Millions of Garmin workouts reveal their biggest predictor of VO2 max.

Garmin has released its annual running and cycling data reports, drawn from Garmin Connect activity logs across 2025. The data covers millions of users worldwide. The headline finding is one that exercise science has long supported: athletes who train more tend to record higher VO2 max values. At this scale, the relationship is consistent across every mileage band.

What the data shows

Among cyclists, the association between weekly mileage and VO2 max is consistent throughout. Riders averaging 0-20 miles per week recorded an average VO2 max of 49. Those averaging 200 miles or more recorded 64. The progression is steady: 20-40 miles per week returned 51, 40-60 returned 53, 60-80 returned 54, continuing upward to the 180-200 band at 62. No obvious plateau is visible within the mileage ranges Garmin reports.

The running report did not publish equivalent VO2 max data by mileage band, but resting heart rate followed a similar pattern. Non-runners averaged 62 bpm. Runners covering 0-5 miles per week averaged 59 bpm. Those running more than 31 miles per week averaged 55 bpm. The relationship is linear throughout.

The overall averages: Garmin cyclists recorded a mean VO2 max of 51, runners 50. Both figures fall within the good-to-excellent range for recreational athletes, though the exact range depends on age and sex. How those benchmarks break down by demographic is covered in the site’s detailed VO2 max guide.

What VO2 max is

VO2 max is the maximum rate at which the body can consume oxygen during sustained exercise, expressed in millilitres per kilogram of bodyweight per minute – think of it as the sporting efficiency of the average kilogram of your body. It is the primary measure of aerobic ceiling and correlates with endurance performance across distances ranging from 5K to Ironman. It also correlates with healthspan, i.e., the length of your healthy life.

Greater training volume generally provides more opportunity for aerobic adaptation, though training intensity, recovery, and genetics also influence the outcome. The Garmin data reflects the volume relationship at a scale no laboratory study can approach, although it isn’t ‘science’ in and of itself.

Garmin estimates VO2 max via the Firstbeat Analytics algorithm, which analyses the relationship between heart rate and pace during runs, or heart rate and power during cycling with a paired power meter. Under controlled conditions with chest-strap heart rate, Firstbeat’s validation puts accuracy within approximately 5% of laboratory spirometry. The estimate is directionally reliable for tracking trends even where the absolute figure diverges from lab results.

Age and VO2 max

The age effect is significant and worth understanding separately from the training volume effect. Among Garmin cyclists, the 20-29 age group averaged a VO2 max of 57, falling to 53 for 30-39, 50 for 40-49, 48 for 50-59, 46 for 60-69, and 42 for those over 70. The decline is consistent across every decade.

This is a normal physiological process driven by reduced cardiac output and changes in muscle composition. It does not mean older athletes cannot improve their VO2 max. They can, and the training volume relationship holds regardless of age group. It means the benchmark for what constitutes a good number shifts downward with each decade, which is why age-adjusted comparisons matter more than raw figures.

What this means is that if you are trying to improve your VO2 max

The Garmin data points toward several practical conclusions for athletes tracking this metric.

Volume is the strongest lever. The data show a clear and consistent association between weekly mileage and VO2 max across all training bands. Athletes who ride or run more tend to score higher. Progressively building weekly volume is the most reliable approach.

Intensity still matters. Volume alone does not tell the full story. High-intensity efforts — intervals, threshold work, race-pace sessions — provide an adaptation stimulus that easy miles cannot replicate. A programme that combines both is more effective than accumulating easy miles.

Age adjusts the target, not the principle. VO2 max declines with age, but the training volume relationship holds across all decades. Older athletes who train consistently record higher VO2 max values than sedentary peers of the same age. The ceiling is lower; the lever still works.

Consistency over weeks matters more than any single session. Garmin’s algorithm requires qualifying sessions — at least 10 minutes at approximately 70% of maximum heart rate for running, 20 minutes of steady effort with a power meter for cycling — to update the estimate. A single hard week will not move the number. Sustained training over months will.

Track trends, not absolutes. Garmin’s estimate carries an error margin of approximately 5% under good conditions, and more under heat, altitude or optical heart rate. The value of the metric is in the direction of travel over weeks and months, not the precise figure on any given day.

What else does the data show

• Indoor running activity increased by 12.6% per user in 2025 compared to 2024, compared to 3.2% for outdoor running. Treadmill and structured indoor training appear to be driving that divergence.
• Among runners, a 23% increase in users recording both a run and a strength session in the same week reflects a broader shift in how endurance athletes structure their training. The gym is increasingly treated as part of the programme rather than optional supplementary work.
• Geographically, South Korean users recorded the highest running activity volume per user of any country, leading across running, track running and treadmill categories. France led trail running. Italian cyclists recorded the highest average ride distance at 34.73 miles per ride, ahead of Belgium at 33.05 miles and Spain at 32.80 miles. The global average was 28.59 miles.
• The 50-59 age group ran the longest average distance per session, at 5.1 miles, ahead of the 40-49 age group at 5.02 miles and the 30-39 age group at 4.84 miles. The 20-29 group averaged 4.6 miles per run. Older runners run further per session; they simply do it more slowly.
• August was the peak month for both running and cycling activity. Saturdays were the most popular day for running, Sundays for cycling.

Interesting stuff. And, yes, some of these factoids are statements of the obvious. Obvious if you already know, of course.

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Frequently asked questions

What is a good VO2 max for a recreational cyclist or runner?
Among Garmin users in 2025, the average was 51 for cyclists and 50 for runners. Both sit in the good-to-excellent range. The meaningful comparison is against your own age and sex cohort rather than the global average. Full benchmark tables are in the VO2 max guide.

How many miles per week do I need to ride to improve my VO2 max?
Garmin’s data show improvement across every mileage band from 0-20 miles per week onward. There is no minimum threshold in the data, but the gains become more pronounced above 60 miles per week.

Why does my Garmin VO2 max drop in summer?
Heat elevates heart rate relative to pace. The algorithm reads this as reduced fitness and lowers the estimate accordingly. The number recovers once conditions cool and qualifying sessions re-establish a baseline.

Last Updated on 3 June 2026 by the5krunner