VDOT calculator

What VDOT is

VDOT is a running fitness score developed by coach Jack Daniels and mathematician Jimmy Gilbert. It is worked out from a race result, not from a lab test, and it combines your aerobic capacity with how economically you run. Two runners with the same VDOT can expect similar race times at every distance, whatever their lab VO2max.

The value of VDOT is that one number gives you both predicted race times and the paces to train at. That makes it one of the most practical tools in running. This calculator is part of the free LeCoach running calculators.

How VDOT is calculated

The model has two parts. First, the oxygen cost of running at a given speed:

VO2 = −4.60 + 0.182258 × v + 0.000104 × v² (v in metres per minute)

Second, the fraction of your maximum you can sustain for the duration of the race:

% max = 0.8 + 0.1894393 × e^(−0.012778 × t) + 0.2989558 × e^(−0.1932605 × t) (t in minutes)

VDOT = VO2 ÷ % max

Your training paces

From your VDOT, the calculator derives five training intensities. These are the paces for a VDOT of 40 (10K in 50:00) and 50 (5K in 19:57):

How to use them in a week:

• Easy pace for most of your running, typically 75 to 80 % of weekly volume.
• Threshold once a week: for example 4 × 1 mile at T pace with 1 minute rest, or 20 minutes continuous.
• Intervals once a week in a build phase: for example 5 × 1,000 m at I pace with jog recovery of about the same time.
• Repetitions as short, fast, fully recovered efforts: for example 8 × 200 m at R pace with 200 m jog.
• Marathon pace in long runs when preparing for a marathon.

Equivalent race times

Your VDOT also predicts race times at other distances. A VDOT of 50 corresponds to about 19:56 for 5K, 41:20 for 10K, 1:31:31 for the half marathon and 3:10:40 for the marathon. Those predictions assume you have trained for each distance; the race time predictor compares them with the Riegel formula.

Common mistakes

• Using a goal time instead of a real result. Train at the paces of your current fitness, not the fitness you hope to have. Train at your goal paces and you will be overreaching within weeks.
• Running easy runs too fast. The easy range exists for a reason: it builds aerobic fitness while leaving energy for quality sessions. Most runners run easy days too hard.
• Updating VDOT every week. Update it after a race or a solid time trial, roughly every 4 to 8 weeks.
• Applying road paces on trails or hills. Use effort and heart rate there. Set your heart rate zones with the heart rate zone calculator; the LTHR method works for running too if you test while running.
• Using a race run in heat or wind. It underestimates your VDOT. Use your best recent result in good conditions.

When to adjust your paces

• Heat and humidity: slow every pace, especially threshold and intervals. Run by effort.
• Altitude: above 1,500 m, slow I and T paces; R pace is less affected.
• After illness or a break: drop your VDOT by a few points and rebuild.
• Late in a long run: marathon pace will feel harder at the end. That is the point, as long as form holds.

LeCoach writes your running workouts with paces from your own threshold pace, and you can ask the coach to adjust a session when the weather or your recovery says so.