For weight loss i'm mainly doing cardio, how much cardio should i be doing if i go 5-7 days a week?
I usually use an elliptical, or i'll use a treadmill, i usually switch it up.
The general consensus now is that an hour of weightlifting three times per week is far superior for weight loss than trying to do lots of cardio. I personally started with 3 days of weightlifting and cardio (running or swimming) on my off days. Lately I've been doing more/heavier weightlifting and a lot less cardio. "They" say doing lots and lots of things like running is bad for your joints, especially if you are overweight. Something to keep in mind.
In the end Zoe is right though. Weight loss/gain is really done in the kitchen. Sorting out your diet is, by leaps and bounds, the most important aspect of losing weight/being healthy.