Training for a triathlon

October 19, 2025

I’m training for a triathlon.

As a kid I was not a fan of swimming, and my hands are sensitive to cold water, so I mostly avoided it. For my whole adult life I’ve told myself “one day I’ll properly learn to swim”. I decided it was finally time to fulfill that promise I made.

Knowing that deadlines and tracking metrics are incredibly motivating for me, I signed up for a triathlon in June 2026 as a forcing function.

Here’s my progress so far:

Loading training data…

How do I track this data?

I save my workouts using a Polar HR10 sensor and the Strava app on my phone. I sync Strava activities into a Google Sheet via Google Apps Script. For now, I manually add swims to a separate tab in the same Google Sheet. The sheet publishes a public CSV; this dashboard fetches it on page load.

Process

I read all 3 triathlon books by Taren Gesell, which were the perfect minimum knowledge I needed to get into action. I highly recommend these books to get started.

Here’s the condensed version of the tips that have been most helpful to me as I progress:

[Swimming]

  • Focus on the weakest thing first: for me, that was swimming.
  • Spend a lot of time on breathing. The first several times I got into the pool, I noticed a tightness in my chest, a low-level anxiety when under the water, and a shortness of breath, even though I was breathing more.
    • The shortness of breath is not lack of oxygen, but rather too much CO2. I noticed a shift when I was able to start breathing out consistently. A useful primer was to train myself to hum whenever I was underwater - that way I was always breathing out.
  • At least at beginner level, the purpose of kicking is just to keep your legs from sinking and maintain body alignment. Almost all the propulsion comes from the arms!
  • Body alignment is key.
    • Looking straight down (rather than looking ahead) makes a big difference.

[Cycling]

  • The cycling is where the wheat is separated from the chaff. The difference between strong swimmers and slow swimmers isn’t large. But for cycling, there’s a big difference. So if you’re trying to be competitive, it makes sense to focus a lot of time on cycling.

[Running]

  • Running is the hardest on the joints and the easiest and shortest distance of the three. Also, improving cycling benefits running, but not so much the other way around.

Gear I bought

General

  • Trainiac Taren’s Swimming/Cyling/Running Foundations books
  • Smartwatch - Garmin Forerunner 255
  • Polar H10 Chest strap - I had this already, gives accurate HR data
  • Mottiv - Simple app (also by Taren) to plan my weekly workout schedule

Swimming

  • Prescription goggles - so I can see the bottom of the pool in HD
  • Swimcap
  • Speedos (ha!)
  • Face moisturizer (my face gets very dry after swimming in the chlorine)
  • Snorkel - Finis Swimmer’s Snorkel
  • Fins - TYR Crossblade 2

Cycling

  • Headband
  • I haven’t bought a bike yet, so I’m just training on a stationary bike at the gym for now

Running

  • Shoes

Other resources I found helpful:

  • Coming soon