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.

Your VDOT

37.1

Beginner+

Developing runner

3085

Race Predictions

5K25:00
10K52:07
Half Marathon1:55:00
Marathon3:59:47
Your Training Paces

Easy (E)

Recovery runs, long runs, warm-up/cool-down

10:52 - 10:04/mi

6:45 - 6:15/km

Marathon (M)

Race-specific endurance work

8:41 - 8:17/mi

5:24 - 5:09/km

Threshold (T)

Tempo runs, cruise intervals (20-40 min)

7:53 - 7:34/mi

4:54 - 4:42/km

Interval (I)

VO2max intervals (3-5 min reps)

7:24 - 7:05/mi

4:36 - 4:24/km

Repetition (R)

Speed work, strides (200-400m)

6:55 - 6:36/mi

4:18 - 4:06/km

Training Distribution

For optimal development, run 70-80% of your weekly mileage at Easy pace. The remaining 20-30% should include quality workouts at Threshold, Interval, and Repetition paces.

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
Share & Embed

Share this tool with your training group or embed it on your coaching website.

<iframe src="https://www.42cal.com/tools/training-paces?embed=true" title="Training Pace Zones by 42Cal" width="100%" height="800" style="border:1px solid #e5e7eb;border-radius:12px;"></iframe>
Open full-page tool

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

Related Tools

    Training Pace Zones Calculator | VDOT Running Paces | 42Cal