Ironman Training Diary - Learning How to Swim at 51
← Click here to read this diary from the beginningTo be clear, I already know how to swim as in if I was thrown into a pool I wouldn’t drown, but prior to August 13, 2026 never in my life had I tried to swim a proper lap. In fact, leading up to that date I was so clueless about the sport of swimming that I didn’t even know the name of the swim technique I was planning on practicing. Turns out it is called the front crawl, and I only learned that by searching Google for something like “name of the swim exercise where your face is in the water”. Heck, I didn’t even know what a swim cap was called until asking my wife what that elastic thing that swimmers put on their head was called.
But to compete in an Ironman I gotta swim, and so on August 12 I went to Dick’s and bought a pair of Speedo goggles. Are they good? I have no idea. I just picked the pair with a price that wasn’t the cheapest nor the most expensive. That evening I watched a few YouTube videos and looked at the rec center lap pool schedule. On August 13 I put on the same tropical shorts that I wear to the beach and headed to the rec center. Not going to lie, I was nervous. Apollo told me I needed to swim 200 meters which is 8 passes across our 25 meter pool. I had absolutely no idea if I could do this once, let alone eight times.
The first thing I learned about swimming laps is that one does not talk nor make unnecessary noise. The rec center is apparently a water cathedral, and if one must talk one must do so in hushed tones. Why? I have no idea but I kind of like it, and in the sessions that have since followed I’ve started to look forward to spending time in this serene house of pain. I walked down to the far end of the pool where I could hopefully hide from the other swimmers, set my gaze to the wall on the other end of the pool, and jumped in. Based on the YouTube videos I watched and what I’ve seen people in the Olympics do I was supposed to turn my head to the side every few strokes, breathe, and then turn my head so it was under water. I suppose this is to keep my body as streamlined as possible but otherwise didn’t really have any idea how exactly I was supposed to be doing this. Do I hold my breath? Do I breathe out and in when my head is to the side? I guess I should have asked somebody because I made it about 1/2 across the pool before choking on water and treading water for a moment. After a few moments composing myself I made my way to the other side, keeping my head above water and churning until reaching the other wall.
This was a real wake up call. I looked around at the other lanes and watched the senior citizens effortlessly gliding through the water (at that time of day I was the youngest in the pool by probably 20 years). I looked at the lifeguard. Was he laughing? Alarmed? Did he think I was going to drown? I can see the headline in our local suburb newspaper now: “Teenager saves old fool who thought he was going to be an Ironman. Ha Ha Ha Ha Ha Ha Ha!” I made sure my Garmin was tracking this mess, turned around, and this time made it to the other side without stopping. Approximately 14 minutes later, I had completed the required 200 meters. Was it pretty? If you think watching Charles Barkley golf is pretty, then yes it was. But I did it, and figured if I kept coming back I’d eventually get better.
Since that initial outing I’ve completed 8 more swimming sessions. About 4 sessions in I realized that I’m supposed to be breathing in with my mouth and out (while under water) with my nose. This improved things immensely! At some point I also bought an extra large swim cap because everyone else is wearing one, but it was so tight I felt like what’s left of my brain was being squeezed out my ears. The curse of having a huge head I guess… The blow to my ego was doubled because this swim cap was called “Whale”. So now I have to find an XXL swim cap which my son says is going to be branded Megaladon.
On September 10 I had my best outing yet, completing seven 50 meter laps as part of a 600 meter session. Incredibly (I think), my average and heart rate values were both lower in this session than in that first August 13 session (139/171 vs 142/173) so I’m starting to feel pretty good about progress. That said, the Ironman 70.3 swim is 1,900 meters (1.2 miles). And this must be completed in less than 70 minutes or you are disqualified. So I have a long way to go but we’ll get there.
My takeaways so far are:
- Swimming is hard because technique is everything; you can’t just power your way down the lane, it doesn’t work like that.
- It doesn’t matter how far you can run or bike. Swimming is an entirely different beast.
