You could get a parachute, have someone put a bungee cord around your waist and pull, or get a resisted running device you could use in a hall way or indoor track.
They are ok but not perfect. One of the biggest problems is that if you run with them outside a gust of wind can pull you off balance and really negatively affect sprint mechanics. In the GPP I don't think this issue is enough of a reason to avoid them if you don't have any other alternatives.
but im not sure which size to get, still trying to decide over the Medium and Large. Im 5'10, 144 lbs, 11.25 PR. anyone have suggestions on what size i should get? hopefully i can get quick responses because im trying to get it before saturday.
thats what im thinking too, but on his site, charlie francis says that resistance training products (sleds, chutes, etc) should not make so much resistance that a sprinters form and mechanics would be hindered. but then again, maybe the Medium wont give me enough resistance. Ah, im confused!
I'd say go with medium, especially considering this chart with recommendations based on weight (at bottom). I think at ~150lbs a large parachute would give too much resistance and gusts of wind would not be good at all.
The discrepancy you guys are noting is one of the problems with chutes. The resistance they provide can vary widely based on construction and air conditions.