We have found swim team amazing for our kid (age 9) with hypotonia. She's a much stronger kid and athlete, after a year of summer and club swim. But one other thing that has also helped. We installed a little indoor gym in a doorway, with a bar on it that they can switch out with things like swings and gymnastics rings. We only have it up during school year to help our ADHD kids regulate emotions and run off energy. But coincidentally the indoor gym has helped our 9 year old with upper body strength because she can't pass it without doing pull ups, flips and tricks on the bar and rings.