Science-backed guides on periodization, training load, and race preparation.
Lactate threshold is the most trainable fitness variable in distance running. Learn what it actually is, how to estimate yours without a lab, and the three session types that raise it fastest.
Most marathon plans are written for a runner who doesn't exist. Adaptive training plans respond to what's actually happening in your body each week. Here's the difference, and why it matters for intermediate runners.
Jack Daniels' running formula is the most rigorously tested training system in endurance sport. Here's how it works, what the five training intensities do, and why it beats every generic plan.
Your watch gives you a VO2max estimate. Jack Daniels built VDOT to replace it. Here's why the two numbers differ, which one actually controls your training paces, and what to do when your watch gets it wrong.
If you've followed a marathon training plan and still underperformed, hit the wall, or ended up injured, the plan is more likely to blame than you are. Here's the structural reason why most training plans fail intermediate runners.
CTL, ATL, and TSB are the three numbers that tell you whether you're getting fitter, overtrained, or ready to race. Here's how they work and why they matter for marathon runners.
VDOT is the most practical measure of aerobic fitness for runners. Learn how Jack Daniels' formula translates your race time into exact training paces for every workout type.
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