Belgrade Marathon

Pre-filled with race data: 50K

Training Optimization

Training Pace Zones

Enter a recent race time to calculate your VDOT and get personalized training paces based on Jack Daniels' proven system.

Your Recent Race

Use a recent all-out effort from the last 4-6 weeks for best accuracy.

About VDOT

VDOT is a running fitness index developed by legendary coach Dr. Jack Daniels. It combines your aerobic capacity (VO₂max) and running economy into a single score.

Unlike raw VO₂max, VDOT is derived from actual race performance, making it a more practical measure of your current fitness.

Typical VDOT Ranges:

  • • 30-40: Beginner to intermediate
  • • 40-50: Recreational competitive
  • • 50-60: Competitive age-grouper
  • • 60-70: Advanced/sub-elite
  • • 70+: Elite
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How to use your training paces

  • Easy (E): Most of your running. Should feel comfortable—you could hold a conversation.
  • Marathon (M): Practice runs at goal marathon pace. Useful for race-specific long runs.
  • Threshold (T): "Comfortably hard." Tempo runs of 20-40 minutes or cruise intervals of 5-15 minutes.
  • Interval (I): Hard but controlled. 3-5 minute repeats with equal recovery. Builds VO₂max.
  • Repetition (R): Near all-out speed. 200-400m reps with full recovery. Improves running economy.

How to Use This Calculator

Enter a recent race distance and finish time to calculate your VDOT score and all five Jack Daniels training pace zones. For best results, use a race you ran at full effort within the last 6-8 weeks. The calculator generates personalized paces for Easy runs, Marathon tempo, Threshold (lactate turnpoint), Interval (VO2max), and Repetition (speed and economy) training. Each zone targets a specific physiological adaptation and should be used within its prescribed range for optimal training effect.

What Is VDOT?

VDOT is a measure of running fitness developed by exercise physiologist Jack Daniels. It represents a pseudo-VO2max value — your effective aerobic capacity as expressed in race performance. Unlike a lab-tested VO2max, VDOT accounts for running economy and lactate threshold, making it a more practical indicator of race fitness. A VDOT of 50 corresponds roughly to a 3:33 marathon or 19:36 5K. Each VDOT point represents about a 1-2% change in race performance. The five training zones derived from your VDOT ensure that each workout targets the right intensity for its intended physiological purpose — easy runs build aerobic base without excess stress, while interval sessions develop VO2max capacity.

Frequently Asked Questions

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