An inquest is likely to be opened in the next few weeks after the man, who has not been named by police, died on Sunday [September 30] evening.
Emergency services were called to the facility in Market Square [which backs onto Royal Victoria Place] around 7.30pm.
PureGym offers members 24-hour access and closed immediately after the incident, reopening on Monday. A spokesman said: “On Sunday evening, one of our members suffered a heart attack whilst in the Tunbridge Wells gym.
“Despite the best efforts of our team and the emergency services, the member could not be saved and has tragically passed away.
“We took the decision to close the gym overnight and have now re-opened.
“We are deeply saddened by these events and our thoughts are with the member’s family and friends.” South East Coast Ambulance attended shortly after 7.30pm following reports the man had collapsed. The force said the man died at the scene.