resisted running and...

Are resisted running and towing sprints good forms of speed training? To me it would seem that either form takes the body out of proper sprint mechanics. Anybody ever use these with effectivness? How cycling in preseason?

D there is a place for resistance training in workouts but in got to look at what types of resistance methods you want to employ and there benefits etc.also what amount of resistance is tolerable while still maintaining proper mechanical movements.

post what your ideas are as in what method are you thinking about,tyres,sledges,hills etc