Does Zwift racing have the same physiological requirements as a normal outdoor race?

Sure, there's plenty of articles out there right now about how to race on Zwift, focussing on the fast start (but isn't any short race typically a fast start (think criteriums or cyclo-cross), the different dynamics of the bunch and drafting (if you're not moving forwards you're moving backwards applies equally inside and outside) and so on.

The above graph shows two separate races, a 1h20min Zwift race and a 1h40min outdoors road race. As you can see, the majority of the Zwift race is tempo and threshold, with only 5% in Z1 (recovery, generally freewheeling), whilst the road race had over 25% in Z1, but also had more time in Z5 and Z6. For both races, Z7 is the sprint at the end.


  • Zwift racing is always 'on the pedals', no freewheeling, little chance for recovery and rewards those with the best aerobic fitness. 
  • Zwift racing rarely ventures into Z4-Z6; sweet spot training is perfect for Zwift racing.
  • Outdoor racing is 'more peaky', the additional rest/recovery allows for more high watt efforts, while the constant tempo of a Zwift race drains and discourages multiple anaerobic efforts.
  • Whilst the above is a long race in terms of Zwift racing, the shorter races exhibit a similar curve.
The following chart is from the above Zwift race.

As you can also see, the racing is hard on a physiological level. Currently my FTP/CP is set at 280W and my W' at 20,000. The modeling from this race predicts a FTP/CP of 274W and a W' of 19,400, so I was pretty much at my physiological limits in this race.

Interestingly, the way a Zwift race gradually wears you down is a different sensation to an outdoors road race. Outdoors, the attacks are aggressive, and when you're at your limit you know - you know in advance that you won't be able to follow the next attack! In this race I felt confident that I could attack in the finish (this was the shorter, hillier, Richmond course with the uphill drag finish), however I could only follow!