Nice screenshot, Atari ST version?
You have to wait for them to sync up and then just run through. The timing's right when both of them hit the bottom of their platforms at the same time; that's when you make a run for it. The second one is faster and has more distance to cover but it's just getting above head height by the time you've cleared the first one.
If you keep moving as soon as the level starts they're usually close to that stage by the time you get to them, otherwise you'll have to wait for them to sync up again.