Yep did it last year as well, didnt walk on the bike but walked virtually all the "run" and yes it was roasting. Doing the Marmotte this year though, but will go back one day and do a proper job.
With the turbo you have to have some sort of feedback so that you can track any progress. i.e distance, time etc but for this you need the same controls in place each time so you are comparing like for like.
Overrated for me would be the £200 spent on orthotic insoles, all they made me do was instantly grow half an inch, heightwise that is, plus nutritional supplements, better off eating the packaging.