Will Thames

swim, bike, run, tech

Interesting Results From a 2500m Swim

I can’t count lengths very well - getting better as my swimming improves, but I thought I was at 96 lengths when I was only at 94, for example. For this reason, I have a sportcount ring, which lets me click a button at the end of every length, and times it too, storing up to 99 lap times. Annoyingly, the only way to transfer the times is to click through the laps one at a time, and then type them into a spreadsheet - it’s not perfect, that’s for sure! What it does provide is a source of data for analysis though!

Anyway, my post is to highlight a few observations from session 9, level 2 - the 2500m swim. I tried this first on Monday, but got interrupted 20 mins in by an aquafit class roping off the shallow end - I should have checked the classes! However, I wasn’t going to give in, this was a matter of willpower and discipline - I’ve never swum further than 30mins in the pool uninterrupted (the most I managed was 1350m) or more than 1500m in open water. And so on Wednesday I returned to try the 100 lengths again.

98 lengths took me 1h04, including a quick check at what I thought was 96 to check I wasn’t at 98 (I was always going to stop the watch at 98 as I wasn’t sure what would happen if I hit 100), so that was 94 laps uninterrupted, and a total swim of 100 laps.

Comparing the swim against a 30 min time trial, I didn’t swim more than 46 laps (1150m) in any 30 minute period, but those 46 laps ranged from 29:44 (laps 52 to 97) to 30:46 (laps 7 to 52) across the whole swim. Interesting that the quickest 30 minute periods were towards the end!

I remember feeling at the time that I was swimming at my best around when my lap numbers were in the seventies. My feel for the water was better, my catch and pull felt strong, I was really in the zone. Looking at the quickest sets of 10 lengths, it was 71-80, at 6:13/250m. Conversely my slowest (other than around the 50 length mark where I readjusted my goggles a few times) was 7-16.

I think the thing for me to take away from this is that my technique improves with warm up, and that pacing is critical - lap 1 was 31 seconds, lap 2 was 34 seconds, and yet laps 1-10 (38.1s per lap) were still slower than 71-80 (37.3s per lap), by which time I’d settled down into a great rhythm.