Intensity: Depends to a great extent on how well the athlete has recovered from previous workload when these speed development sessions come around.
The simple answer is that I would ask them to be intelligent and sensitised to their own body, thereby doing the training as the feel able.
During GPP it is not that impressive, but once we get into the Transition phase and certainly once we are into competition period, these runs are fairly good. I mean, they work into their speed. So in GPP it’s about speed built through rhythm, relaxation and mechanics.
The words I always use are: “Don’t fight it. Don’t look for something that’s not there yet.”
As long as you run relaxed, you should stay free of injury whatever you do. If the speed comes early, wonderful. But it will be there by the time you need it - in the competition phase.