Actress Ha Ji-won, 48, recently revealed on television that the secret to maintaining her firm, toned physique—which she compares to her conditioning in her 20s—lies in "holding" exercises.
Appearing on the tvN variety program You Quiz on the Block, Ha described her personal fitness routine. "At minimum 15 minutes, but usually 30 minutes, I focus on just one movement a day," she explained. "The key isn't simply bending and extending the joints; it's holding the posture until you feel an intense stimulus, almost like an electric surge through your body."
She added that she performs these static holds whenever possible, even while riding in a car. "You have to give the muscles a strong stimulus so they stay engaged," Ha noted, adding with a laugh: "If you tell them to lengthen, they understand. If you talk to your muscles, they relax, too." Beyond holding poses, Ha weighs herself daily and incorporates massage to relieve physical tension caused by daily smartphone use.
The Science Behind Isometric Exercise
While Ha did not use formal medical terminology on air, sports scientists recognize her static holding technique as isometric exercise. Classic examples include planks and wall squats. Unlike traditional resistance training where joints move through a full range of motion, isometric exercises involve contracting target muscles against a fixed resistance—such as gravity or a wall—without moving the surrounding joints. Although static, the body expends substantial energy to maintain the posture.
The principal advantage of isometric training is its minimal burden on cartilage and joints. Because it eliminates repetitive joint friction, physical therapists frequently prescribe isometric movements during early rehabilitation for anterior cruciate ligament (ACL) tears, frozen shoulder, and herniated discs. Furthermore, these exercises require no specialized equipment and can be performed anywhere.
Static holds also offer notable cardiovascular advantages. A study by researchers at Beijing Sport University published in Frontiers in Public Health found that isometric exercises like wall squats were remarkably effective at lowering blood pressure. The analysis revealed that isometric training reduced systolic and diastolic blood pressure by an average of 8.24/4.00 mmHg, surpassing reductions achieved through aerobic exercise (4.49/2.53 mmHg), combined training (6.04/2.54 mmHg), and high-intensity interval training (HIIT).
‘Talking to Your Muscles’: The Mind-Muscle Connection
Ha’s practice of "talking to her muscles" also aligns with sports science principles. Known as "internal focus," this technique involves consciously concentrating on the target muscle's movement and sensation during exercise.
Electromyography (EMG) studies demonstrate that maintaining an internal focus can increase muscle activation by approximately 20% to 30% compared to mindlessly completing repetitions. Intentionally directing mental focus toward a target muscle strengthens neural signaling from the brain, maximizing exercise efficiency and muscle recruitment without needing additional weights.
