VAM in cycling: what it is and how to calculate it

In cycling, VAM are the acronyms of velocità ascensionale media, in Italian: the average ascent speed. It measures how many meters of unevenness you climb in an hour and is expressed in meters per hour (m/h). Do not confuse it with the VAM of the runners (maximum aerobic speed), which is another metric: you have it explained in what VAM is in running.

Rapid response: the VAM in cycling is the positive slope that wins in a rise divided between the time that takes, expressed in meters per hour. It is calculated as follows: VAM = slope (m) × 60 ÷ time (min). It serves to compare your climbs over time, especially in the same port.

How VAM is calculated

The formula is simple:

VAM (m/h) = positive difference in height (m) × 60 ÷ climb time (min)

Example: you climb a port of 600 m of unevenness in 40 minutes. VAM = 600 × 60 ÷ 40 = 900 m/h.

Level	Time	VAM
300 m	20 min	900 m/h
600 m	40 min	900 m/h
600 m	30 min	1200 m/h
1000 m	60 min	1000 m/h

For the data to be useful, measure only the ascent stretch: from the beginning of the slope to the top, without descents or stops in the middle.

VAM and watts per kilo

Going up costs energy because you raise your weight and that of the bike. Physical models of cycling break down power in several terms: gravity, rolling, air and speed changes (di Prampero et al., 1979; Martin et al., 1998). Only with the end of gravity, the power per kilo of total mass (cyclist and bike) is approximately:

W/kg ≈ VAM × 9,81 ÷ 3600, which is VAM ÷ 367.

At 900 m/h that works out to about 2.45 W per kilo of total mass just to overcome gravity. The actual power is somewhat higher, because you also have to beat the tread and air. That's why this account serves as guidance, not to replace a potentiometer.

What conditions your VAM

The slope: In tougher ramps, a greater part of your power turns to climbing and less is lost with the air, because you go slower. With the same power, the VAM is usually higher in steep ascents than in stretchers.
Total weight: biker, bike and whatever you're wearing.
The wind and the wheel: the wind in favor or to go to wheel change greatly the result in ports stretched.
Duration: a short climb can be made stronger than a long port.
The firm and the heatespecially in MTB.

How to use VAM in your training

Choose a reference upload near home, between 10 and 30 minutes.
Bring it up in similar conditions (no strong wind, well rested, no wheeling) every few weeks.
Calculates the VAM and write it down along with your heart rate or your average power and your sensations.
Compare yourselfNot with other cyclists on other climbs.

If you train with power or heart rate, combine VAM with your HR and power zones and monitor the training load to avoid getting fatigued to the test. If you do MTB, you also have high-intensity training in MTB.

Common errors when interpreting VAM

Compare climbs with very different slopes.
Include flat sections or descents in the calculation.
Using a mismeasured level: GPS may vary. If you can, use the port's official unevenness or barometer.
Compare your VAM to that of professionals: the context (weight, wheel, duration) is totally different.

What a Coach Says

«The VAM serves me to compare the same cyclist in the same port. Compare with what someone else does on another climb says very little." — Marc Bañuls, coach with more than 15 years of experience

Frequently Asked Questions

What does VAM mean in cycling?

Average ascent speed (velocità ascensionale average): the meters of elevation that you rise in an hour, in m/h.

How do I calculate my VAM?

Multiply the slope of the climb in meters by 60 and divide it between the minutes you took.

Is cycling VAM the same as running VAM?

No. In running, VAM is the maximum aerobic speed, a speed of run in km/h. In cycling it is a vertical speed in m/h.

Can I estimate the watts with the VAM?

Approximately: VAM ÷ 367 gives the watts per kilo of total mass needed to overcome gravity alone. The actual power is somewhat higher by rolling and air.