About Nico Run Lab
The calculators I use for my own sessions, and the guides that go with them.
The site
Eight calculators: max heart rate, heart rate zones, field tests, training paces, VO2 max, race times, pace and km to miles. Each result shows the formula behind it. The guides explain how to run the tests and what to do with the numbers. Gear reviews come later.
Who makes it
I’m Nicolas. I started running in February 2024: a bit over 1,000 km that first year, 1,780 in 2025, and these days around 35 km (22 miles) a week. Road in winter, trails the rest of the time. My half marathon PR is 1:37:40, and I’ve worn through about thirty pairs of shoes since I started.
The race that taught me the most is L’Arvor, a 35-mile run around the Gulf of Morbihan in Brittany. In 2025 I finished in 9:21 and walked a good part of the last 12 miles. I went back in 2026, kept things under control and finished in 7:52, with a rolled ankle at mile 27 thrown in. I also wrote the calculators.
Your data
There’s no account. The math runs in your browser and nothing you type is stored. The results are estimates, so read the health disclaimer before an all-out test.
Contact
Spotted a mistake or have a question? Email contact@nicorunlab.com.