I will be doing a lot of smash drills.. Probably like 100 a day but my concern is will this wear out my wrist.. Anyone here tried something like this before?
Wear out your wrist? Like permanently? Probably if you do smash drills constantly for a long time. Short term definitely, smashes are quite a physical shot, so you can expect to be sore or tired after doing a lot of them.
It's hard to say. If I'm doing full training I'll easily do 100 or more in the day. But I think 7 days a week it'd be bad for me.
Usually a coach will do sets. One set is how much shuttle he can hold in his hands. Around 20 or so. Depending on how much time you want to spend you might end up with 10 + sets. But that's hardly 20 mins. In the grand perspective of things, 20 mins of exercise is just the warm up!