From the streets of Huntington Beach, California to the parks of New York City, the sweat-soaked street performers across America and beyond find new ways to make your heart race while you’re casually strolling by on a weekend afternoon.

Street performance has been on display for the general populace since the first days of recorded history. There’s always been a showmanship to the acts that dominate marketplaces in the largest metropolitan areas. But, it’s only recently that those performers have added a layer of daring and bravado to their shows; going from troubadours and street musicians to performers that excite with acrobatic displays more suited for a Barnum and Bailey circus than the corner of the park.

Street performances started out as low-level affairs with singing and dancing, but then graduated to more physically taxing exhibitions highlighting superior body control and unthinkable physical durability and courage. Plus, when you’re performing for a fickle crowd, like city pedestrians, you have to keep up a constantly animated dialogue with your audience and always move your body—or risk losing your onlookers. There is no rest because the moment the performers stop, the instrument case, coffee pail or simple Styrofoam cup will grow empty with each passing minute of downtime. Or, they’ll run off with your boom box.

Most subway and park performers sing or play an instrument. There are a capella groups from New York City to Chicago, or a blues guitarist in California. There’s a man on the street in New Orleans who can bleed some soul with just a few lyrics. Performance usually involves song and dance, but that’s not always the case as the following street performers prove.

There are feats of balance and body control like this ladder-equalizer in front of Boston’s Faneuil Hall; a man in Times Square balancing a rotating lawn-mower on his face as spectators throw lettuce up to be sliced by the sharp blade. Then, there is this man in Thailand who steadies four Contact Balls on his head in a busy market. One sphere on top of the other in a conical edifice composed of concentration and harmony with the spheres. He rotates six more Contact Balls between his hands in a circular motion while the others rest precariously on his head. It’s remarkable to watch these street acts do their shows.

In China, a former national champion gymnast performs for an entire workday in the crowded subway system. He ruptured his Achilles tendon, and the Chinese Gymnastics Governing Body left him to rot. He took his skills and went underground (literally) where he wows the busy Chinese commuters.

It’s not just the gymnasts or singers and dancers, but the jumpers that really raise the pressure of street performance.

You can see the aerial feats at a school where a boy jumps over 11 students lying in a bed of grass, but grass does not encompass a true street performance—just a nice trick to impress the kids. The same could be said for this gymnast that jumps a row of 11 people with the added help of the springs in a gymnastic mat. No, the real Adrenalists jump from the concrete and risk cracking their head on the ground or injuring the participants brave enough to stand as obstacles.

That’s why these street performers are real-life superheroes. They run at a line of standing people and flip over them onto the cement waiting on the other side. If you’ve ever watched these tumbling acts along a California boardwalk, a New York Park, or anywhere else in the world, you know they’re risking serious injury if they don’t make the jump. Not only that, but the volunteers for their human barriers are also risking injury. These buskers have to convince normal pedestrians to risk their own safety. They are true Adrenalist men and women. Make sure to stop and wonder at their grace and spirited displays of athleticism the next time you see a crowd gathering. You’ll want to see they’re showcasing.