I normally 'run' at 5mph and walk at 4mph - both on the treadmill. Today I did w5r2 and ran at that speed but walked at 3.5 to get my Breath back a bit.
I am dreading the next run - the 20 minute one! I think I will slow it down a bit but am wondering if that is the right thing to do and if so whether to slow it to 4 or 4.5
The right speed is the one that lets you finish! Honestly you will be much happier completing 20 minutes at whatever speed than running faster and having to pull up.
Get over the hurdle of keeping going for 20 minutes by hook or by crook, you can always try it faster next time 
Can't say anything more than Greg, the right speed is the one that gets you to 20 minutes.
What is the speed needed to do 5km in 30 minutes
what speeds do you walk/run?
Not a natural runner... What speed?
On W2 - What speed on treadmill?
For Graduates: What was your speed at (or near) the time of graduation?
