Not specifically for exercise but I use electrolyte tablets or powders when I’m doing particular ‘activity’
I had a hard time many years ago running an event in July, extra embarrassing as I brought in crates of water and nagged everyone else to keep drinking, but failed to stop for myself
I started with SiS, but mostly use High5
When doing ‘proper’ sports, depending on the type of activity, you should use a selection with something in advance, during and after - to prepare yourself with energy, keep going and then recover your muscles etc
All the sports drinks brands have their ranges and some sell sets for a specific sport.
I keep my eye out for the deals.
If you’re preparing then powders are good, either in premeasured packets or tubs if you’re serious.
The tabs are most convenient though - I’ll put one or one and a half tabs into a small water bottle or up to two in a drinks container
If very mobile then there are gel shots too which you down in one rather than adding to water
High5 do good packs by sport, and I’ve used the cycling and running packs which each come with a different mix of the different types.
(A thing to keep an eye out for is that some sets have caffeine among them for a boost - so don’t be downing too many of them in one go)