Potential and Mechanisms of the Functional Plant Lycium barbarum in Sports Nutrition and Fatigue Mitigation

1. Introduction

In modern society, the accelerating pace of life, increasing work-related stress, and greater physical demands have made fatigue a widespread health concern. Persistent fatigue not only reduces quality of life but is also associated with metabolic disorders, impaired immune function, and elevated risks of cardiovascular disease. This has driven growing interest in identifying safe and effective natural compounds with anti-fatigue potential, which are of particular relevance in the fields of sports nutrition and health promotion. Lycium barbarum L. (commonly known as goji berry), the mature fruit of a Solanaceae plant, has long been regarded in traditional Chinese medicine as a superior tonic for nourishing the liver and kidneys, replenishing vital essence, and improving vision. Modern pharmacological studies have revealed that extracts of L. barbarum contain diverse bioactive constituents, including polysaccharides, flavonoids, betaine, and carotenoids, which exhibit antioxidant, immunomodulatory, anti-aging, and neuroprotective activities. Among these, Lycium barbarum polysaccharides (LBPs) are considered the primary active fraction. In recent years, increasing research attention has been directed toward their role in exercise-related health, particularly their potential to alleviate fatigue, enhance endurance, and support post-exercise recovery. This review aims to provide a comprehensive overview of L. barbarum extracts, focusing on their major bioactive components, mechanisms underlying anti-fatigue and exercise-enhancing effects, evidence from experimental and clinical studies, safety evaluations, and future research perspectives.

2. Major Components of Lycium barbarum Extracts and Their Biological Properties

Goji berries are rich in diverse bioactive constituents, each contributing uniquely to fatigue alleviation and the maintenance of exercise-related health. Among them, Lycium barbarum polysaccharides (LBPs) are regarded as the key functional component, accounting for approximately 5–8% of the fruit’s dry weight. LBPs are composed of multiple monosaccharide residues, including arabinose, galactose, rhamnose, and glucose. They exert antioxidant effects by scavenging free radicals, enhance mitochondrial energy metabolism, and modulate immune responses, thereby improving the body’s adaptability to physical exercise. Flavonoids in goji berries also display strong antioxidant and anti-inflammatory activities. By regulating the Nrf2/HO-1 signaling pathway and inhibiting lipid peroxidation, they can effectively mitigate exercise-induced oxidative stress. Betaine, another important anti-fatigue component, promotes fatty acid oxidation and reduces lactate accumulation during exercise, thus delaying the onset of fatigue. Carotenoids—mainly zeaxanthin and its esters—possess notable antioxidant and eye-protective properties and can further alleviate exercise-induced oxidative damage and inflammatory responses. Overall, goji berry extracts provide natural and comprehensive support for exercise health through the synergistic actions of multiple bioactive components and their multi-target regulatory mechanisms.

3. Mechanisms by Which Lycium barbarum Extracts Alleviate Fatigue

The anti-fatigue and exercise-enhancing effects of Lycium barbarum extracts involve multiple complex mechanisms, primarily including energy metabolism, oxidative stress regulation, lactate metabolism, and immune modulation.

3.1 Enhancement of Energy Metabolism

Liver and muscle glycogen serve as the primary energy sources during physical activity. When glycogen stores are depleted, insufficient energy supply can lead to fatigue. Lycium barbarum polysaccharides (LBPs) can activate enzymes involved in glycogen synthesis, thereby promoting glycogen accumulation and storage in both the liver and skeletal muscle. Animal studies have demonstrated that mice supplemented with goji berry extracts show significantly higher hepatic glycogen levels and a more than 20% increase in exhaustive swimming time compared with controls, highlighting their role in sustaining energy supply during exercise.

3.2 Antioxidant Effects

During exercise, increased aerobic metabolism generates large amounts of reactive oxygen species (ROS). Excessive ROS can attack cell membrane phospholipids, trigger lipid peroxidation, cause cellular damage, and contribute to fatigue. Components in goji berry extracts, including polysaccharides and flavonoids, act synergistically to upregulate antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px). This enhances the body’s ROS-scavenging capacity, reduces the accumulation of lipid peroxidation products such as malondialdehyde (MDA), and mitigates oxidative damage that can impair exercise performance.

3.3 Regulation of Lactate Metabolism

During high-intensity exercise, skeletal muscles often rely on anaerobic metabolism due to insufficient oxygen supply, leading to substantial lactate production and accumulation in the blood and muscles. Lactate buildup lowers muscle pH, interferes with enzyme activity, and stimulates nerve endings, resulting in muscle soreness and fatigue. Lycium barbarum polysaccharides can activate lactate dehydrogenase, the enzyme that catalyzes the conversion of lactate to pyruvate for entry into aerobic metabolism, thereby accelerating lactate clearance from the bloodstream. Experimental evidence shows that post-exercise supplementation with goji berry extracts can reduce peak blood lactate levels by 15–20%, effectively alleviating fatigue symptoms.

3.4 Modulation of Immune Function

Prolonged intense exercise can induce “exercise-induced immunosuppression,” characterized by decreased activity of immune cells such as natural killer (NK) cells and T lymphocytes, as well as imbalances in cytokines like interleukin-2 (IL-2) and tumor necrosis factor-α (TNF-α), which increase susceptibility to infection. Goji berry extracts can modulate immune signaling pathways, enhancing NK cell cytotoxicity and T lymphocyte proliferation, while regulating IL-2 (promoting immune cell activation) and TNF-α (suppressing excessive inflammation) secretion. This helps maintain immune homeostasis following exercise.

