at a steady pace, then keep it zipped!
These are the phrases that I have uttered, unintentionally, and have been pushed to my max as a result. When I say to my max, I mean looking like I have been caught in a rain storm, spent too long on a hot beach, and generally having the appearance of someone who has had a few - dripping with sweat, blood red and wonky legged!! It really is not dignified!! You see if you say it's not too hard, it gets harder. If you are asked how you felt after your session and you say ok, it gets harder. If you are asked how that weight feels and you say ok, it gets heavier. You get the drift.
So, if you want to work hard, by all means use the following - but be warned!!
Me: I didn't find that too bad today for once
PT interpretation: Heavier weights, higher level, less recovery time needed!
Me: my legs feel like bambi
PT interpretation: she needs to run really fast now!
Me: I'm squatting a bit lower aren't I - that's progress
PT interpretation: she needs to squat holding a big heavy belgian bag!
Me: My heart is absolutely pounding
PT interpretation: excellent, let's keep it at that level!
Me: Have you just put the level up?
PT interpretation: she is finding this too easy if she can't tell!
Me: last set - hooray!
PT interpretation: right, one more set then!
Me: why can't I balance properly?
PT interpretation: she needs to do single leg pistol squats!
Me: god I hate jumping about
PT interpretation: she must jump, jump and jump some more!
Me: my arms are burning already!
PT interpretation: but not enough, feel that burn!
Me: Ooh I love this song
PT interpretation: go faster, keep up with it, don't stop!