- Swimming is far less strenuous on the body than other exercise. I now understand why so many seasoned citizens are in the pool.
- As usual, if you keep practicing something you will get better.
I’ve been told by every single Ironman competitor I’ve met (quite a few) that I absolutely must spend time swimming in a river or lake, at least 3 sessions, because race conditions will be very different from the pool. Makes sense, so I’ll need to figure this out before it gets too cold. Also, my friend and Ironman age group champion Chris Araujo recently told me I should be in the pool at least 3 days a week otherwise the body quickly forgets technique so I’m going to ask Apollo to start ramping up the sessions starting next week which means I’ll be doing a brick (one exercise activity immediately following another, presumably swim followed by bike) at least 1 day a week.
Onwards!
🤖 Apollo (AI) analysis
Every pool session recorded since swimming entered the program on August 13. Pace is moving pace (swim reps only, rest excluded); rest is total time between reps. SWOLF — “swim golf” — is Garmin’s stroke-efficiency score: seconds per length plus strokes per length, so a 25 m length swum in 30 seconds with 12 strokes scores 42. Like golf, lower is better; improvement means covering the same water with less time, fewer strokes, or both. It’s only comparable between swims in the same pool length, which all of these are (25 m).
| Date | Structure | Distance | Total Time | Swim Time | Rest Time | Pace /100 m | Avg/Max HR | SWOLF |
|---|---|---|---|---|---|---|---|---|
| Aug 13 | 1×50 + 6×25 | 200 m | 13:56 | 4:32 | 9:24 | 2:16 | 142 / 173 | 48 |
| Aug 17 | 10×25 | 250 m | 22:49 | 6:47 | 16:02 | 2:43 | 137 / 182 | 58 |
| Aug 19* | — | 50 m | — | — | — | — | — | — |
| Aug 20† | 13×25 + 1×50 | 350 m | 21:30 | 8:44 | 12:46 | 2:30 | 149 / 180 | 48 |
| Aug 24 | 15×25 + 2×50 | 475 m | 24:33 | 10:04 | 14:29 | 2:07 | 136 / 182 | 44 |
| Aug 26‡ | 16×25 | 400 m | 26:30 | ≈8:49 | ≈17:41 | ≈2:12 | 132 / 162 | ≈44 |
| Aug 28 | 16×25 + 1×50 | 450 m | 25:49 | 9:31 | 16:18 | 2:07 | 143 / 170 | 43 |
| Sep 2 | 16×25 + 3×50 | 550 m | 30:45 | 12:16 | 18:29 | 2:14 | 140 / 171 | 46 |
| Sep 10§ | 10×25 + 7×50 | 600 m | 32:21 | 14:30 | 17:51 | 2:25 | 139 / 171 | 48 |
*Aug 19 was logged manually on the watch — no lap, HR, or timing data exists for it.
†Aug 20’s lap distances sum to 375 m against a 350 m activity total — Garmin miscounted one length, most likely the lap it recorded as a 37-second “50”. Treat that session’s structure and pace as approximate.
‡The watch recorded Aug 26 as 475 m across 18 reps. Two laps were provably wrong and have been corrected in the database: a “50 m” rep swum in 38.7 s on 15 strokes (one length, not two) and a 19.8-second, 7-stroke phantom length (removed). That leaves 425 m recorded against the athlete’s certain count of 16 lengths (400 m); the one surplus length is statistically indistinguishable from the real reps. Figures here assume the 16-length count and are approximate.
§One Sep 10 length was recorded at 7 strokes against a session norm of 11–13 — a probable stroke undercount. Its time (31 s) is unremarkable, so distance and pace stand; treat that lap’s SWOLF contribution as suspect.