4. Evidence from Animal and Cellular Studies

4.1 Animal Studies

At the animal level, multiple randomized controlled studies in mice have confirmed the anti-fatigue effects of Lycium barbarum extracts. In endurance assessments, mice orally administered varying doses of goji berry extract exhibited significantly prolonged exhaustive swimming times compared with saline-treated controls, showing a clear dose-dependent effect and directly demonstrating enhanced overall exercise endurance. Biochemical analyses further revealed that treated mice had markedly higher hepatic glycogen stores, along with reduced blood lactate and blood urea nitrogen levels, indicating improved energy utilization and metabolic efficiency. In addition, antioxidant evaluations showed that goji berry extracts upregulated the activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px), while reducing levels of malondialdehyde (MDA), a marker of lipid peroxidation. These findings provide mechanistic support for the anti-fatigue effects of goji berry extracts through the modulation of oxidative stress.

4.2 Cellular Studies

Cellular studies have further elucidated the molecular mechanisms underlying the anti-fatigue effects of Lycium barbarum extracts. In oxidative damage models of skeletal muscle or liver cells induced by hydrogen peroxide (H₂O₂), supplementation with goji berry extracts significantly increased cell viability. This protective effect is achieved by reducing reactive oxygen species (ROS) accumulation and inhibiting lipid peroxidation, thereby mitigating oxidative stress-induced damage to cellular structures and functions, consistent with the antioxidant effects observed in animal studies. Moreover, goji berry extracts have been shown to modulate the expression of energy metabolism-related genes such as AMPK and PGC-1α. This regulation promotes the functional recovery of damaged mitochondria and enhances energy metabolism efficiency, providing a cellular-level explanation for how the body maintains energy supply during exercise and delays the onset of fatigue.

5. Evidence from Clinical Studies

Although clinical research on Lycium barbarum extracts remains preliminary, with limited sample sizes and study depth, existing trials suggest promising potential in alleviating fatigue and supporting exercise-related health. In a randomized controlled study involving healthy volunteers, daily supplementation with goji juice for four weeks significantly reduced subjective fatigue scores, mitigated post-exercise lethargy, and improved overall well-being, providing initial clinical support for its anti-fatigue effects. In the context of exercise, small-scale clinical trials have shown similarly encouraging trends. Goji supplementation was reported to enhance participants’ exercise endurance, accelerate post-exercise recovery, and reduce both the incidence and severity of delayed-onset muscle soreness (DOMS). Observations in athlete populations further indicated that goji intake helps maintain immune function following high-intensity exercise and attenuates exercise-induced inflammatory responses, offering valuable implications for health maintenance in physically active individuals.

6. Safety and Appropriate Use

As a traditional food-medicine dual-use plant, goji berries are generally considered safe for long-term consumption. Current research indicates that within conventional dosage ranges—typically 10–30 g of dried fruit per day or an equivalent amount of extract—goji consumption is overall well tolerated. However, isolated reports have noted that some individuals may experience mild gastrointestinal discomfort or allergic reactions, highlighting the need to consider individual variability in certain populations. Additionally, certain constituents of goji berries may interact with medications. For example, studies suggest that goji intake could affect the metabolism and efficacy of anticoagulants such as warfarin. Therefore, caution is warranted when using goji or its extracts during pharmacotherapy. For exercise-related health interventions and routine wellness applications, dosages should be tailored based on population characteristics, exercise intensity, and individual health status. Monitoring for potential adverse effects is recommended to ensure the safe and effective use of goji berries in alleviating fatigue and enhancing exercise performance.

7. Conclusion and Future Perspectives

Lycium barbarum extracts show considerable potential for alleviating fatigue and promoting exercise-related health. Their mechanisms of action include enhancing energy metabolism, scavenging reactive oxygen species, facilitating lactate metabolism, and modulating immune function. A substantial body of animal and cellular studies provides strong evidence for these anti-fatigue effects, while preliminary clinical trials have also reported encouraging outcomes. Nevertheless, current research has several limitations. Clinical studies remain small and of limited quality, the specific roles and synergistic interactions of different bioactive components are not yet fully understood, and variations in efficacy across different exercise types and populations require further evaluation. Additionally, the long-term safety and dose-response relationships need to be clarified. Future research should integrate approaches from nutrition, exercise physiology, and omics technologies to investigate L. barbarum extracts comprehensively—from molecular mechanisms to clinical applications and functional food development. Such multi-level exploration will advance the scientific use and industrial development of goji berry extracts in the field of exercise health.

Reference

[1] Peng Y, Zhao L, Hu K, et al. Anti-fatigue effects of Lycium barbarum polysaccharide and effervescent tablets by regulating oxidative stress and energy metabolism in rats[J]. International Journal of Molecular Sciences, 2022, 23(18): 10920..

[2] Vidović B B, Milinčić D D, Marčetić M D, et al. Health benefits and applications of goji berries in functional food products development: A review[J]. Antioxidants, 2022, 11(2): 248.

[3] Zhou X, Xu S, Zhang Z, et al. Gouqi-derived nanovesicles (GqDNVs) inhibited dexamethasone-induced muscle atrophy associating with AMPK/SIRT1/PGC1α signaling pathway[J]. Journal of Nanobiotechnology, 2024, 22(1): 276.

[4] Antonelli M, Donelli D. Health-promoting effects of goji berries (Lycium barbarum): A Literature Overview[C]//Biology and Life Sciences Forum. MDPI, 2024, 40(1): 1.

[5] Liu Y, Feng Z, Hu Y, et al. Polysaccharides derived from natural edible and medicinal sources as agents targeting exercise-induced fatigue: A review[J]. International Journal of Biological Macromolecules, 2024, 256: 128280.