I don't sail much in winter, so on the weeks I don't windsurf, I do a 2km run around the local oval and/or a 10km bike ride up a hill and a 30 minute upper body session at the gym followed by 2km on the treadmill at 3 degrees. Seems to do the trick. I think the important thing is work rate and removing the crap from the blood stream.
Yes, unfortunately I have learnt long ago that I would buy something like that, use it for about a week and be really pumped on it and then something would come up on the weekend, I would miss the first session and then forget the second and then feel to guilty to start again and it would end up shelved....
I prefer to just be active, do fun things, eat plenty of steak and veggies and not drink too much.
Im not an elite windsurfer so I don't need to be that fit....
If Im not enjoying it, I probably wouldn't do it....
I suppose it is a good time filler when there is no wind around....
And to top off the arguement.... JP, Neil Pryde, Naish etc. all tell me that it is not how fit I am that will make me a better sailor, that it is their new board or sail that will perfect my technique and mold me into the perfect windsurfer....
Best way to get fit for windsurfing is to windsurf more Pitty there has not been much wind this winter as it kills that get fit for windsurfing plan!
You are right there. If I was windsurfing more, I wouldn't bother with the running or gym work (which I don't do in summer). The great thing about windsurfing is you are exercising and don't know it.
Pitty there has not been much wind this winter as it kills that get fit for windsurfing plan! 
