In a perfect world, you would have a swim lane to yourself, your coach ensuring that every stroke you made was directed towards improving your propulsion and streamline technique. Your training would always be focused towards continually improving your times until you achieved your swimming goal.
As with a lot of people though, this is isn’t reality. A lot of triathletes train on their own, managing to swim with groups and coaching clinics through the year, but a majority of the training and improvement they make comes from books and articles they have read and knowledge they have gained through trial and error. My trial and error has given me some clear indications on what not to do with swim training, and the following are my seven big mistakes I have made and I hope won’t hold anyone else back.
1. Not warming up
I thought if I swam as fast as I could from the start of the training session, it would set the tone for the rest of the session. My warm up now consists of close to one kilometre of swimming and drills to help elevate my core and muscle temperatures, and increase blood and oxygen flow to muscles, helping prepare for and get the most out of the tough workout ahead.
2. Just swimming laps, non-stop
I would just continuously swim laps. I would swim ten laps at a slow pace then ten laps at a faster pace with no break or changes. I was not preparing myself for the changes speed or intensity that I would need to get used to as part of a race.
3. Not timing my swims
I would just swim by feel, under the assumption that if I felt that I was swimming fast, then I was swimming fast. When I first started timing my swims, it was a big wake up call, and it was a big motivator to push my work rate harder. Not only was I swimming a lot slower than what I thought I was, I was not as consistent either.
4. Breathing only on one side
Breathing only to my left was easy and every second stroke gave me enough oxygen to keep swimming, but it also caused an imbalance in my stroke and allowed my left arm (non dominant arm) to remain weaker than my right.
5. Only swimming freestyle
I was racing freestyle so I trained freestyle. As with bilateral breathing, swimming different strokes is helping me remove any imbalance that I may have in my freestyle stroke and help improve my speed.
6. Not swimming in open water
I expected my pool swimming to simply translate directly into open water, but it did not prepare me for the cold, deep water, the thrashing and bumps of other swimmers around, and I had no idea how to swim through a choppy or wavy ocean.
7. Not changing my swim training sets
When I started to learn more about technique and drills to improve my technique, I would keep the same drills and sessions week after week. Although I was improving, I was not challenging myself through different sets, pacing different speed, increasing distance, etc.
Vince Sesto

Vince Sesto
Tri Swim Coach Ambassador
Vince works as an IT Engineer in Melbourne, Australia where he lives with his cat Tim Tam. He has been a runner for longer than he can remember. He competes in distance running races, open water swims and long course triathlons.