lets start off... in high school my weight was as high as 240 lbs. i am 5'11". during my senior year i lost quite a bit of weight and got down to as low as 175 lbs. i am now 20 and i currently weigh 208 and i need to get down to 175 or 180 again. i think my problem was that i lost the weight with a bad diet plan that i could not stick to. i need to make a life style change that will help me keep this weight off and become healthier. i have started working out again but i'm not real sure what i should be doing... i have a heart rate monitor and i'm not sure what i should keep my heart rate at to loose weight. should i stay between 65 and 70% to burn fat or should i be at 75 to 85 % for cardio?? also, should i be lifting weights while trying to loose weight? i don't want to waste my time doing this incorrectly, thats why i'm asking for help... i tried looking around and i didn't really find to much that applied to me. thanks for any help..