"Just say NO!" to cardio

So I have been going to the gym about 5 days a week for 6 weeks.  When I started my body fat percentage was 24.5%; I took it again today...it was 21.5%  After a few simple calculations, I estimate that I have lost 6lbs of fat and gained 1lb of muscle.  I have done almost no cardio, except for 10 mins once or twice a week at the end of my workout to add to my calorie burn. 
Most of us know that your metabolism slows down as you age, making it harder to maintain and lose weight.  Your metabolism slows due to loss of muscle, as women we lose about half a pound of muscle every year after the age of twenty, one pound after the age of thirty and at the age of menopause that number will double!  That will equal 5lbs of weight gain in your 20s, 10lbs in your 30s and 20lbs in your 40s and 50s.  So without having changed your diet or exercise regimen you have gained 30-40lbs. 
You have to lift weights and you have to push yourself. 
I can't tell you how many times I walk past a woman sitting on a circuit training machine zoned out lifting 5 lbs on a muscle that can easily lift 20lbs or more.  It has to hurt; no pain, no gain.  If you reach 12 reps and you can still do more, up the weight.  Try to up the weight you lift a little every time you workout that muscle.  If you are working really hard, you will burn as many calories in an hour lifting weights as you will doing cardio.  Bonus: After lifting your metabolic rate stays up for at least 15-72 hours (depending on if you worked concentric or eccentric muscles, more on that next time) as your muscles work to repair themselves.  After you stop doing cardio your metabolic rate goes back to normal almost immediately.  Furthermore, after more than 30 mins of cardio your body can start to cannibalize muscle to give you the energy to keep going. 
You don't gain muscle from doing cardio, you have to lift weights.  Step away from the treadmill and head over to the scary weight room.  It is about time women take it over; how awesome would it be to see more women in the weight area then men?!

One caveat, if you are training for a marathon or an endurance event, of course you are going to be doing cardio, but if you just want to lose weight and increase muscle mass, weights, weights, weights!