Does training for a marathon make you healthier?
I have four months to train for the BYD Singapore Marathon, a five-hour target, a Garmin full of estimates, and Dr. Varun Reddy keeping the science straight. We are tracking what happens to my fitness, muscle, strength, recovery, and health—and publishing the useful parts, including the mistakes.
Where the training actually stands
Day 4 of Week 1. Nothing has been run yet under the current plan, so this strip mostly shows zeros and a target — that's what day one of a seventeen-week plan looks like.
What's been written so far
The plan starts Monday — and it already changed once
Before I ran a single step, I re-read my own training plan next to the numbers a physiologist would use, and didn't love what I saw. What changed, and why the doctor review isn't even the reason.
Why I'm doing this
A marathon has a finish line. Health doesn't. This is the premise, the five-hour number, and why I'm treating my own body as the data set.
Why a marathon needs a second opinion
I can put together a training plan that looks correct on paper. I can't tell you what it does to a 40-year-old's blood pressure. That gap is why Dr. Varun Reddy is involved in this project.
What's actually being measured
The athletic goal is simple: 42.2 km in 5:00. The health outcome is not. VO₂ max might improve. I might lose muscle. Some numbers may do nothing interesting at all. Those are all valid results. The job is to measure carefully, adapt the plan when reality intervenes, and resist turning one person's story into a universal prescription.
The plan is already a v2
Current plan: Version 2, effective 10 Aug 2026 (Week 1). Latest revision: v1 → v2, made three days before training started. Short reason: the original weekly-mileage ramp broke the standard 10%-per-week guideline badly enough that I didn't trust it, so I smoothed it before Dr. Reddy's formal review even began.
What I thought → what Dr. Reddy thought → what we did → what happened
The recurring framework for when the author and Dr. Reddy materially disagree. Here's the first instance — still short one voice, because his review of the plan hasn't happened yet.
What VO₂ max is—and what my watch is about to guess
My Garmin will start estimating VO₂ max the moment it has enough run data, using an algorithm, not a lab. Before those numbers show up on the dashboard, it's worth knowing what they actually mean — and what they don't.