I've gotten several good suggestions, such as those below, but the goal here
is resistance training, not aerobic.  We do a lot of walking (we call it
hiking when we are camping).  One suggestion is for something called a
Totalgym, and I am looking into that.

As far as the juicer is concerned, it is 4 amps @ 120 volts, so that's about
480 watts.  At 12 volts, that's 40 amps assuming the inverter is 100%
efficient.  Is that practical?  Can I run it for the 10 minutes or so needed
and still start the van?  Should the van be running while I use it?  I don't
have much experience with inverters.

Thanks,

Bill

> Go running, not much equipment needed.  And when you drag yourself back to
> the van you'll get an upper body workout.

>take two kids