Singer Shinji recently revealed that she has officially started strength training after learning that her physical condition mirrors that of someone much older.
In a video posted to her YouTube channel Eotteoshinji, Shinji visited a gym to undergo personal training (PT) at the suggestion of her husband, Moon Won. "It was my husband's long-held wish, and it took a major decision on my part, but I'm going to try working out," Shinji shared with a laugh. "He bought me PT as a gift, so I ended up exercising whether I liked it or not."
Despite years of performing on stage, Shinji realized the severity of her physical state when her muscle mass proved too low for an InBody composition scanner to properly register a score. During a basic fitness assessment, her legs shook uncontrollably while performing bodyweight squats. When trying an upper-body pull machine with a minimal 5 kg weight, she struggled to complete the movement.
The trainer highlighted significant issues stemming from a lack of lower-body muscle. When Shinji extended her leg, her hip-joint alignment collapsed rather than remaining straight. The trainer warned that without corrective work and muscle growth, she could soon develop chronic knee problems. "At this rate, I'm basically a walking general hospital," Shinji admitted.
Irregular Eating Habits Drive Muscle Loss and Blood Sugar Risks
Shinji's severe lack of muscle stems from long-standing, unhealthy dietary habits. Known for skipping meals and eating very little, she typically consumes at most one or two small meals a day.
When a severe calorie and protein deficit persists without the physical stimulus of strength training, the body enters a survival state. To conserve energy, it breaks down muscle tissue before fat to use as fuel.
This loss of muscle extends beyond reduced stamina—it directly threatens blood sugar regulation. While thin, lightweight individuals are often assumed to be safe from metabolic issues, skeletal muscle serves as the body’s primary storage site for glucose, converting it into glycogen. When muscle mass is severely depleted, excess blood sugar has nowhere to be stored, leading to sharp spikes and crashes. Consequently, underweight or "skinny-fat" individuals face an elevated risk of developing metabolic conditions, including type 2 diabetes.
How Muscle Deficiency Endangers Knee Joint Health
While obesity is well known for increasing joint strain and triggering osteoarthritis, a severe lack of muscle can be equally damaging to joint longevity.
Lower-body muscles act as natural shock absorbers for bones and joints. Muscle groups extending from the quadriceps at the front of the thigh to the glutes and calves absorb body weight and impact forces during movement. When lower-body muscle mass is insufficient, those forces travel directly into knee cartilage and bone, accelerating wear and tear.
Furthermore, muscles and ligaments work together as structural stabilizers that keep the knee joint properly aligned. When muscle strength wanes, joint stability declines, significantly increasing the risk of ligament strain and meniscus injuries.
Rebuilding Strength Through Lower-Body Workouts and Targeted Nutrition
To address her muscle deficiency, Shinji began incorporating foundational lower-body exercises, such as squats and leg presses. Lower-body training is the most effective approach for increasing overall muscle mass, as the hips, thighs, and legs contain approximately 50% of the body's total skeletal muscle. Compound movements like squats, lunges, leg presses, and deadlifts engage a vast network of muscle fibers simultaneously.
To maximize muscle growth, structured nutritional support is essential alongside exercise:
Slight Caloric Surplus: Consuming slightly more calories than required for weight maintenance provides the necessary energy and nutrients for muscle tissue synthesis.
Distributed Protein Intake: Rather than consuming daily protein in a single large meal, spreading intake across three to five meals optimizes muscle protein synthesis. For muscle gain, experts recommend 1.6 to 2.2 grams of protein per kilogram of body weight daily—translating to roughly 80 to 132 grams per day for an average adult woman.
Complex Carbohydrates: Carbohydrates provide essential fuel for workouts, prevent the body from burning protein for energy, and aid post-workout recovery. Sustained energy sources like brown rice, sweet potatoes, and regular potatoes are ideal choices.
