A Zwift one? That would be good training before your first real one - shame I don't have a treadmill or I'd be up for that.I've been thinking about doing one, there's a Duathlon type of event on Zwift this weekend so might give it a go, there's also a event at a race circuit in Leicestershire in March not sure if I'm going to sign up for it.
The one I'm looking at is also at a race circuite (Castle Combe) - if I'm brave enough to give it a go I'll let you know how it goes!