A 30-minute run, non-stop, on Saturday, before the longest run of the program so far tomorrow. Quicker pace, moderate length, and the Saturday rule in force: finish with the legs loose and the tank full.
Thirty minutes is shorter than recent Saturdays, and it should be - tomorrow is 22 km. The purpose of today is to keep the week's rhythm, shake out the power squats and intervals, and rehearse an easy cadence. Any speed you leave out today goes straight into tomorrow's last few kilometres.
Warm up, run comfortably, cool down, and keep it short if the legs ask. Eat and drink well through the day, plan the route, the water and the food for tomorrow, and get an early night.
Thirty easy-quick minutes, and then the day belongs to getting ready for twenty-two kilometres.
Make it Harder: Twenty minutes at the quicker pace, 10 as a jog, and leave it there.
Make it Easier: Jog the full 30 minutes and let tomorrow have all the effort.
