May be too much fat accumulation, strengthen the precise training of abdominal muscles. One issue of Sohu Home Live was as thin as lightning, which was very thorough. Probably the recommended action is Russian rotation (training the muscles on both sides of the waist) to lift the thoracic spine and correct the flat support (exercising the abdominal muscles). Pay attention to activating abdominal muscles before exercise to protect lumbar spine. If you can't do the correct plate support, then downgrade first, so as not to become a "waist grinding".