Why is my body hard to move?

I'm still new to lucid dreaming, but I've noticed a pattern in how I become aware that I'm dreaming: I'll see a bunch of different clocks throughout my home, all with different times and I suddenly realize that it's all a dream. The thing is, before I become lucid and it's just a normal dream, I'll feel perfectly fine. But right when I become aware of what's happening, it feels like a surge of electricity jolts through my body and my legs go out. It's like I'm ridiculously high and unable to move. It causes me to be very slow. Why is this? Is there something I can do to stop my body from becoming heavy and hard to move? Thanks. :)

this is a common problem in the beginning. Here is what I think happens. Your brain is attempting to move using the normal pathways it has use in waking life. It sends similar impulse out, but only encounters your sleeping body. Your body is being subdued by the chemical processes that keep you from flailing around while asleep. In your dream mixed and frustrated impulses tell you that something has gone wrong and no good result resulted from your attempt to move. The trick here is to come to terms with the fact that movement in the dream is different. It does not require nerve impulse being sent to the body. the trick is simply to imagine that the movement is already happening and then try to picture the movement. It is like daydreaming much more than it is like waking activity. It will take some practice, but you will get it. The next time it happens, stop trying to move at all. Instead relax and picture yourself being blown forward, and you just drifting forward with no motion needed. After your brain catches on to the difference you should have a better time at moving. Good luck.