We did a "lactic threshold" set in swimming today. It looked easy on the board but it was actually much harder than it looked!

2x
1x50 Fast Fly, 30 sec rest and 100 Free descend to 80%
5-10 sec rest
1x50 Fast Back, 30 sec rest and 100 Free descend to 80%
5-10 sec rest
1x50 Fast Breast, 30 sec rest and 100 Free descend to 80%
5-10 sec rest
1x50 Fast Free, 30 sec rest and 100 Free descend to 80%
5-10 sec rest