Anecdotally we all know laughing is good for us, but these days science is supporting it too.
When you're at laughing yoga, it's impossible not to laugh. Laughing yoga is a 21- year-old practice taught around the world -- it's exercise; it's therapy; it's hilarious.
"No matter how bad your week's been, you're just super happy and you're just relaxed for the rest of the week," says laughter yogee James Wright.
From belly laughs to laughing scales to laughing centipedes, all forms of laughter can be found.
Today was Rebecca Cragnolini's first time.
"I thought it was going to be uncomfortable, but there were so many different activities, you didn't really have time to think about looking silly."
A recent Australian study looked at the impact of laughing yoga on corporate employees and found that general life satisfaction, mood, self-esteem, optimism and sense of control all rose after just one laughter yoga session.
"It's an excellent form of stress relief and a good workout," says Anita Sauer.
Similar findings came out of a study on kidney dialysis patients last year.
"This is about laughing for no reason at all. And some people might not have laughed for a really long time. They might be grieving; they might have had cancer," says laughter yoga teacher Hannah Airey.
"I've been feeling a bit down and I thought I'll come along and cheer myself up, and it certainly did that today," says Glenda Fearne.
Laughter yoga is increasing in popularity, with thousands of studios doing it the world over.
"I think it is becoming more acceptable. It's still pretty freaky and weird but it's about giving it a go," says Ms Airey.