Why Do People's Veins Pop Out When They're Super-Jacked?

Jason Hoffman/Thrillist
Jason Hoffman/Thrillist

In addition to a willingness to grunt loudly and an affinity for carb cycling, there's something else ripped people seem to have in common -- a vast network of protruding veins.

Popped-out veins aren't just a blood-drawing nurse's dream; they're a key indicator of that coveted bodybuilder look. You're not hardcore until your blood-carrying pathways jut out like an arm full of hernias. But what causes them in the first place?

Bigger muscles require more blood

Maintaining so much muscle mass requires the usual suspects: discipline, heavy weights, eating copious amounts of protein, talking about the copious amounts of protein you eat. It also means your body itself has to work to keep said muscles big and functional.

"Bigger muscles demand more blood," Paul Salter, RD, CSCS, and nutrition editor at Bodybuilding.com, says. "When you accrue significant muscle mass, your body adapts by expanding its blood flow network; thus, veins become more prominent in specific areas."

This means the more muscle mass you have, the more vascular you'll appear. Don't think your veins are big enough? Hit the weight room and build up that muscle mass, bro! 

If you work out a lot, you probably have leaner mass

All the muscles in the world mean nothing if they're hidden underneath layers of fat. Sure, maybe you know they're there, but try explaining that to people who only see a muffin top where six-pack abs should be. Same goes for veins. 

"The one literal road block that keeps veins from seeing the light of day is the amount of body fat you have," Salter says. "If you have less body fat, you're likely to have fat immediately beneath the skin, which means your veins are less likely to break through and protrude outward, or at least be more visible."

Shedding pounds is the biggest thing you can do to unleash your giant, sexy veins. So even if you just have those last 5lbs to lose, it could mean the difference between pathetically smooth arms or a badass exposed blood circulation system. 

Sometimes it comes down to genetics

Unfortunately, some people could work out all day and get their body-fat percentages down to the single digits and still not see any protruding veins. What horror! That's thanks to the wonderful grab bag of your genes.

"Vascularity is heavily influenced by genetics," Salter points out. If blood courses through your body, but no veins pop out to prove it, are you really even alive? 

If big, bulging muscles and a constant IV drip of protein shakes aren't enough to make you feel like a true bodybuilder, then check out these tips to train for veins. But remember, you don't need veins to do what really matters: fill out your competition shorts, punctuate every rep with loud grunts, or tell people just how much you can squat.

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Christina Stiehl is a Health and fitness staff writer for Thrillist who has sexy protruding veins under these doughy arms, she swears. Follow her on Twitter @ChristinaStiehl.