Pool Pumpin'
the act of, or result of lifting weights or exercising (pushups, pull ups, etc.) right before going out to a pool party or the beach with the desire to engorge your muscles with blood, or produce a pump, in order to temporarily make them larger in order to impress the opposite sex.
Before that dude went to the pool party at Club La Vela, he must have been pool pumpin' to impress the ladies.