Not familiar with that camera. Can you adjust any settings in video mode?
Basically the video stills are blurry because of shutter speed being too slow (for sharp stills, but this also help make video look more realistic).
If you can increase iso, this will decrease motion blur in video stills. It will also make the video look less "lifelike" when playing back in video mode.
It comes down to your goals. If your goal is coaching and critiqueinf form, etc, then you want sharp stills over beautiful video. If you are wanting the camera to make beautiful video, then you need to accept motion blur in your video stills.
I don't know of any camera that allows full manual control in autofocus mode. If you need autofocus mode, then iso probably is the only variable. Increase the iso to 400 or 800 and report back, I bet it solves your problem.