Determining muscle frailty... How many times can you sit and stand from a chair?

 

The first muscle to weaken is the quadriceps femoris.

The muscle that first weakens with aging is the 'quadriceps femoris.' Professor Sakuraba from the Graduate School of Sports Medicine at Juntendo University in Japan analyzed changes in leg muscle mass with age. As a result, the quadriceps femoris muscle mass was highest at age 25 and then rapidly decreased. On average, by age 60, it had decreased to about 60% of that at age 25. To specifically examine the rate of decline for each muscle, the research team also measured changes in muscle mass in different leg regions after two weeks of immobilization with a cast. The strength of the hamstring muscles at the back of the thigh decreased by about 14%, but the strength of the quadriceps femoris decreased by about 20%. The research team explained, "The hamstrings contain many red fibers that maintain endurance, whereas the quadriceps have many white fibers that generate quick force, so when muscles are not used or when aging occurs, the quadriceps tend to lose muscle mass first," and added, "This is also why elderly people often experience falls, because the reduction of white fibers makes quick responses difficult."

Checking whether the quadriceps muscle mass is sufficient is simple. It was already confirmed in 1999 by a research team at Massachusetts Hospital in the United States that quadriceps strength can be measured through ▲the time it takes to stand up from a chair ▲walking speed ▲walking distance. The criteria vary slightly between studies, but according to recent research by a domestic team, elderly individuals who take more than 10 seconds to stand up from a chair, walk 6 meters back and forth, and sit back down are at high risk of insufficient muscle mass, which can lead to impairments in the brain, vision, hearing, language, and mental functions. This is based on a follow-up and analysis of 81,473 elderly people aged 66 by Professor Son Ki-young's team at Seoul Asan Medical Center over a maximum of 8.9 years. The group diagnosed as normal had an average of 7.20 seconds.

In a U.S. study, men in their 50s stood up and sat down 37 times, and women in their 50s did so 35 times within 60 seconds, indicating a very high likelihood of remaining healthy until age 65. The European Geriatric Society considers it a sign of muscle deficiency if one cannot perform five sit-to-stand repetitions in 15 seconds, if walking speed is less than 0.8 meters per second, or if it takes more than six minutes to walk 400 meters.

If your leg muscles are lacking, you can strengthen your quadriceps through squats. A squat involves standing with feet shoulder-width apart, bending the knees using the strength of the thighs and hips to lower yourself down, then returning to the starting position. If the movement is difficult, you can sit on a chair and then remove the chair while maintaining that posture. Care should be taken to avoid arching the back. If performing a squat is difficult, doing a wall squat—leaning your back against the wall, extending your feet forward, and lowering yourself until your thighs are parallel to the floor before rising—can also be helpful. It is also important to consume enough protein necessary for muscle synthesis.