The “Japanese Ab Exercise” is a simple, no-movement technique that has gained viral popularity, primarily through social media, for its purported ability to flatten the stomach and promote weight loss. Developed by Japanese reflexologist Dr. Toshiki Fukutsudzi, the method involves lying on the floor with a tightly rolled towel positioned under the lower back for a short duration each day. This passive postural adjustment requires only a towel and approximately five minutes.
Anatomical Focus of the Method
The exercise’s mechanism centers on gently forcing the spine and pelvis into a more neutral alignment, counteracting the common forward slump caused by prolonged sitting. Placing a firm roll (about 7 to 10 centimeters thick) directly under the lumbar spine at the level of the navel exaggerates the natural arch of the lower back. This specific posture is believed to correct pelvic misalignment, which can cause the abdominal area to protrude even in individuals with little excess body fat.
The primary anatomical target is the deep core stabilizers, particularly the transverse abdominis (TA), rather than the superficial “six-pack” muscle, the rectus abdominis. The TA wraps around the torso like a corset, functioning to compress the abdomen and stabilize the spine and pelvis. By temporarily positioning the spine in this extended posture, the exercise may encourage a subtle, isometric engagement of the TA as the body attempts to maintain stability against the towel.
Separating Fact from Exaggerated Claims
The most common claims associated with the Japanese towel exercise—such as melting belly fat, achieving a flat stomach in 10 days, or guaranteed weight loss—are scientifically unsupported and misleading. The body cannot be forced to lose fat from a specific area, a concept known as spot reduction, as fat loss is a systemic process requiring a sustained caloric deficit. Lying on a towel for five minutes does not expend enough energy to contribute meaningfully to fat loss.
Any immediate or short-term slimming effect reported by users is a result of improved posture and spinal realignment, not actual fat reduction. When the spine and pelvis are corrected, the abdomen is held in a more compressed position, making the waistline appear visually smaller and flatter. The exercise is a tool for posture correction and potential back pain relief, not a substitute for comprehensive fitness or a healthy diet.
Technique, Modifications, and Safety Considerations
To correctly perform the exercise, roll a bath towel tightly into a cylinder approximately 7 to 10 centimeters in diameter. Lie supine on a firm, flat surface, placing the rolled towel horizontally under your lower back, directly beneath your navel. Extend your arms straight above your head, palms down, with the pinky fingers touching, and stretch your legs straight with the big toes touching and heels slightly apart.
Hold this specific position for approximately three to five minutes, breathing slowly and deeply throughout the duration. Beginners should start with a smaller towel roll and a shorter time, perhaps one minute, to allow the body to adjust to the spinal extension. Safety is paramount, so those with pre-existing back conditions, such as herniated discs or significant mobility issues, should consult a healthcare professional. To exit the position safely, roll onto your side before slowly pushing yourself up, rather than sitting straight up, to protect the spine.