Losing fat..cardio intensive workouts.. Opinions on my workplan needed. ?

Fredman007 =] · Yahoo User

Okso i am 17, weigh 73kg, 180cm tall. Im not overweight, but not skinny/lean. 17%body fat I used to bike ride a lot, but stopped a year ago, and havent done much exercise other than tennis 2 or 3 times a week (training)i dont exactly eat super healthy either.I havent put on weight or etc. sort of stayed the same, even with lacking of exercise.I joined the gym this week, because i want to get a 6 pack after i slim upi am doing 1 hour body pump class on monday, 1 hour cycle class on wednesday (spin class) and friday 1 hour cardio kickboxing.will this be effective.? i did the cycle class and was sweating so much and so worn out..my mate said it should take at most 2 months tops for me to slim up if i do my 3 days a week gym + tenniswhat are ur thoughts ?