Critical Velocity Calculator

Roughly your 5K pace divided by 0.9533 in the Tinman convention — for a 20:00 5K (6:26/mile) that is about 6:45/mile. CV reps are typically 3–10 minutes long (1000m–2000m for most high schoolers) with short recoveries.

Take two all-out efforts between about 2 and 30 minutes. CS is the slope: (distance2 − distance1) ÷ (time2 − time1) in meters per second. D′ is the intercept: distance1 − CS × time1. The further apart the two durations, the more reliable the fit.

D′ is your anaerobic distance reserve in meters — the finite distance you can cover above critical speed before exhaustion. A typical trained distance runner sits around 150–300m. Bigger D′ means a stronger kick; bigger CS means a higher sustainable cruising speed.

Close but not identical. CV/CS sits slightly faster than classic lactate threshold — between threshold and 10K effort for most runners. Tinman-style CV reps target that zone to build aerobic power without the cost of VO2max sessions.

The linear distance-time model assumes the effort is long enough that pure sprint mechanics don't dominate and short enough that fueling, thermoregulation, and durability don't. Outside roughly 2–30 minutes the line bends, so predictions (like a marathon from CS) become unreliable.

If you have two honest all-out efforts at different durations, the two-point model is personalized and more precise. If you only have one recent 5K, the Tinman estimate is a solid default — the two usually land within a few seconds per mile of each other.