So we popped gymwards s'morning and Timmy said "No swimming, you are still blowing your nose, do you want to do a long cycle or one with fast bursts?" so I cycled for 20 mins going as fast as feck from 4.5 - 5 mins, same at 10, 15 and 20.
Dunno, I did, IIRC, 5km-ish which averages out at 15kmh