QUESTION: I’ve been uploading my rides to Strava for a while now and it gives me estimated wattage, but it’s unclear to me if those numbers are any good or not compared to other riders. I’m doing ok with my times on some local segments, but what’s a good average wattage cycling in general? — Kenneth M
ANSWER: It’s unfortunately a little bit more complicated than giving you a simple wattage number, because wattage depends a lot on rider weight. A bigger rider can put out more watts than a smaller rider, but that wouldn’t necessarily mean that he’ll be riding faster — because it takes more watts to propel his heavier bodyweight.
A more useful way to compare “apples to apples” is to look at watts per kilogram (w/kg). That’s how much wattage you are generating for each kilogram of your body weight. If you consider those numbers, you can compare to someone who is heavier or lighter than you and see who is generating the most power by weight.
Power to weight ratio is very important in cycling, as it is in running. A lighter cyclist who can put out raw high wattage numbers is going to go a lot faster. This is why cyclists sometimes get obsessed with buying lighter cycling equipment.
But losing weight can make just as big or a bigger difference to your power to weight ratio. It’s near impossible to drop 10 pounds from your bike weight, but might be reasonable to lose that much weight from your body safely.
This Bicycling article examines the Strava results of a bunch of pro riders who have uploaded their rides and made them public. The article claims that a typical fit cyclist might be able to crank out 250 to 300 watts as an average for a 20 minute FTP (functional threshold point) test, while the pros usually average 400 watts. But this is misleading, because how much do those pros weigh, and how much does the “average cyclist” weigh?
A much more accurate way to look at it is this chart from Data Cranker, which shows the average watts per kilogram (W/kg) that cyclists at different abilities typically can maintain for time periods of 5 seconds, 1 minute, 5 minutes and 60 minutes.
That chart shows that a Cat 5 (lowest category) racer might be able to maintain between 2.4 to 2.9 w/kg over a 60 minute period, while an international pro could maintain a dramatically higher 5.6 w/kg or perhaps higher. If both the Cat 5 cyclist and the pro weighed 70 kilos (154 pounds), then the Cat 5 cyclist would put out an average 203 watts and the international pro would put out an average of 392 watts during a one hour period. The pro is putting out almost twice the wattage!
Do you own a smart trainer? If so, you can get an even better idea of how your wattage compares by looking at the racing category data from Zwift. Here are the categories that they recommend you race based on your FTP data and watts per kilogram.
The Zwift C category (next from the bottom) says that you should be able to ride at the level between 2.5 to 3.1 w/kg. If you want to succeed in the A category, you’ll need to be able to hit 4.0 w/kg or better. If you ride better than 6 w/kg on Zwift for any extended period in a race, they generally suspect cheating and filter you out of race results.