When will I learn my own limits, I thought, as I attempted an inverted needle on aerial silks, at Skylab in London. It’s exactly as it doesn’t sound: two pieces of long stretchy material are suspended from the ceiling. If you grab them high, jump off the ground with pointed toes, knees to your chest, in a “tuck”, you can spin backwards, straighten your legs, and before you know it, you are hanging upside down. I know it’s possible because I have seen it successfully executed, by the instructor, Star. When I try it, nothing on earth feels less likely. It’s ridiculous hubris even being in the room: no less absurd than thinking I could scale sheet glass because I’ve seen Spider-Man.

“This is quite hard,” Star begins, “and it hurts. The silks can squeeze, the aerial hoops are rough on your palms, and it takes quite a lot to even get off the ground.” The subtext is: “Suck it up! The only way to succeed is to fail a lot of times.” I find this motivational in theory; in practice, however, my body dances to its own tune.

We started with a French climb: grab the silk, high, with your hands; loop it round one foot; clamp it in place with the other. Now you’re stable, you should be able to shimmy up, without too much brute strength. I think, after about seven or eight days’ practice, I could have managed this: whereas we’d be talking months or years to nail the inverted needle and the birdy (a fiendish move: stabilise yourself by wrapping the silk round one foot. The downside is that your body weight is condensed into pressure on that foot.) “If you need help,” Star said at the start, “shout ‘help’.” I like your safe word,” I said. “Well, I used to say, ‘Shout Star’, but the first thing people forget under pressure is a name.” I didn’t need any help, but wanted to shout it anyway. “Help. I lack the backbone for this level of discomfort.”

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With an aerial hoop (a sturdy hoop, slightly smaller than the span of your arms, hanging from the ceiling) you can throw more impressive shapes with less strength or technique, but getting into it – and out again – is, in every sense, a white-knuckle ride. Whether you hold it from the side and hook one leg over (the starting point for a wonderful pose, shoulders forward, legs gracefully angled, flying), or by hanging off it like a monkey and kicking both legs up, there is still, unavoidably, a moment when you have to summon all your core strength, or fall on your head (there is a padded mat, so this isn’t quite the one-way ticket to casualty that it sounds).

Star also runs a class called Pop Fit, where you work on the muscles needed for aerial work; if I were dead set on it, I’d alternate with that. But I strongly preferred watching (even beginners look amazing when they pull off a pose) to doing it. Which is fine, right? It’s the circus. Someone needs to be in the audience.

What I learned

The three key moves to get into any pose are the tuck, the pike (legs pointed straight ahead, hinged at the hip, like an L-bracket), and the straddle.

• Find a class near you at supaclass.com.