can anybody on here recommend the best i.e. mechanical running aids, I'm thinking of the puma-bot or other similar type aids that might be available, i am not sure if that puma bot is read in public?

if not mechanical running aids are there high speed bands which can attach to a wall or something else instead of another person, in which the speed or velocity can be controlled so you can choose how fast you can run, this would of course be more sprint based?