Actually, I usually have three rest days off during any given week: Tuesdays, Thursdays and Fridays. I tend to prefer longer, ultra-intense sessions. Every now and then I'm able to squirt in a power walk during my lunch hour but not that often.
My schedule is:
Saturday: aqua training 3:00 (cardio, total muscle conditioning including lower body, core and upper body)
Sunday: another 3:00 session, including about 1:15 cardio, and then total-body muscle conditioning (including lower body, core and upper body) with heavy weights
Monday p.m.: session about 1:30, with about 1:10 or 1:15 cardio and 15 / 20 minutes core
Wed. p.m.: session about 1:30, with about 1:05 cardio, 5 minutes of barbell leg work and about 15/20 minutes of core.
That seems to work quite well. A trade-off I have to make for working out on Mon. and Wed. p.m. is that I get in a kick-ass workout and sleep miserably that night, which makes Tuesdays and Thursdays naturals for rest days.
A-Jock