What Is VDOT?
New to running? Start with the Beginner's Running Guide first. VDOT training works best once you have a running base.
VDOT is a running fitness indicator created by Dr. Jack Daniels (yes, that's his real name — he's a legendary running coach, not a whiskey brand).
The concept is simple. Enter your race result, get a single number representing your current ability, and receive exact training paces matched to that ability.
A runner who finishes 5K in 25 minutes has a VDOT of roughly 38. Their proper easy pace? Around 6:30-7:10/km. Most runners would guess they should run easy at 6:00/km or faster. VDOT says otherwise — and the science backs it up.
Finding Your VDOT
The most accurate input is a recent race time. 10K to half marathon distances give the best results. 5K works too.
Calculate yours with the TT Runner VDOT Calculator.
Automatic VDOT Tracking in TT Runner
The app estimates your VDOT from every run and gives training feedback automatically. No races required. Just run consistently and your VDOT stays updated.
The 5 Training Paces
VDOT defines 5 training zones. Each has a specific purpose. Mixing them properly is what makes training effective.
E Easy
This should be 80% of your total training. It's the most important workout, not the least.
Purpose: cardiovascular development, capillary growth, recovery. If you're thinking "this feels too slow," you're probably at the right pace. You should be able to hold a conversation comfortably.
The #1 training mistake is running easy days too fast. This prevents recovery, and when interval day comes, you're already fatigued.
M Marathon
Your marathon goal pace. Useful for building long-distance aerobic capacity even if you're not training for a marathon.
Slightly faster than easy. You can still talk, but long sentences become difficult.
T Threshold / Tempo
The pace where lactate starts accumulating rapidly. The benchmark: "Hard, but I could hold this for about 20 minutes."
Training at this pace raises your lactate threshold — you can sustain faster paces for longer. This is the workout that most directly improves race times.
Once per week, 20-40 minutes. Slightly slower than your 5K-10K race pace.
I Interval
High-intensity work targeting VO2max. Run hard for 3-5 minutes, rest for equal time, repeat.
Conversation is impossible at this effort. You're breathing hard, but your form shouldn't collapse.
Once per week. Total hard running shouldn't exceed 20 minutes. Example: 1000m × 5 with 3-minute recovery jogs.
R Repetition
Short, fast efforts for running economy and speed development. 200-400m at near-max effort with full recovery between reps.
Faster than I pace, but shorter distances mean less total stress.
Sample Weekly Plan (VDOT 38)
| Day | Workout | Pace | Duration |
|---|---|---|---|
| Mon | Easy run | 6:30-7:10/km | 40 min |
| Tue | Intervals | 4:50/km | 1000m × 4 (3 min recovery) |
| Wed | Rest | - | - |
| Thu | Tempo run | 5:25/km | 20 min |
| Fri | Easy run | 6:30-7:10/km | 30 min |
| Sat | Long run | 6:30-7:10/km | 60-80 min |
| Sun | Rest | - | - |
The principle: easy days genuinely easy, hard days genuinely hard. Running at medium effort every day is the least efficient way to train.
When Your VDOT Improves
Retest after 6-8 weeks. With proper training, expect a 1-2 point increase. When VDOT rises, recalculate all training paces.
Automatic Pace Adjustment in TT Runner
AI detects VDOT changes from your recent runs and adjusts recommended paces in real time. "Your easy run was too fast today." "Interval volume is high this week." Specific, actionable insights after each session.
Get Started
- Check your VDOT with the calculator
- Note your 5 training paces
- Run 4-5 times per week: 80% easy + 20% hard
- Retest after 6-8 weeks
AI Analyzes Every Run
Automatic VDOT tracking, training zone detection, weekly AI reports.
Just run — feedback follows.