It is said that sitting in a chair, as long as you keep your body straight, your abdomen will exert strength, which can not only lose weight but also avoid waist muscle injury. Is it true?/You don't say. Forget losing weight, it won't increase the calorie consumption of a few calories. Avoid waist strain and straighten your back in all movements, not just sitting. For example, when bending down to get something, if the action is correct and the back is straight, it should be squatting. Pay attention when you are old. This kind of protection is still quite effective.