Urolithin A confirmed to improve muscular endurance, but maximum strength improvement remains uncertain

As people age, the phenomenon of legs feeling heavy or easily fatigued when climbing stairs is related to a decrease in muscle mass as well as the decline in the function of mitochondria, the energy powerhouses within cells. Recent aging research is focusing on the 'Mitophagy' system, which removes damaged mitochondria, and 'Urolithin A' is known as a substance that promotes this process.

According to a video from Gyoyukhaneun Uisa! Lee Dong-hwan TV, Urolithin A is a substance produced when gut microbes metabolize ellagitannins found in pomegranates, berries, walnuts, and other foods. This can be classified as a type of postbiotic. A 2016 study showed that Urolithin A improved muscle function in rodents, but when applied to humans, it was confirmed that the ability to produce it varies significantly depending on an individual's gut microbial composition.

Changes in muscular endurance and strength of Urolithin A seen through clinical trials

Various clinical studies have been conducted to confirm the effects of Urolithin A on the human body. According to a 2019 study, when elderly individuals with low activity levels consumed Urolithin A for four weeks, it was confirmed to be safely absorbed into the blood. However, regarding actual changes in muscle function, there are differences depending on the study.

In a study of 66 elderly individuals aged 72 in 2022, the group consuming Urolithin A did not show statistically significant differences in walking ability (6-minute walk distance) or maximum ATP production capacity of hand muscles compared to the placebo group. However, in terms of 'endurance'—the ability to withstand repeated contractions of the hands and legs—the Urolithin A consumption group showed more favorable results.

Results were also mixed in a study targeting middle-aged adults. In a study of 88 adults aged 40 to 65, muscle strength increased by approximately 12% after consuming Urolithin A, but the 'maximum power' set by the researchers as a key indicator did not improve significantly compared to the placebo group. In studies conducted on athletes in 2024 and 2025, there were positive changes in fatigue or muscle damage indicators, but actual weightlifting records or running records were not directly improved.

The effects and limitations of Urolithin A must be clearly distinguished

Synthesizing the research results to date, the effect of Urolithin A is focused on the 'ability to tire less (endurance)' rather than 'becoming stronger or faster.' This is because maximum muscle strength and speed are influenced by various factors in addition to mitochondrial efficiency, such as neurological regulation, tendons, and cardiopulmonary function.

The video summarizes Urolithin A as follows. Confirmed facts are that oral consumption is possible and it is absorbed into the blood, and that some muscle endurance or strength may be improved in short-term clinical trials. On the other hand, parts that are not yet certain are whether it increases muscle mass itself or prevents sarcopenia, whether it reduces falls or definitely improves walking speed, and whether it can replace exercise.

3-step health rules for creating tireless muscles

While Urolithin A may be a new option for muscle health, it is difficult to view it as a fundamental solution for building muscle. The video presents the three most important steps to protect muscles as follows.

The first is exercise. Aerobic and resistance exercises directly affect the amount and function of mitochondria in skeletal muscles. In particular, resistance exercises such as squats, chair sits and stands, band exercises, and climbing stairs are essential for maintaining muscle.

The second is sufficient protein intake. As people age, they must eat sufficient protein to protect muscle mass and function, and it is more effective to consume it across multiple meals rather than all at once in a single meal.

The third is considering ingredients such as Urolithin A. It is desirable to consider this as an additional option after faithfully implementing the previous two basic rules (exercise and protein). When encountering new health information or ingredients, one should not simply consider whether they are effective, but carefully judge for which subjects and by which indicators they were studied.