After work I had enough enthusiasm to start the swims for week 5. It called for 7 sets of 400m and I started with 200m warm up. The latter wasn't on the programme and I think I might skip it in future! I thought I did it sensibly although the water was calm and I had an empty lane so that I could go at my own pace. This combination resulted in a clear 200m warm-up PB:
I started the main sets gently knowing that there was a lot of work ahead but even then I lost pace through the 75 minutes from 2:20min/100 to 2:32min/100m. I suspect that I found the session hard because I haven't done Session 1 consistently though the first 4 weeks.