This morning, rather than go out on a 1-1.5 hr bike ride, I opted to put my bike on the trainer, do some spinning, and ended up popping "Spinervals - Sweating Buckets" into my DVD. Not sure who all uses Spinervals or how this one compares to others, but I think it was time well spent. Normally, I would much prefer riding outside, but it was just too cold at 6am for me to hop on my bike this morning. I started off thinking "Oh well, this was better than nothing". However, it may have actually been better than my outside ride would have been. The workout seemed well structured. I also think I put more effort into it than I would have otherwise.
If anyone has a favorite Spinervals, let me know. I can imagine getting bored quickly if I don't have some variety here.. I may end up using these once a week so that I don't limit my cycling to the weekends.