Too much potassium has the potential for arrhythmia, but you would be hard pressed to eat that much. A potassium supplement is cheap. Hydration and and a potassium supplement are probably good. Too many
can block you up, too. Hydration hydration hydration and some exercises that involve the upper extremity might help, james...... If we took a poll as to who gets arm pump and their occupation, I would say those that perform labor intensive jobs (not all are blue collar--say, oh, I don't know--orthopedic surgery?) have less of a problem with arm pump. Like I said previously, it is most likely could be considered like form of shin splints, but in the arms. (please see early comments on exercise induced compartment syndrome). You have to train for ride.......not ride the train......