Jonas said the club was an iconic facility.
"A huge thank you must go to Jens and Karen Bukholt, whose vision and astute management has left a lasting legacy for the Whanganui community, the life members of the club, who have supported over many years, and the committee who have worked tirelessly," he said.
"We will remember with gratitude, Julia Murray, interim manager, and the business community for digging deep and supporting the club when times were tough."
Annette Cox, the new Wanganui Boys and Girls Gym operations manager, was excited about the future.
"The Wanganui Boys and Girls Gym Club is a fantastic community space for Whanganui's youth to learn and love their sport.
"The club is a place for our tamariki to grow in confidence, make friends and most importantly have fun. It's never just about the sport. The team and I, under the mantle of Sport Whanganui, have the structure we need to plan and deliver on a bright future for the club."
Jonas said having the club ties in well with Sport Whanganui's base at Springvale Park, which includes the likes of Jubilee Stadium and the Splash Centre.
"Acquiring the club certainly fits in with our new strategy. 'Fun, fitness and fundamentals' was a term used years ago and that could not be more applicable now."