This is not medical advice. You should see a MD before any exercise program. It is quite easy to hurt yourself on this board. The board is extremely buoyant and can pop up quickly hitting yourself or others. It is covered with a thin layer of slightly soft foam but will hurt if you hit yourself in the face. It was easy for me to wrench my back, shoulders, neck and hips trying to get situated on the board. If drowning is not your thing you need to be able to swim when you lose control of the board which you will. Wearing a vest or floats distorts use of the the board.
I like this board. I have played with this board a great deal. It feels like it teaches symmetry between the left and right side. I sit, tall kneel, (video shows low kneel sitting on haunches) and stand while swimming with crawl stroke bringing each arm clear of water. While sitting I can bring my arms overhead with up to ten pounds of weight which sends my whole body and head under water while trying to stay balanced. (it is useful to have swimmers goggles. Much more weight and I am completely under water for the whole time which makes it tough to breathe.) Instead of trying to stabilize consciously with the abdominal muscles I feel in trying to stay balanced on the board a more natural stabilization takes place. There are all sorts of upper and lower exercises I can do with the board. The core work seems to happen naturally in response to balancing. I can get a decent aerobic workout by sitting doing a crawl with legs and arms forward and sitting backstroke with legs and arms backward. It just depends on how hard I am willing to work. It feels more enjoyable than normal swimming because my head usually is clear of the water without keeping my neck extended. Most exercise can be done without much load at first then increased as I need. The main problem I found is getting competent on the board without hurting myself. Having a pool with shallow and deep water is necessary to get full benefit.