Emerging Sports Nutrition Star? Urolithin A May "Rejuvenate" Mitochondria and Boost Your Endurance

Recently, a research team from Beijing Sport University published a review in the journal Frontiers in Nutrition on the application of UA in sports nutrition, systematically summarizing its potential journey from the lab to the playing field. Today, let's talk about this rising star in sports nutrition.

What is Urolithin A? Why is Supplemental Intake Needed?

UA is not directly obtained from food; it is the "handiwork" of our gut microbiota. When you consume foods rich in ellagitannins, such as pomegranates, strawberries, and nuts, specific gut bacteria convert them into UA. However, research shows that only about 40% of people harbor gut bacteria efficient at producing UA, and this ability can fluctuate with age and environmental changes. This means that relying solely on eating pomegranates to obtain sufficient, stable UA is likely inefficient and unreliable. Therefore, direct intake of synthetic UA through dietary supplements has emerged as a more effective option to harness its benefits.

A Multi-Faceted Performance Enhancer: Comprehensive Support from Bones to Muscles

Research indicates that UA may optimize an athlete's physical condition across multiple dimensions:

1. Strengthening the Foundation: Protecting Bones and Joints

• Bone Health: UA can dually regulate bone metabolism—it promotes new bone formation while inhibiting bone loss. This is particularly important for endurance athletes (e.g., long-distance runners, swimmers) who may face risks of decreased bone density over time.

• Improving Oxygen Uptake & Endurance: A study on healthy older adults found that supplementing with UA (1000 mg/day) for 4 months significantly increased peak oxygen uptake (VO₂peak) and improved performance in a 6-minute walking test. This benefit is attributed to UA's potential to improve cardiac pumping function and promote angiogenesis (new blood vessel formation) in skeletal muscle.

• Boosting Muscle Strength & Endurance: In the same study, the older adults showed significant increases in hamstring maximum torque and average peak torque. Among young resistance-trained individuals, an 8-week trial found that UA supplementation combined with training significantly increased "repetitions to failure" and improved maximal voluntary isometric contraction force of the quadriceps.

• After high-intensity exercise, micro-damage in muscles triggers inflammation and oxidative stress, leading to soreness and fatigue. Studies show that UA supplementation can significantly reduce levels of C-reactive protein (CRP, an inflammatory marker) in athletes' plasma and enhance the synthesis of antioxidant molecules (like glutathione) in the body, thereby helping the body recover from fatigue faster.

Core Mechanism: Providing Maintenance for Cellular "Powerhouses"

The key to all these benefits of UA lies in its profound "maintenance" of the cell's "powerhouse"—mitochondria.

• Clearing Out Aged Mitochondria: UA is a known activator of mitophagy. It initiates the cellular "recycling" program for dysfunctional, old mitochondria, making room for the generation of new, healthy ones.

• Improving "Engine" Efficiency: While clearing out old components, UA can also enhance the function of mitochondrial respiratory chain complexes, increase the synthesis efficiency of ATP (the body's energy currency), and boost fatty acid β-oxidation, allowing the body to utilize fat for energy more efficiently during exercise.

Simply put, UA acts like a senior technician, capable of not only clearing out inefficient old "engines" (mitochondria) within muscle cells but also enabling new "engines" to run stronger and longer. This is the fundamental reason behind its ability to enhance endurance and combat fatigue.

Safety and Supplementation Suggestions

Safety is the primary consideration for any supplement. Multiple human trials have confirmed that UA demonstrates a good safety profile and tolerability at daily doses of 500-1000 mg for up to 4 months, with no significant side effects observed.

Based on current research, for fitness enthusiasts interested in trying UA, the following preliminary suggestions can be considered:

• Dosage: The dose shown to produce significant effects in most studies is 1000 mg per day.

• Frequency: Due to its relatively long half-life (approximately 17-58 hours), once-daily intake is sufficient.

• Timing: Considering that UA reaches muscle tissue in its active form approximately 6-8 hours after ingestion, supplementation 6-8 hours before exercise might theoretically maximize its benefits for athletic performance.

Summary and Outlook

With its unique core mechanism of "mitochondrial optimization," Urolithin A demonstrates multi-faceted potential—from enhancing bone and joint health, boosting muscular endurance and strength, to accelerating post-exercise recovery. It acts like an "all-rounder," filling some gaps left by traditional sports supplements (which often target only strength or recovery individually).

Of course, many of the current promising findings come from animal studies and research on older populations. More high-quality clinical research is needed to verify UA's effects in young, healthy athletes, determine the optimal supplementation protocol, and understand its long-term implications.

Nevertheless, supplementation strategies based on cellular energy metabolism are undoubtedly opening a new door for sports nutrition. Urolithin A, this rising star originating from the pomegranate, may well secure its place on the future map of athletic performance optimization.

Reference:
Wang M, Yu L. Emerging evidence of Urolithin A in sports nutrition: bridging preclinical findings to athletic applications. Front Nutr. 2025;12:1585922. doi: 10.3389/fnut.2025.1585922