Rt=Rep Time (Spikes)
P1=PR Time (Spikes)
Sp=Speed Percentage (the “%” below)
This is a spreadsheet screenshot I used for this formula. The only thing you’ll have to do is know the PR times and then plug them into this formula based on what Rep Time you want.
Using it on myself it looks like this:
If you run w/o spikes like I do many times in my neighborhood at night then do this for your PR times if you haven’t timed them in your trainers:
100m – add ~7%
200m – add ~5.6%
400m – add ~4.2%
If you just want to figure out the ones for your workout select the Rep Distances for your workout and solves those and do them at the according Rep Range.