You cannot increase the frame rate for certain parts of a movie.
The entire movie has to have the same frame rate.
In your case, the only suggestion i can offer, is to position the legs, such that they seem to move very quickly and give the illusion of speed.
Hope that helps
Does that change the FPS of the whole thing? I wish there was a way i could zoom in on the timeline so i could edit it more in less time.
I was able to do following using stage.frameRate
SWF having frame by frame animation for 90 frames. First 30 frames played with 5 FPS, next 30 frames played with 30 FPS, last 30 frames played again with 5 FPS.
Is that what you want to achieve?
If yes do read help page below
and some examples like http://flashspeaksactionscript.com/dynamically-adjust-the-frame-rate-of-a-flash-animation/
That seems like the right idea! Thanks! Where does it show how to do it in the first one?
You can use eases. In order to use an ease you need have a motion tween depending on your animation it may be a shape or motion/classic tween (if you are using CS4 or later classic) Select which frame you would like the animation to be slowerer on and go to you properties and bring you ease down, and then do the same on that frame that you would like to be faster only increase the ease. (I might have it backwards but you get the idea)
Another option to to use math with you animation on the timeline, when controlling speed pay attention to how many frames you are using and your frame rate, Try on your faster portions of the animation having each frame be a new keyframe, but on your slower portions give each new keyframe a grap of 1 or 2 frames and add eases on those.
The third option os by using your motion editor, if you are familar with AfterEffects this will be easy for you, this has a lot of ease control, however because I am so in-grained in my flash ways I have not really liked it but if ou are new it might be a good place for you to learn how to animate.
Hope that helps