You'll never--as you've discovered--be able to do either activity particularly well if you're doing them concurrently. That is a dead-end; Just bury it. Focus fully on one thing and one thing alone.

Next, get rid of your elliptical. It's a wildly inefficient use of your time and effort.

Finally, get a Kettlebell.

According to a recent study from a well respected fitness research organization, in collaboration with an equally well respected research University, Kettlebell workouts can burn up to 20 calories per minute. This is primarily due to Kettlebell workouts being comprised of total-body movements that bring cardio and strength training together, in one quick workout.

The only other activity known to man that is that efficient is cross-country skiing, uphill, at a fast clip. Considering that your work-space likely lacks snow and hills, a Kettlebell may be more readily appropriate. ;-)

For more info, see: http://www.acefitness.org/getfit/studies/kettlebells012010.p...