I was told by a friend that I should do more cardio exercises until I reach my goal weight then I can start using the weights and trying to build muscle.
Her theory is that I want be small and firm not big and firm and if I weight train at first that I'll just turn my big fat into big muscle......Is this true?
Is it okay to lift my weights and use my bowflex right away or will this just make me bigger?
your fat doesn't transform into muscle if you lift weights. that's like saying an apple will transform into an orange if you bring it to florida. they're two separate things.
muscle DOES: burn calories (even when you're doing absolutely nothing), make you able to do more cardio when you exercise (so you'll end up burning more calories at the gym than you would w/o that muscle) and help ensure you don't get injured along the way.
i'm currently doing the "cardio until i lose the weight" thing, but i also strength train. i believe that if you're looking to lose fat, there's nothing that boosts your metabolism like lifting heavy weights.
i'm not even sure if these long bouts of cardio are even important or necessary. if you want to strengthen your heart, just keep your heart rate up while you lift, or jump rope between sets. i can't say definitively that cardio is sort of a waste, but i can say that weight lifting is a huge YES. do it.
You want to do strength training 3 hours a week, and then cardio as your time allows, both for fat loss and overall health. And you want to do your cardio as interval training as that's been shown to have the most overall benefits both in terms of heart healh, cardiovascular fitness and body composition.
Though playing a competitive team sport like soccer or hockey where you run in spurts is the equivalent of doing HIIT; so you don't have to do endless treadmill or bike sprints to get those cardio benefits. Unless you actually like doing that sort of thing, that is :)