Get the total time. Then subtract the rest. The rest is 5-seconds times 5-times. The rest time is 25-seconds. Then divide the swimming time by 6 and get the 100-pace, as per Kevin Kinel.
The 100-pace times is called Cruise 1 interval.
Add 5 seconds to the Cruise 1 interval to get the swimmer's Cruise 2 interval.
Add 10-seconds to the Cruise 1 interval to get the swimmer's Cruise 3 interval.
- Swimmer departs on the first 100 with the pace clock or stop watch at 0:00.
- Swimmer does a time of 1:10 for the first 100. Clock at 1:10.
- Swimmer rests for 5-seconds after the first 100. Then departs on second 100. Clock at 1:15.
- Swimmer returns from second 100, doing a 1:15 swim. Clock at 2:30.
- Swimmer rests for 5-seconds after the second 100. Then departs on third 100. Clock at 2:35.
- Swimmer does the third 100 and swims a 1:16 time. Clock at 3:49.
- Swimmer rests for 5-seconds after the third 100. Then departs on fourth 100. Clock at 3:54.
- Swimmer does a time of 1:20 for the fourth 100. Ugh. Clock at 5:14.
- Swimmer rests for 5-seconds after the fourth 100 and then departs for fifth 100. Clock at 5:19.
- Swimmer does a time of 1:15 for the fifth 100. Clock at 6:34.
- Swimmer rests for 5-seconds and departs on the sixth 100. Clock at 6:39.
- Swimmer does a 1:10 on the sixth 100. Clock at 7:49.
Resulting math of example swimmer
- Total time of the set with swims and rest is 7:49. Calculation: 7:49 = 915 seconds.
- Subtract the rest of 25 seconds gives a swim time of 7:24. Calculation 915 minus 25 = 890 seconds.
- Divide the swim time, 7:24 by the number of 100s. Calculation: 890 divide by 6 = 148.3
- Math to go to seconds is 7 minutes x 60 = 420 + 24 extra seconds = 444 total seconds.
- Divide total seconds of swimming, 444, by 6 repetitions (did 6 x 100s), = 74 seconds. Calculation 74 seconds = (74-60) = 1:14.
- Cruise Interval #1 = 1:14 + :05 = 1:19
- Cruise Interval #2 = 1:14 + :10 = 1:24
- Cruise Interval #3 = 1:14 + :15 = 1:29
Real World Results
On December 12, 2019, two swimmers at The Ellis School, did the set.
- Total time: 17.31
- Swim time: 17:06
- Total seconds swimming is 1,026
- Divided by 6 = 171 seconds = 2:51 average per 100
- Cruise interval 1 = 2:56
- Cruise interval 2 = 3:01
- Cruse interval 3 = 3:06
- Total time: 13.51
- Swim time: 13.26
- Total seconds swimming is 806
- Divided by 6 = 134.3 seconds = 2:14.3 average per 100
- Cruise interval 1 = 2:19.3
- Cruise interval 2 = 2:24.3
- Cruse interval 3 = 2:29.3
Another variation, perhaps should be its own posting
Amy White posted about doing 6 x 100-yards on 8:00 for finding swimmers sprint threshold.
Personally, I hated T30 as a swimmer, but that's because your coach has to actively be paying attention to the entire group, and unfortunately, mine wasn't up to the challenge. It left me very bitter for years after. Basically, I was told that I was lying because I did more yards than the sectional level swimmer, who, like 90-percent of the team, didn't try on this set.
I was crushed, as I had essentially hit my mile pace. 2,525 yards; my goal was 2,500 yards. It was the last straw for me with that coach, and I switched club teams the following season. (Best mile time would have been 19:15 at that point).
The coach knocked it back 500 yards, and put me on intervals slower than I had the entire time he was there as a coach. Mind you, I cut over a minute in the 500 during this time.