Last week I couldn't match a 38s length timer so set a 39s interval today. I just managed to keep below 2:00min/100m for four 100m sets but in the second half of the session my pace faded away markedly. My last fast 100m set was done at 2:12min/100m pace which wasn't great.
This chart from Swimming Watch Tools illustrates that I am managing a higher cadence now and as some lengths have a low stroke count at a high turnover there are some faster paced lengths in the session.
I could feel that my arms were tired by the end of the session and even striving to gain pace I made negligible headway. However this intensity is the goal of the session; I really need to keep up the frequency of the programme to maintain the overload.