"It was a miserable experience," she says.
That day, she gave up, but an idea was born.
Fast forward seven years, and the 34-year-old's ClassPass fitness subscription business is a global phenomenon valued at $US470 million ($645 million).
"In the beginning, the person I was trying to build a product for was someone like me," she told news.com.au ahead of her July trip to Australia, where the workout class app has been a raging success.
"I was scared to walk into a bootcamp class, I didn't know where there was a yoga class near me. I do think a lot of people feel, even if you fall off working out for a couple of months, you get scared again."
And Payal had to overcome a string of setbacks - even failures - before her tenacity paid off. ClassPass started life as a workout class search engine called Classivity, and it didn't work. "We had press, but the product wasn't working," she says.
"I felt like a fraud. It wasn't a real product. I went through having to downsize my team, get an engineering team to build a new product. Sometimes you have to make difficult decisions for your company. You can't be scared."
The product was reborn as the ClassPass app, where users pay a monthly fee and can attend a range of different boutique workout classes and gyms - from pilates to underwater cycling to spin/yoga fusion classes.
It was a huge success, and has now launched in 39 cities around the world, with more than 30 million reservations made at 8900 studios since 2013.
But there were further hiccups.
Costs rose as people took more classes, and a slew of copycat competitors added to the pressure.
In November, the business dropped its unlimited classes option and users were furious
"We simply couldn't make the plan work for our business," Payal explained at the time.
It doesn't seem to have done the company too much harm at present.
ClassPass this month raised more funding, albeit at a lower share price, increasing its valuation from $645 million.
The MIT (Massachusetts Institute of Technology) graduate says what's most important to her is that people go to classes and enjoy fitness.
"No one works out and feels bad after. It's personalised, social and feels like an experience. It's less, 'Oh my god, I've got to work out,' you go to do something. Let's make it exciting.
"Having variety in your fitness routine is good for your body. Four years ago, I didn't know what a plank was. Now I can hold one for up to five minutes. I go to barre class, bootcamps, dance, cardio, trampoline class and reformer.
"I do think people are scared to try new things."
Fear is a big theme for Payal, who believe this is what holds people back from getting to where they want to be. But when I wonder if this applies most pertinently to women, she turns it around.
"Try not to make it about gender at all. All you can focus on is your strength. Do whatever you need to be confident."
"Early on, I'd wear business suits to meetings, and it wasn't me. I started wearing my Lululemon leggings and it was more natural. The best thing I can do is be me in any room.
"You have to set yourself up to succeed, no one's going to do it for you."