Although bodybuilders have long experienced what is popularly known as "the pump", few have ever expressed the feeling that it imparts as eloquently as did Arnold Schwarzenegger in the 1977 documentary, Pumping Iron: "The greatest feeling you can get in a gym, or the most satisfying feeling you can get in the gym is... The Pump. Let's say you train your biceps. Blood is rushing into your muscles and that's what we call The Pump. Your muscles get a really tight feeling like your skin is going to explode any minute, and it's really tight - it's like somebody blowing air into it, into your muscle. It just blows up, and it feels really different. It feels fantastic. It's as satisfying to me as, uh, coming is, you know? As, ah, having sex with a woman and coming. And so can you believe how much I am in heaven? I am like, uh, getting the feeling of coming in a gym, I'm getting the feeling of coming at home, I'm getting the feeling of coming backstage when I pump up when I pose in front of 5,000 people, I get the same feeling, so I am coming day and night. I mean, it's terrific. Right? So you know, I am in heaven." Okay, so perhaps the man who was then known as the "Austrian Oak," piled it on a bit much. But the underlying purpose of Pumping Iron was to not only profile men such as Arnold and Lou Ferrigno but to inform the public about what really goes on in the subculture world of bodybuilding. Why did bodybuilders relish the idea of going to a gym day after day and blowing up their muscles to unprecedented proportions? Arnold's explanation of what the muscle pump did for him explained in easily understood terms the feeling of sheer joy that a bodybuilder or anyone who lifts weights derives from that fleeting, yet considerable experience of having a massive muscle pump.
But one question that often arises about the fabled pump is whether it's just a temporary cosmetic effect of looking bigger for a short time, or whether it contributes to true muscular hypertrophy or growth. To bodybuilders, obtaining a significant muscle pump always heralded the possibility of muscular growth. The reasoning for this was that a pump represented increased blood flow to working muscles. That blood delivered not only oxygen but also a plethora of growth-stimulating nutrients, such as amino acids, as well as anabolic hormones that included growth hormone and testosterone. We knew this was true even back in the dark ages of muscle science, over 40 years ago. Not getting a good pump when training any particular muscle was a downer; a sign that something was off, perhaps you didn't eat enough, or you lacked sufficient sleep. Sure enough, later research . . .