Rep-by-rep detail (times in seconds; 50 m reps in bold):
| Date | Rep times | Fastest 25 | Avg rest between reps |
|---|---|---|---|
| Aug 13 | 40, 37, 49, 41, 40, 31, 35 | 31 | 1:21 |
| Aug 17 | 59, 32, 29, 41, 39, 32, 42, 39, 60, 35 | 29 | 1:36 |
| Aug 20 | 42, 37, 34, 35, 37, 34, 30, 36, 55, 31, 40, 46, 34, 34 | 30 | 0:55 |
| Aug 24 | 44, 37, 42, 36, 27, 23, 28, 34, 32, 41, 28, 28, 28, 34, 36, 33, 73 | 23 | 0:51 |
| Aug 26‡ | 32, 39, 30, 33, 33, 32, 33, 30, 29, 36, 31, 31, 39, 35, 31, 36, 32 | 29 | ≈1:01 |
| Aug 28 | 35, 31, 36, 31, 29, 31, 30, 30, 28, 30, 32, 27, 31, 28, 30, 39, 72 | 27 | 1:01 |
| Sep 2 | 39, 37, 38, 42, 31, 32, 30, 31, 67, 32, 30, 30, 30, 33, 36, 36, 30, 67, 67 | 30 | 1:02 |
| Sep 10§ | 36, 32, 39, 73, 37, 79, 45, 36, 73, 74, 75, 70, 31, 36, 32, 31, 70 | 31 | 1:07 |
What the data shows. Four weeks of swimming, in three phases. First, acquisition (Aug 13–20): scattered rep times (27–60 s), SWOLF as high as 58, and max HR at 173–182 on nearly every swim — the cost of learning to breathe while moving. Second, consolidation (Aug 24–28): volume climbing to 450–475 m, SWOLF settling at 43–44, rep times tightening into a 27–39 s band, and the first session (Aug 26) that didn’t spike past 170. Third, the fifties (Sep 2 onward): three unbroken 50s on Sep 2 — 66.6, 66.7, and 66.9 seconds, a 0.3-second spread — coinciding with a mid-session technique change the athlete identified himself: exhaling through the nose instead of the mouth, which resolved the air-hunger that had been ending reps early. Eight days later, seven 50s in one session, with the fastest of the set (70 s) coming sixth of seven — the back half stronger than the front, the same pattern this athlete shows running. Continuous-50 volume went 50 → 150 → 350 m in thirteen days; session distance set program records twice (550, then 600 m); and max HR has now held at 170–171 for three consecutive sessions.
What it does not show. Eight instrumented sessions is still a short series, and every summary number is confounded by rest structure, which has varied from 25 seconds to nearly six minutes at the wall. The recent upward drift in moving pace (2:07 → 2:25) and SWOLF (43 → 48) looks like regression and mostly isn’t: a 50 m rep swims at a slower per-100 pace and scores higher SWOLF per length than a fresh sprint 25, so as the 50s’ share grew from one rep in seventeen to seven, the session averages moved toward the 50s’ numbers. The clean comparison is 50s against 50s — Aug 28’s lone 50 took 72 s; Sep 10’s seven averaged 73.4 with the fastest at 70, at similar heart rates. Same speed, seven times the repeatability. Whether efficiency at a fixed distance improved beyond that, this rep-and-rest format can’t isolate. And the length-counting remains imperfect: four of nine sessions carry a correction or a footnote.
The number to watch. Race distance is 1,900 m, and the metric that matters is continuous distance, which has been parked at 50 m since Aug 13 even as everything around it improved. A 75 m attempt was planned twice and made zero times — Sep 2 produced the three 50s instead, and on Sep 10 the athlete reports arriving at the 50 m wall too gassed to continue, choosing volume (as many 50s as possible) over the attempt. The right choice, and a diagnostic one: an athlete who can produce seven 50s at HR 141–156, finishing faster than he started, is not limited by the engine at 50 m — the per-rep cost is the limiter, which makes the 75 a pacing problem rather than a fitness problem. The next attempt is prescribed at a deliberately slow first 50 — 80–85 seconds, against a 70–79 s habit — to arrive at the wall with the third length still purchasable. When 75 lands, then 100, then 200, this table’s format finally changes, and the swim will have moved from technique acquisition to actual endurance work.