The number one indicator of performance in runners isn't VO2max, it's vVO2max - the slowest speed at which you hit your VO2max. It combines the engine and the efficiency into one number. A study in PubMed put 17 trained runners through a 16k time trial and vVO2max explained the finishers 94% of the time, while VO2max only got 81%. The test is simple enough to do this weekend. Flat track, fresh legs, set a timer for 5 minutes and run it all out at an even effort. Whatever your average pace is for those 5 minutes, that's your number. And 5 isn't a round number somebody picked - a guy named Berthon worked backwards from world record data in 1997 and calculated it, then an independent group ran the math again in 2024 and landed on 4.97 minutes. I ran my own 3200 test last week 18 seconds negative split... which by this test's own rule means I paced it instead of maxing it, so my number reads slow. Get to run it again 🙃 FYI: your first one will probably read slow too. It's a pacing skill before it's a fitness measurement. The prompt digs through your last 6 months, finds any run that could reasonably be a test, and if there isn't one it hands you the test and builds the plan off your result. Full guide and prompt here: vVo2 Max Prompt Here Fun one to run this weekend if anyone's got a track nearby! Kevin