is there a difference in running outside, on a treadmill, or riding an excersice bike in making me faster?

Question

also i should mention i am trying to speed up for track and i haven done serious running in years, i have stamina because of boxing but thats it.

Answer 1

running outside is the best, but if its raining out or i cant get out, i use the treadmill, its not as good, but its ok.

Answer 2

outside is sometimes better because of the rough terrian and the different slopes/hills that occur. you're body isnt used to that.
i run on the treadmill though and have gained endurance.