A great day with perfect riding conditions. A NW3 wind and around 12C. A gentle Z2 warmup ride of 10km to a stretch that allowed me to ride the interval with a tail wind to increase cadence and pull 40kph. Felt pretty good and the rest interval was done at ~28kph into the wind. There's a real quick change from around 170bpm from sub-anaerobic to anaerobic. Good to get the legs used to pumping out the waste. I feel fine today in the legs. On any given ride, my legs suffer more than the lungs. This is therefore good training for me.