i haven't gotten arm pump in....forever it seems.....i just kinda learned to ride loose, like i was riding in sand. that and i haven't been riding any high power bikes  

yz4me:
relax more when your riding...again overall body condition is a huge part...I workout three to four times a week and do cardio aswell but what I found to be the only thing to get rid of the arm pump is to use "grippers" you know the hand held squeeze things I found out a couple of years ago that they seem to work the best and you can do it anywhere I have one in the truck one in the van and one at work...trust me they will do the trick....and ride,ride,ride.

Funny you should say that as I bought a pair of the nut-crackin lookin things today. I spend a whole lot of time driving in my work truck and these will help the time pass. And I guess the nuts will be a good source of protein. lol    

I tried relaxing more when I ride and it has really helped to reduce the arm pump. I was white knuckling the bars mostly on jumps. I still tend to hold on very tight when I jump. I always rode trails and hill climbing when I was younger, but now I am trying the mx track and learning the jumps and turns and stuff. A lot of fun and a great work out. Three days of riding and my arms, back, legs, abs are all sore. Its great though because I sold the idea of a new bike and mx riding to the wife telling her how it will get me in shape and take some weight off as well. Thanks for all the suggestions.  

crfrdr:
I tried relaxing more when I ride and it has really helped to reduce the arm pump. I was white knuckling the bars mostly on jumps. I still tend to hold on very tight when I jump. I always rode trails and hill climbing when I was younger, but now I am trying the mx track and learning the jumps and turns and stuff. A lot of fun and a great work out. Three days of riding and my arms, back, legs, abs are all sore. Its great though because I sold the idea of a new bike and mx riding to the wife telling her how it will get me in shape and take some weight off as well. Thanks for all the suggestions.

U got it !! I think its awesome exercise. when I come back from a trail ride or the track, i'm wiped-total  work out!! The only thinks i'm not sure how long my old knees are gonna take it for.  

I bought some cheap weights from Argos and have mostly been working on making my forearms stronger, also getting a couple of squash balls, and squeezing them repeatedly until you have to stop feels the same as arm pump and helps to prevent it by training this way. Apparently doing press-ups on your knuckles strengthens your wrists and forearms. I would recommend weight training as I no longer get arm pump until i've been riding for a couple of hours.
Hope this helps  

First, do plenty of arm exercises.Cheap easy exercise,get a pair of needle nose plyers and squeeze a penny in them as hards as you can and as long as you can. Second make sure you have good grips and gloves. If it feels like your grip is slipping you will grip harder. When you first start feeling the arm pump tell your self to ease up on your grip. It should help. If you grips or gloves get wet or muddy you will notice arm pump faster. I have rode a 110 mile cross country with out gloves because of rain. I didn't have pump.  

I only get arm pump the first half hour of riding. I just take my hands of the bar and skake them out. After i get usedke mo to the biving around I don't have to grip as hard any more and it goes away. One time I went out to the desert for three days. I only had arm pump the first day because the 2nd and 3rd I was used to it and didn't have to re ajust to the bike and terrain  

the reson you get arm pump is because normally your muscles get tense and then relax. while you are riding your muscles do not get the chance to relax especially mx. this is why you get arm pump. while you are riding hold onto the bike with your legs. it will help your jumping, too. if you can learn to hold on with your legs and not your arms then you will feel more comfortable and relaxed in the air.

i saw something on the internet about how to cure it and prevent it, but i cant remember where. they said to stretch a lot. before riding and mostly after you ride. if you do not stretch after you ride your muscles will tense up and stay like that until next you ride and you will get arm pump again next time you ride.

also good stuff to do is put your arm straight out and put your hand flat like you are going to push on a wall. now pull back on your fingers about in the middle of them, all of them at the same time. and pull back towards your shoulder.

also put your elbow at a 90 degree angle with the palm side of your hand up. and rub your forarm with your knuckles.  

that rope/stich and weights trick works wonders with me