I have always struggled with armpump for as long as I have been riding..3 years. I have never stopped riding because I was too tired but rather because I could not feel my hands anymore. I have tried almost everything including running 3 miles a day. I picked up on this new exercise that has pretty much eliminated armpump for me. Its turning anything (pipe, weight, broom handle) using your hands. Just hold your item of choice out in front of you and roll it over and over with both hands until you can't do it anymore. You will most likely feel it on the top of your forearm. Only need 1 set. If this becomes too easy try using a heavier item or attach a weight with a string to it and roll the weight up the the bar and then back down. I have had 3 rides with this technique. The last ride was at a track that caused me armpump in 2-3 laps guaranteed. I avoided going to the track for this reason. Huge braking bumps combined with huge jumps and high speeds just pummeled my forearms til I couldn't hold on. This time my skin wore out before my forearm muscles. Got blood blisters on my hands from riding so much! Also, for those of you suffer from hand/finger cramps instead of actual forearm pump (like me), this solved that too. And the good news for the lazy folks is I have not done anything cardio wise during this time. I have never been as sore as I am now cause I could never ride long enuff to get sore in the past. Give it a try. Its easy and there's nothing to lose.