VO2 Max Calculator

VDOT, developed by Dr. Jack Daniels, is a "pseudo VO2 max" that reflects your running economy alongside aerobic capacity. A lab test measures your body's maximum oxygen uptake in ml/kg/min during exhaustive exercise. However, two runners with identical lab VO2 max values can have different race times due to variations in running economy—how efficiently they convert oxygen into forward motion. VDOT captures this by working backward from race performance, making it more practical for predicting race times and setting training paces. Think of lab VO2 max as your engine size, while VDOT represents your actual miles per gallon.

Research shows VO2 max can improve 15-25% with consistent endurance training, though individual responses vary significantly. The HERITAGE Family Study found some people improved over 40% while others showed minimal gains despite identical training. Genetics determines roughly 50% of your baseline VO2 max and trainability. Most athletes reach 90% of their genetic potential within 2-3 years of serious training. However, performance can continue improving beyond VO2 max plateaus through better running economy, lactate threshold, and race strategy. Focus on consistent training rather than chasing a specific number.

Running economy—the oxygen cost of running at a given pace—explains this paradox. Frank Shorter won Olympic gold with a VO2 max of 71 ml/kg/min, while some less successful runners tested above 80. Research by Daniels showed that economy can vary 30% among runners with similar VO2 max values. Factors affecting economy include biomechanics, muscle fiber composition, tendon stiffness, and years of training adaptation. Additionally, lactate threshold (the percentage of VO2 max sustainable for extended periods) matters enormously. Elite marathoners often sustain 85-90% of VO2 max, while recreational runners may only manage 75-80%.

VO2 max declines approximately 10% per decade after age 30 in sedentary individuals, primarily due to decreased maximum heart rate and muscle mass. However, research published in the Journal of Applied Physiology shows masters athletes who maintain high training volumes experience only 5-7% decline per decade. A landmark study of lifelong runners found 70-year-olds with VO2 max values comparable to sedentary 20-year-olds. High-intensity interval training appears particularly effective at preserving aerobic capacity. While you cannot stop the decline entirely, consistent training can keep your biological age 15-20 years younger than your chronological age.

Different race distances test different physiological systems, revealing your training strengths and weaknesses. A higher VDOT from 5K suggests strong aerobic power but potentially underdeveloped endurance. A higher VDOT from the marathon indicates excellent economy and fatigue resistance but possibly untapped speed. According to Daniels' Running Formula, well-rounded training should produce consistent VDOT across distances within 1-2 points. Significant discrepancies guide training focus: if your 5K VDOT exceeds your marathon VDOT by more than 3 points, prioritize long runs and tempo work.

Running-based VDOT estimates correlate strongly with lab VO2 max (r=0.85-0.91 in validation studies) but measure something functionally different. Lab tests can overestimate performance potential by ignoring running economy, while VDOT can underestimate raw aerobic capacity if you race conservatively or in poor conditions. For training purposes, VDOT is often more useful—it directly predicts appropriate training paces without requiring expensive lab access. The estimate is most accurate from races of 10-15 minutes duration (roughly 3K-5K) run on flat courses in cool conditions.