I wanted to build on Friday's bilateral breathing today and did sets at a range of stroke rates. As seems to be normal the first set of bilateral breathing was a struggle and I felt the pace was unsustainable even at 62SPM. I did a sequence of 200m sets at 64, 66 and 64 SPM and found the first 64SPM to be fastest. 66SPM felt to be above a critical speed.
To mix things up I then did 67m pairs of lengths at 68, 70 and 72SPM, acknowledging that it would be tending anaerobic and not suitable for any significant distance. Pleasingly the greater effort did give greater pace although maybe the workload became disproportionate; 70SPM being best for a 'fast' lengths? Importantly over this session the SPL didn't rise excessively, I always show a gradual increase due to fatigue.