I hav kno clue..sounds hard…but jus try and jogg mayb like 2x or 3x times a week?
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hey, im skinny too with a big butt and ive also had a problem with getting my stomach flatter to enhance my butt so to get a flat stomach just do alot of crunches….u know that ball they show on tv about getting a better result in crunches? Well i just use a pillow to give me the basically the same result….also u could try a breathing technique where u inhale and exhale but keeping your stomach tight a couple of times each day….for a bigger butt do alot of squats and u could try what i do….get a chair and hold on to it while u put one leg on a bed or something and do squats like that im not sure how long it took to work i think about the 2nd week i saw results but hope i helped!!!!
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If you don't want to lose weight but want to get a bigger butt go to gym. There you can do weight training with big weights and short sets. Sets of 8-10 and three times in a workout. This wont burn that much calories, and remember to eat enough, food with a lots of proteins like eggs. You might try some recovery drinks, which also have a good amount of proteins. But in the end, if you are exercising then you are consuming more energy and you need to eat more to keep your weight.

For the flat stomach just start to do basic sit-ups, take a target of 100 sit-ups a-day for starters. Do 3 x 30 sets or do as long sets as you can, just get that 100 sit-ups in workout session full. Getting a flat stomach you just need to do a lots of ab exercises.
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