Free instrument
VDOT calculator
Jack Daniels' single number for running fitness — a pseudo-VO₂max derived from what you actually raced, not what a watch guessed. It's the seed every Stridelab pace grows from.
Recent race distance
Finish time
Jack Daniels' single number for running fitness — a pseudo-VO₂max derived from what you actually raced, not what a watch guessed. It's the seed every Stridelab pace grows from.