56. Engineering
The first week after the race was mostly rest, and I let myself sink into it without guilt. I slept in, walked instead of ran, and gave my body the time to absorb what it had done. By the second week I was back at it, almost at full power, and what surprised me was not really the speed of the return, though I feel genuinely blessed for how quickly the physiology bounced back, but rather what the quiet made room for (more building, more reading, more family time).
I picked up a niggle in my left knee. Nothing dramatic, but enough to force a pause and some honesty. I have been doing more bodyweight strength work, heavy on calf raises, because I suspect the issue is muscle imbalance rather than the knee itself. It is the kind of small maintenance work that is easy to skip when you are charging toward a race, and impossible to ignore when the race is done.
But recovery also gave me time to look at my systems. Almost a year ago I started building PeakForm, a private dashboard to track training, physiology, and nutrition. I was tired of the friction and cost of TrainingPeaks, and I wanted something that answered to me. With the recent advances in agentic coding, I have now freed myself from it entirely (bye bye subscription). I built my own calendar, connected the data, and can send workouts straight to my Garmin. It is not perfect, but it is mine, and it does exactly what I need.
The broader insight kept expanding. Software is not a moat anymore. If you need something, you can build it. The real frontier is the data layer: collecting it, cleaning it, structuring it so it becomes useful. The interface is almost an afterthought once the data is yours.
That thought led me to my health tracking stack. I have always rated HRV4Training as the best way to collect resting heart rate and HRV on waking. But Coach Matthew arrived, and inconsistent wake-up times made that discipline nearly impossible. After a year with Oura, killed by short battery life, I moved to Whoop. It collects data decently, but if, like me, you think the scores are largely rubbish, the subscription becomes insultingly expensive.
Then I was reading the Tim Cook biography, specifically the chapters about outsourcing to China and how Apple re-engineered manufacturing by breaking down what was actually hard versus what was merely assumed to be hard. The same thought hit me about hardware. Why am I paying a premium for sensors I can source myself?
I opened AliExpress. For £17, shipping included, I bought an R02 smart ring. It is a bare-bones wearable, Bluetooth 5.0, IP68 waterproof, no display, no subscription. It captures heart rate, blood oxygen, sleep hours, and movement. There are over twenty sport modes built in, but I only care about the raw signal. The idea is to pull the data via Bluetooth into my own stack, clean it, and own the layer entirely. If it makes it to London, and AliExpress logistics are a probability distribution all their own, it becomes the next experiment.
I used to think building hardware was a different league. It is not. The sensors are commoditised, the protocols are standard, and the gap between consumer product and component is narrowing fast. The real skill is not buying the ring. It is writing the pipeline that turns its raw output into something actionable. I’m sure this will be type 2 fun.
Carve Out
I finished The Martian this week. Andy Weir's Mark Watney is a portrait of pure engineering ingenuity, solving one impossible problem after another with physics, chemistry, and an almost arrogant refusal to accept that a situation is unfixable. The book resonated because it is exactly the mindset required to rebuild your own stack: ignore the marketing, interrogate the tech, and build your way out.