How much do you push yourself??

How much do you actually push yourself during training? I understand that everyone is different, but do you ever wonder if you could have done more or tried harder? Even when you are doing what you can, you cant actually feel your legs anymore as they feel like lead weights or you struggle to breath, when do you actually stop? How much recover time should you give yourself.  When you stop is it truly because you cant go on anymore, I know these maybe strange questions but I do wonder if things can be done better.

I think we all know by now, by biggest weakness has to be food, exercise isnt easy but I do work hard at it.  Coming second last week just got me thinking, the leading women Janet Smith was about 30 minutes a head of me, that means that she was running probably on average about 14km an hour through sand, as well as completing the obstacles which of course would slow anyone down, so she was running a lot faster than that.  Based on this, I had to ask myself, could I have gone harder/faster, the answer is YES I could but I dont think I could go that fast.  I know I need to improve on my overall obstacle training, building some confidence and completing them quickly and efficiently, rather than run, stop, think about it and then do.  I just need to DO!

Is there actually a right balance, trying to push your body to more than what is capable of, but without actually causing injury.  At the time it feels great, you can go harder and longer, but what are the long term affects on you muscles, bones and joints.

I also wonder if we had this when we were younger, what path we would have taken, could we have been fitter and stronger.  Being in your 30's is not quite the same as being in your 20's, but if I was doing the same thing then as what I am doing now, I wonder what the result would have been.  But there is no point thinking of that, there is nothing I can do to change my age, I just have to keep moving forward and to get better.  There are so many people out there that just inspire me in what they can do, all for different reasons, I am blessed to have come across these people and grateful to have everyone in my life.  At the end of the day, neither Dave nor I could have done this without the support we have received from family and old/new friends.