Diet and exercise are both important to good physical fitness. And cardio, especially for hunters, is very important. Your weight should be what the doctor's chart says it should be for your height.
I'm 5'11" and currently weigh 190. The chart says I should be 170. I'll be happy if I get to 180. Last time I got down to 175 I was skinny and starving all the time, but I could run up and down the mountain without breathing heavy. Trouble is i can't stay at that weight without starving.
If I can get down to 180 again and stay there for a year, I'll try to get down to 175 again and see if it's possible without starving.
BTW, I'm going to be 55 this year, so this is not easy for me at all.