Not sure if this qualifies as a tool. My grandson has issues with bullies at school, so I set him up with a heavy bag to practice on in my son's garage. I set it up on a track system, so the bag slides out of the way when not in use. When it's not pinned in place, he can punch or kick it to see how far he can get it to slide in the track to test his power. The best part of the adventure is all three of us taking kickboxing classes together. Not cardio kickboxing, the real deal, mouth guards, hand-wraps, and shin-guards, where you bleed if you're not paying attention. Monday through Thursday are exercises and drills, Friday night is for sparring. The age spread is 13, 33 and 64, between me, my son and grandson. For the record, for people that have not sparred, it's not full out, knock out type sparring. It's decided before hand what power percentage we all agree on. Most often it's between 50 and 80 percent.
My son and grandson have an advantage due to the age difference. I have a slight advantage because I took classes for 3 years, 8 years ago. Grandson has 3 years of karate, son has 8 years in the army, so were not starting from scratch. It's a massive ego boost at my age to not be the first to get winded or tired, when everyone else is less than half my age. It's motivational for everyone else in the class, because nobody wants to get bested by the guy that's old enough to be their grandfather. I consider myself fortunate to be healthy enough to do this stuff with my son and grandson at my age. My dad died at 63, after years of health struggles, I'm 64 and kickboxing with my son and grandson. Thankful for every day I get, and that my family still likes me enough to include me in the fun stuff.