So I want to lose belly fat and my friend said to do sit ups. Then my sister told me that it doesn't help me lost fat, it just builds muscle under the fat. Any tips and suggestions?

Your sister is right. There is no such thing as spot reduction of fat, and sit ups only build and tone underlying abdominal muscle. Fact is, sit ups aren't even that great of an exercise. To reduce fat, you have to improve your diet and increase the heart rate for sustained periods of activity or exercise. Fat is reduced from the sum total of body fat over the whole body, areas that most fat is stored (hips/waistline) will be the last to become fat free. Be assured even with the best methods, results will take awhile.

Yeah .. Sit ups will increase muscle tone, and by doing them you do exert a good amount of energy which in itself burns calories, and that helps to burn up fat reserves .. But .. Spot reducing is a falicy. 

The best way to reduce fat throughout your entire body is to do it the old fashioned way by increasing physcial activity and decreasing calories by maintaining a good healthy diet.

The best exercise for "Belly fat" is Sit ups. Only & only sit ups.

Your stomach has a muscle then naturally a healthy layer of fat is covering it. When we don't control our nutrition & transfer unhealthy products inside our body the fat gonna increase. Now, (sit up) is not the only exercise but the best one. When you do sit ups, you focusing on your stomach literally. "Sit up" designed for "Belly fat" it's a science of work out. It burns your stomach fat & build your muscles in the same time, both together. From the inside your muscles get built, from outside your fat get burnt. But (as you should know, work-out & gym is a very sensitive sport & activity  specially for ladies) so, when you doing sit ups, you only focusing on areas under your chest to the end of your belly & stomach. For a better shape, you better to do movements to focus on the sides of your stomach as well (if needed) to make sure you fit it up.

-Running helps to lose stomach fat as well (without focus on belly but improves to the stomach)

-All kind of Cardio activities would help you out.

-There's so many stomach movements such as (Leg rises, Crunches, Modified V-sits, hundreds, Knee crunches,Cross crunches, sitting twists, bicycle crunches)  that you can try.

-Besides all these, nutrition, you have to make sure you having a good nutrition. (having diet & nutrition doesn't mean cut all of your meals no!  .. There's some products that we know are harmful generally (like lipids or processed foods) avoid them. Then find out about your body's metabolism & blood preference . See what things are so good for you & what things are so bad for you. (your own personal conditions)  also take advice from a nutritionist for a better plan then make your diet & nutrition plan by it.

-Note: It's important to don't find unrealistic expectations about yourself as well. One of the most important factors in gym is about "Body type" . Each body type react to gym & (varied movements of gym in a different way) so the best thing is to know your body type & stick your expectations by it. Don't compare yourself with anyone. You have your own body type & your own metabolism.

Check this link for more information about body types. www.superskinnyme.com/body-types.html

Wish you the best of luck. Keep going & never give up. :)

I think follow a system to do this.

You need a guide and it will easy to solve your problem

     
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