Can I ask an idiot question here?

So I've been doing P90X for about a week and a half now. When I finish a workout, sometimes I feel like I didn't put it as much effort and as I should have.

However what I'm in the middle of the workout, I feel like I'm giving it my all. And when I say all, I mean like 90% because I do want to save my energy to be able to complete the rest of the workout. P90X is an hour long (sometimes an hour and a half) workout so I don't want to die early and not be able to complete it.

Maybe I'm just making excuses. What you guys think? You guys have the same thoughts when you work out?
---
pojr
I summon it. You spell it.

Oh man the fitness topic died so here's another one

[none]

[none]

---