Excellent advice I wish I had when my oldest was young. The author of this piece needs to see this post by you. As a mom to a thrill seeking ADHD kid, I remember my ex suggesting that we take competitive cheer away from our daughter when she continued her distressing behaviors; however, this is one of the few times I got parenting 'right.' I responded with "Competitive cheer is the only thing she's doing right/well now. We can't take away the only thing that makes her feel good."
I would suggest some High Intensity Interval Training, boxing, running, or whatever exercise that will be intense enough for the longest amount of time in order to get the endorphin and dopamine boost. Intense exercise truly helps my daughters, my sister, and me.