Last week, we started a new series on measuring and using power – without the need for a power meter or fancy laboratory testing.
In short, you don’t need an expensive lab test to determine 3 important performance numbers—power at lactate threshold, maximal oxygen uptake and meters-per-minute of climbing.
Last week, I explained how to do the testing used to calculate the numbers for these. I’ll finish up today by showing you how to use your test data to make the calculations
According to Garmin Sharp team director Jonathan Vaughters, this measure is important to pro cyclists. Why? Because climbing is contingent on your power-to-weight ratio.
Determining meters-per-minute climbed gives you an objective rating of your uphill ability without the need for other calculations.
To do it, simply divide the height of the climb by the number of minutes it took you to get to the top. For instance, if you climbed 186 vertical meters in 10 minutes, your meters-per-minute figure is 18.6.
What does this number mean? According to Vaughters:
19 meters per minute = Survive the Tour de France
22-25 meters per minute = Place top 30 in the Tour
30-32 meters per minute = Win climb of l’Alpe d’Huez
Data for recreational racers isn’t available, but here’s an educated guess: Category 1-2 riders will range from 20 to 25 meters per minute. Masters will do 17-22, depending on age.
If those numbers seem high compared to Vaughters’ values, remember that in U.S. racing, climbs are usually short by European professional standards. The shorter the hill, the easier it is to maintain a high rate of climbing speed. And if a domestic race does have a long climb, it’s usually done just once, in contrast to the Tour, where the l’Alpe d’Huez ascent is typically the third or fourth mountain of the day.
To calculate your average watts for the climb:
1. Multiply the number of vertical meters in the climb by the total weight of bike and rider in kilograms.
2. Divide the result by the time of the climb in seconds.
3. Multiply that answer by 10 and add 60 (a constant that reflects rolling resistance, chain friction, etc.)
For example, if you climbed 186 meters in 10 minutes and the total weight of bike and rider is 80 kg, your average wattage is 308.
To calculate your VO2 max:
1. Divide your average watts from the above calculation by an efficiency factor of 72 to get your total oxygen consumption in liters per minute.
2. Multiply the result by 1,000 to get milliliters of oxygen consumed.
3. Divide milliliters of oxygen by your body weight in kilograms to get VO2 max expressed in the standard ml/kg/min.
For example, if your average watts is 308 as in the above example, and your body weight is 70 kg, your VO2 max is 61.1 ml/kg/min.
In Vaughters’ view, speaking from his experience in European cycling, a VO2 max of over 70 is outstanding, and anything above 60 is excellent.
These figures are for Vaughters’ home testing grounds west of Denver at elevations around 7,000 feet. At sea level, VO2 max results are about 8 percent higher. So, you flatlanders need values of about 76 and 65, respectively.
My RBR eArticle Equations for Cyclists details how to calculate these and other such power numbers.