In the real world, drafting is about riding behind another cyclist to cut wind resistance and go faster - and you can take advantage of the same technique in Zwift!
Drafting in Zwift increases your speed while you stay behind another rider. So if you're going 25 kph at 200 w while on your own, you may go 30 kph at 200 w if you're drafting another rider (these numbers are purely for illustration).
Drafting does not reduce the resistance on a smart trainer nor affect your wattage. These are separate measurements/mechanics.
How do I know if I'm drafting?
If you're doing a regular ride and are close behind another cyclist, you will draft them. If you're in danger of falling out of the slipstream, you'll see the "Close the Gap" message below your main status box in the middle of your screen.
Are there circumstances where I won't draft?
You're not allowed to draft in the following circumstances:
- You're doing a structured workout.
- You're riding a TT (Time Trial) or Tri (Triathlon) bike.
Q: Why do I have to put out the same amount of wattage when I'm drafting to keep up with the lead rider I'm drafting?
A: Speed in Zwift is calculated based on a number of factors and primarily driven by wattage. In other words, if your wattage drops, your speed will too. You may be able to put out slightly less wattage and keep pace, but if your lead rider's pace increases, you'll have to increase pace to keep up as well. Just like in real life.
Unless you see something VERY egregious, it's likely that there are other physics-related factors that are requiring you to maintain/increase your wattage to continue drafting.
Q: The physics/calculations of drafting in Zwift seem/feel off to me.
A: We're pretty confident in our physics: our team has extensive riding experience and literally read volumes on the subject. That being said, we're also always working to improve Zwift and are constantly reviewing our calculations, so if you have any feedback, let us know on the forums.