Hi, back again for some help finding a book 
Ok from what I remember and it is not much 
A planet with heavy gravity and killer plants. The people raised there have increase strength and have been trained with “super” reflexes. They have guns strapped to their wrist with a wire attached. The gun is deployed with certain movements of their wrist/hand.
A guy, say from earth, has to go there and is of course weak in the higher gravity. He ends up learning how to use those guns, which is quite painful.
The only other thing I can remember is that the plants are actively trying to kill everyone there.
Hope someone can help me with this, been so many years since i’ve read this book and would love to read it again.
