help my jab

I work my heavy bag for a couple rounds of just throwing my jab. It helps me. I throw it as fast as I can and I make the bag move. If I double or triple and etc. I throw some hard some light, but my main motivation is always penetration. Get in fast and quick. I gave one of my sparring partners a nice bruise on his forehead after a couple of weeks working my jab; wasn't intentional, it was more about him needing to work his technique on 'getting in' than me looking to hurt someone. I do 12 rounds full on for 1:30, with a rest of 1:00 between. One of my straight punches work-outs has first, third, and fifth round is just jab; second, fourth, and sixth, just cross. then 7 and 8 are 1-2's, and so on. The point is to supplement my boxing workout at the boxing gym by throwing lots and lots of punches. As Matt Hughes said, you get better at fighting by fighting. So it is fair to say that you get better at punching by punching.

First by the way, I just found this site momments ago and will be checking it out... to the question on how to improve endurance and power with your jab. I have to throw out my answer here cause it seems to work well. One day I picked up my girls rubber coated hand weights and started punching the bag with them. You don't have to wrap up and put the gloves on either. Just grab the weights in your hands and start punching the bag with your jab techniques. The weight ends protect your hands so you can really focus on clenching your fist and throwing hard jabs. Do this the day of a fight and seems your jab speed, endurance and power seem to double overnight.

harleymsu is right. It would seem to me that you are trying to over maxmise onjthe power jab and no matter how good you are it makes it difficult to recoil the hand and throw with the same intensity. I have a lightening jab now which I can treble up and not lose intensity/power. The trick is to work on speed first; if you have 16oz gloves use those to hit the bag with; it's clumsy at first but when you can double up with these and it feels right; you have got it. shadow boxing with hand weights also helps to work the fast twitch fibres. I shadow box for 6 mins wiothout weights; then 9 minutes with 2 kg dumbells in each hand. Try it and all the best.