You officially have no excuse for being lazy.

Fitmob launched an iOS app today that connects people with convenient and fun group workouts in their city. The most interesting part is that the more you work out, the less you pay. How’s that for motivation?

Fitmob also announced today that it is backed by $9.75 million in funding from Mayfield Fund and Silicon Valley Bank.

“It is not that people don’t know how to do a pushup, it’s getting motivated to do that pushup,” said Fitmob’s CEO Raj Kapoor in an interview at the startup’s San Francisco office. “Motivation is people’s biggest problem, and the current fitness system is not set up for that. Fitmob is redefining the gym for this new era of social and mobile by creating neighborhood fitness communities.”

50.2 million Americans belong to a gym, and the industry generates $21.8 billion in the U.S. alone. The average cost of a gym membership is $55 a month, and a whopping 67% of people with gym memberships never use them.

With Fitmob, you sign up and pay for workouts from your phone. If you attend one Fitmob workout a week, it costs $15 a session. Two workouts a week cost $10 per workout, and those who come three times a week pay $5 a workout.

Kapoor said the idea for Fitmob came after meeting fitness legend Tony Horton, creator of the popular at-home workout dynasty P90X, who inspired him to examine the problems underlying the fitness industry.

His conclusion? People don’t like going to the gym.

“We have to rethink what fitness is,” Kapoor said. “Using your own body is practically all you need. We like to say that the ‘city is your gym.’ Each of our fitness communities has a great leader, and all the workouts are really fun and social. This isn’t about fitness tracking or watching workout videos, it’s about meeting up with people and putting down your phone.”

America’s sky-high obesity rates make encouraging physical fitness more important than ever. Kapoor said that the most successful models for making difficult behavioral changes, such as Weight Watchers and Alcoholics Anonymous, are about humans getting together to solve problems, support each other, and hold one another accountable. This is what Fitmob aims to do.

Fitmob’s amusingly titled workouts include “weapons of ass reduction,” “twerkout conditioning,” and “guru gone wild.” At launch, there are 30 workouts available a week in neighborhoods around San Francisco.

Fitmob’s model also helps certified fitness trainers generate extra income. Kapoor said there are 250,000 certified trainers in the U.S. and only 30% are utilized. Fitmob creates a system where they can hold their own workout sessions, without relying on a gym to give them classes to lead, and attract their own following.

Kapoor was one of the founders of Snapfish, which HP acquired for $300 million in 2005. He then joined Mayfield Ventures as a partner and was an early investor in Zimride, which went on to become Lyft.

“This could do for group workouts what Lyft and Airbnb did, by making use of under-utilized people and space,” Kapoor said. “The best businesses are a daily recurring habit. People think about fitness weekly, and fitness meetups are already happening, but we don’t yet have the regularity.”

Fitmob will continue to test the model in San Francisco before rolling it out in other cities.