Planet Fitness said this week that it will open 225 gyms this year.
The gym chain has been on a growth streak in recent years.
It has more than 1,800 gyms in the United States, an uptick of about 60% compared to three years ago.
The company is one of the hottest stocks in retail: Shares ofhave climbed more than 400% over the past four years.
Investors are convinced that Planet Fitness has runway to grow by chasing the 80% of Americans who don't belong to a gym.