Q: I want to lose a few pounds within 5 weeks for a trip. If I cut out cardio just until my trip and used the 20 minutes I'd spend on cardio for weight training instead, will I lose weight faster or slower?

A: Losing a few pounds in 5 weeks is quite easily done. There's nothing wrong with 20 minutes of cardio a few days a week, but yes, you do also need to do weight training for optimal fat-burning. When you weight-train, make sure you use heavy (heavy for you, not heavy for someone else!) weights and focus on big exercises like the squat, deadlift, lunges, rows, and presses. Doing small stuff like bicep curls alone will do nothing for fat burning.

So my advice to you would be to keep cardio as is, but add heavy whole-body weight training AND, if you're not doing it already, adopt a fat-burning diet. You can fill out http://www.mikesfitness.com/content/fitnessguide specifying 'Lose Fat' as your goal to get a complete weight training and diet prescription. You don't need to follow them exactly of course, but they should give you a good idea of what to do. Losing 5-6 pounds of fat in 5 weeks is very doable. Good luck!