Taj Krieger

Most cyclists understand the principle behind fat oxidation training: ride at lower intensities, fuel a greater proportion of energy from fat, reduce carbohydrate dependency. The reasoning is sound, and the physiological goal is legitimate. The issue is how that principle gets translated into practice. The most common approach — ride below some percentage of FTP, stay "aerobic," log the hours — is mechanistically incomplete. It assumes that fat oxidation is primarily a function of relative...

VO2max might be the most famous number in endurance sport — and one of the most misunderstood. It's on your Garmin, your Apple Watch, and probably somewhere in your fitness tracking app. But it rarely explains performance the way people think it does. It's the number endurance sport has centered fitness around for decades. But most people optimizing their training around it don't actually know what it measures, what limits it, or — more importantly — what it completely fails to capture. That...

You've been consistent. You're hitting your intervals. Your TSS is high, but your FTP hasn't moved in six months — maybe longer. Every eight weeks you run another ramp test, and the number sits there unchanged or even trending downwards. If you're wondering "why is my FTP not improving despite structured training", the answer almost certainly isn't that you need to work harder. It's that you're training without knowing what's actually limiting you. FTP might show you that  you've plateaued,...