Yes, but the “variable speed” keyframes can be confusing and hard to work with when doing variable speed changes.
Another way you can try is to lay the clip on the timeline, set the initial speed you want (say 200%), razor blade the clip where you want to change speeds then adjust your speed on the second clip (to say 50%) then razor blade again where you want the speed to change again and adjust the 3rd clip back (to say 200%). Do it in just this order and DO NOT “roll the edit” after you make the speed changes or you will bugger it up.
You wont get those nice “variable speed ramps” you sometimes see out there but you usually want to do this sort of thing to music timing or a sound FX so it works nicely when it is all timed out well.
Hope this helps.
Richard Cooper
FrostLine Productions, LLC
Anchorage, Alaska
http://www.frostlineproductions.com