How to incorporate strength training?

[Longhorn]

My schedule is such this semester that, if I'm lucky, I can work out 30 to 60 minutes on Tuesdays and Thursdays, not at all on Mondays and Wednesdays, and generally plenty of time on Fridays, Saturdays, and Sundays. I've been doing all of my exercise on my elliptical trainer. However, I also own a home gym and have done strength training in the past.

My fitness goals are, in order of priority, to lose about 50 pounds, improve muscle tone, and avoid bone-loss problems (I'm female and 50.)

In the past, I would do an upper body workout one day and lower body the next but I no longer have that kind of continuity in my schedule. Any suggestions on how to use what time I have to work on my goals? Keep in mind that due to the 14-hour days that I work on M-W, I sometimes don't exercise at all the day after.

Thanks! :hi: