Dream Fitness, a 24-hour gym which has been operating in Bognor High Street since 2013, has moved to Durban Park after a planning application was approved.
The new gym will be the 'largest gym in Bognor Regis', according to its owner Gary Kellaway.
Gary said: "My wife and I started the gym because we wanted to offer the Bognor community something a but different than the traditional £40+ per month gym.
"We've expanded virtually every year, and have done well enough to have our second site in Selsey operating really well also.
"Lockdown has devastated us and our members, but we were adamant that we were not going to hide away and hope for the best. We wanted to use this period of intense stress and fear for the future and turn it in to something positive.
"That is why we've decided to trade in our 8,000 square feet high street gym and move over to a new premises that will be 18,000 square feet when compete."
Gary, who hopes to open the new gym in May, said the extra space 'means we can stock even more top class equipment' for 'all types of people to enjoy'.
He added: "On top of the equipment we'll also have two fitness studios which will be running around 50 classes per week for our members to enjoy.
"The past year has really showed how much the gym means to so many people, our members have supported us throughout and we can't wait to invite them back to the best version of our gym we have ever offered."