NSV - Conversation with Trainer...

So I wanted to share with everyone a conversation I had at my new gym yesterday with one of the trainers. I've recently joined this gym within the last week and noticed this one trainer who's quite bulky watching my workouts since. He finally approached me last night and asked if I was a new member and if I was training for anything in particular. I mentioned not specifically but was looking to keep my body fat percentage around 17-19% and he asked how that was going and I told him I'm at 18%. He then asked what I feel is the typical trainer question, "What are you doing to ensure you meet this goal" or in other words "How is your eating going". He was surprised to hear I keep a diary via MFP which includes documenting my protein intake. I also mentioned to him that I am always looking to keep my heart rate at a burning rate to which he asked what mine was. Being that I was gifted a Polar FT7 I was able to tell him my average heart-rate is 158 which is 72% of my max and he was like "impressive". My range to burn is 154-187 bpm....

I consider this a NSV as it confirms that what I'm doing is on track and my knowledge is accurate from my research. The old me would have been quite intimidated by having such a conversation with a trainer like this dude but instead I was quite confident and knew my facts on myself which impressed him.

He did give me an interesting tip which I'm still mulling over and it's that he mentioned I should include 15-20 minutes of cardio in the middle of my workouts. I told him that I didn't see how this would spike my heart-rate and I'm not looking to be a distance biker or anything. Yet he mentioned the benefit is it provides a break to my muscles from the weight training. Can anyone knowledgeable in this area provide any confirmation or further feedback on this point? Appreciate any and all feedback as without MFP and all the support this conversation could've went quite different....