Week 2 of 20. The running speed is showing up. The aerobic base work isn’t.
Here’s the honest breakdown.
The Week
Monday — 5×1km intervals on the treadmill at 4:25/km. Consistent across all five reps. Then a secondary 4.5km run with the kids at the track in the evening. Two runs, solid day.
Tuesday — Nothing. Felt off, stayed up too late the night before, body said no. This is the first fully missed day of the plan and it happened in Week 2. Noted.
Wednesday — 10×400m at the track with my wife Emma. Splits: 1:34, 1:42, 1:39, 1:41, 1:43, 1:44, 1:42, 1:40, 1:41, 1:41. Average 4:12/km. Best rep: 3:55/km.
That 3:55/km number is significant. My Hyrox race target is 4:00/km sustained across eight runs. In Week 2 of training I’m already running faster than race pace in intervals. The speed ceiling is high.
Thursday — Titan Up lifting. Bulgarian split squats at 70lbs, side lunges at 53lbs. Then 30 minutes on the bike erg — but at damper 5, which was too high. Spent the entire session in Zone 0-1 because the legs built up lactic acid before the cardiovascular system could engage. Discovered that Zone 2 on the bike requires damper 2-3 at high cadence (85-95rpm), not heavy resistance. Key fix going forward.
Friday — Sofit class. SkiErg, running, burpees, rowing, bike circuits. Average HR 154, max 178. Zone 4+5 combined: 28 minutes out of 39. Another high intensity group session where Zone 2 base work didn’t happen.
Saturday — Emma’s birthday bootcamp at Titan Up. Bulgarian split squats with 70lbs, side lunges with 53lbs. Back tweaked here. Lower back soreness that carried into Sunday.
Sunday BFT — Full sim, 5 minutes per station format. Total time 1:21:00 (not directly comparable to race time due to the format). Average HR 149, max 173. Zone 4 time: 42 minutes. HR recovery: -74 bpm — elite rating again.
The Problem I Keep Creating
Look at the weekly HR data and a pattern is obvious: almost everything I’m doing is Zone 4-5. Group classes, Sofit circuits, BFT sims — they’re all high intensity. The aerobic base building Zone 2 run — the slow, nasal breathing, embarrassingly easy session — has not happened as a standalone workout in two weeks of training.
This is the core Hyrox training mistake that most beginners make. They train hard. They train often. They just never train easy enough to build the aerobic floor that makes sustained race pace possible.
The 80/20 rule in endurance training is real: 80% of your running volume should be easy (Zone 2), 20% should be hard (intervals, tempo). I’m currently running about 0% Zone 2 and 100% high intensity. That has to change.
The other issue: the back tweak from Saturday’s bootcamp. Two potential nerve issues now — a pre-existing leg nerve impingement limiting squat depth, and now a lower back tweak from heavy split squats the day before a full Hyrox sim. The body is talking. I need to listen.
What Week 2 Showed Me
The running speed is ahead of schedule. The aerobic base is behind schedule. The body needs more recovery discipline.
If you’re building a Hyrox training plan, here’s the tip from my Week 2: protect your easy runs like they’re the most important sessions of the week. Because they are. Group classes feel more productive. They’re not. The Zone 2 run is the foundation. Without it, you’re building speed on sand.
Week 3 the Zone 2 run happens. No negotiating.
— Austin