what exactly is this workout?

Today was our speed day at practice.
Our coach had us do 3x30, 2x40 (out of blocks), and 2x125. all of these were at 95%.

I have heard that this sends mixed signals to your body. Arent the 30s and 40s working on a totally diff. system then the 125s. Is there any benefit in doing this in one day? Could it have hurt more than helped…?

Yes, running 30m and 120m at 95% are 2 different things for the body.
BTW, what’s the point of running 30m at 95%, was it a sort of warm-up? As far i’m concerned, i don’t see the point, especially out of blocks, if not to check precise technical points. But difficult to judge as i don’t know the training context. Why not asking your coach, what does he think?

We run 30’s put of blocks timed to go over acceleration mechanics 95% which i consider 100% relaxed. However we already spoke about why 40 meters is not a good training distance as it is usually the transition period from accel. to max velocity so its like distance in no mans land. (As soon as your starting to get up you stop) going form 30’s then to 50-60’s are a better choice.

As far as the 120’s after accel development i dont see why you would want to train speed enduracne on the same day as acceleration. Can anyone comment from a physiological standpoint why this may not be a good idea?