52at52 km/week

Same 52. A new reason to keep moving.

Season two · Starts on Nov 7, 2026

Season 1 taught me something that matters more than any finish time: I would not have stayed nearly as active without the challenge. Giving myself a commitment, and a reason to show up every week, made a real difference. When those 52 half marathons were done, I wanted to keep that going.

But continuing did not have to mean repeating. I wanted a new challenge, not a rerun of the same year.

Bringing the bike back

I love riding my bike. During Season 1, running took priority so often that I really missed cycling. Season 2 makes room for both: runs, rides, or a mix of the two, spread over as many activities and days as the week allows.

The weekly target stays at 52 credited kilometers, from Saturday to Friday. Because I generally find cycling easier per kilometer than running, I am giving bike distance a 2:1 conversion: two kilometers ridden count as one kilometer toward the challenge.

Run km + (ride km ÷ 2) ≥ 52

My week Actual distance Credited toward the goal
Running only 52 km running 52 km
Cycling only 104 km cycling 52 km
A bit of both 26 km running + 52 km cycling 52 km
Another mix 40 km running + 24 km cycling 52 km

The activity data will still show the distance I actually covered. The conversion only applies to the weekly challenge score, not to pace, speed, elevation or equipment mileage. A missed week stays missed; there is no carrying extra kilometers into another week.

Why not 53 at 53?

A few friends asked why I am keeping the 52 when I am turning 53. My answer: I have created a brand now, and I want to stick to it! Besides, a year gives me 52 full weeks to work with. That is a convenient excuse, and I am taking it. LoL.

The thinking behind 2:1

This is a practical rule for my challenge, not a claim that every 104 km ride is physiologically identical to a 52 km run. In my own training, long runs and harder rides have often averaged around 155 bpm. That is useful personal context, but I am not treating a matching heart rate as proof of identical energy expenditure.

The 2024 Adult Compendium of Physical Activities assigns different MET values to activities and intensities; these are useful comparisons, not precise calorie measurements for an individual (Herrmann et al., 2024). Its cycling table classifies riding at 14–15.9 mph, approximately 23–26 km/h, as vigorous effort, which puts my roughly 25 km/h riding pace in a different category from a casual cruise (2024 Compendium activity table).

Real-world cycling power also depends on aerodynamic drag, air velocity, gradients and rolling resistance, not simply the number of kilometers covered (Martin et al., 1998). That is another reason I want a consistent challenge rule rather than pretending every route has the same energy cost.

Scott and colleagues also showed why comparing running and cycling involves more than a single oxygen-uptake measurement: in their study, combined estimates of aerobic and anaerobic expenditure were similar for work-matched, one-minute bouts of cycling and uphill running (Scott et al., 2006). Those were brief laboratory efforts, not long outdoor sessions, and the study does not establish a 2:1 distance conversion (Scott et al., 2006).

So I am using the research as context, not as a certificate of exact equivalence. Two-to-one is my simple, consistent way to make room for the bike while keeping the weekly commitment meaningful. The goal is the same as before: keep moving, keep showing up, and enjoy the journey.

Further reading

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