I understand why you are asking the question but I think there's a question you need to ask yourself and that is what do you expect from a cycle?

The reason I understand is because I have just started my first ever cycle. I reached my natural peak about 15 years ago and although I try I know I will never get anywhere near that without a little extra test. Your question is whether you have reached your peak and are trying to retain it or whether you are now trying to attain something you never had before. If you have never bulked are you really aware of how much food, especially protein you need to eat and keep on eating to get and 'stay' big? The problem you will have otherwise is that whatever you gain on cycle will more or less instantly disappear unless you continue with that sort of eating regime. If you are prepared to start eating big while on cycle then you should probably have a go at eating big for a while to see where that gets you before doing a cycle.

As I said at the beginning tho, if you have been big (muscular not fat) and even tho you eat big you just can't get big again due to low test then I know where you are coming from. My guess and it is a guess is that at 140lbs you have a fast metabolism rather than you train like an Olympic athlete and that means unfortunately (for you anyway) you have to eat a lot more than I do to grow.

Let us all know your situation and I'm sure you will get more targeted advice.

The other bit of advice I would add is do you know the difference between high intensity crossfit style training and muscle building training? This sounds a bit rude asking this but if you don't it is important that you find out. Because there is a difference and you'll have a job bulking up too much doing crossfit. You'll be superfit, just not that huge.

Good luck whatever the case.