I think Kiwi John is on the money: it doesn’t matter much what is in the circuit, how many stations, how far apart. I just put it in there originally because it was a gut busting session based around power and certainly endurance. I just divided up a grass field (using the outlines for a soccer, hockey etc. field).
The circuit usually takes around 8mins to 9mins for someone who is not very advanced in their endurance training but it can be done in under 7mins by someone not too torn down but already very fit for this kind of training.
I introduced the circuit because I felt “my” sprinters sometimes became a bit too precious, fine-tuned, delicate. I wanted to rough them up a bit, make them a bit more rugged, disturb any complacency they may have about their place in the world of the toughest sports. Footballers do this sort of primitive circuit endurance training all the time.
In terms of “effort” the first time athletes do the circuit there is no pressure. They just need to complete the distance. Then as they get fitter they can think about racing the clock. We do the circuit twice with a full recovery between, in the same session, on a back-up day during weeks four and five of the GPP. So that’s 4-times per basic 6-week GPP. And the GPP cycle is repeated. So the power circuit will be done a total of 8 times over the course of the 12-weeks of GPP.
** “kiwi John”, if you read this could you please re-post that photo transfer website link you gave me years ago. I have left my job and all that kind of stuff unfortunately I left on the office computer system which I no longer have access to. Thanks John.