Athletes are constantly plagued by injuries that can impair performance and hinder their ability to train. Nutrition and bioactive compounds can aid in tissue regeneration, delivering the appropriate building blocks for repair processes and attenuating oxidative stress and inflammation. Proper nutrition may even assist in mitigating injury by supporting recovery and tissue integrity. Low energy availability, micronutrient inadequacy, and poor hydration have all been linked with elevated injury incidence. Protein as well as vitamin C and zinc have been demonstrated to support healing and accelerate recovery in part due to their interaction with the immune system. The gut microbiome is also implicated in tissue regeneration as a key determinant of immune function. Finally, a variety of bioactive extracts from plants have been studied for their role in wound healing and tissue repair. Adopting a comprehensive approach to nutritional care is pivotal in sustaining athletic performance, promoting recovery, and alleviating injury risk.
Part 2: The impact of polyphenols and other nutrient compounds
Bioactives, including polyphenols and other nutrient compounds, exhibit important functional activities upon consumption. They have been explored in the context of sports performance and injury prevention owing to their antioxidant properties and ability to mitigate oxidative stress and subsequent peroxidation. Dampening of reactive oxygen species generation serves to insulate against tissue damage, thereby lessening inflammation. Their regulation of inflammatory cascades can enhance bone healing, protein synthesis, and muscle regeneration, as well as attenuate tissue breakdown during periods of immobilization or training cessation. Polyphenols are widely available in fruits and vegetables, and can also be derived from other living organisms such as bacteria, fungi, and algae. Adequate consumption of polyphenols additionally promotes redox homeostasis and mitochondrial function through modulation of metabolic processes. Polyphenols have been found to upregulate Nrf2 and PGC-1α/SIRT1 pathways while repressing NF-κB, and prompt expression of insulin-like growth factor I (IGF-I) and II (IGF-II) involved in tissue regeneration. These effects act to bolster antioxidant defense, inhibit stress-induced immune activation, limit muscle injury and tissue catabolism, and ameliorate energy metabolism and muscle function.
Omega-3 fatty acids sourced predominantly from fatty fish are commonly deficient in the athlete population. Omega-3 fatty acids, including eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), and docosahexaenoic acid (DHA) are well-appreciated for their role as neuroprotectants, anti-inflammatories, and immunomodulators. Healthy levels of omega-3 fatty acids are correlated with reductions in oxidative stress, inflammation, immune function, cardiovascular and cognitive health, as well as muscular performance. Omega-3 fatty acid supplementation may be most beneficial in cases of traumatic brain injury, attenuating pro-inflammatory cytokine production and subsequent neuronal damage. They have also been observed to inhibit microglial activation via their interaction with SIRT1 and related HMGB1/NF-kB. Omega-3 fatty acids appear to dampen NF-kB and the downstream IL-1b, IL-6, and TNF-a cytokines. Important to note is the altered bioavailability of differing forms of fatty acids, with phospholipids exhibiting the greatest absorption and tissue incorporation.
Vitamin C is a cofactor for prolyl and lysyl hydroxylases, enzymes implicated in connective tissue synthesis. Vitamin C is also well-known for its antioxidant potential. It has thus been studied as an adjunct therapeutic in brain injury as well as tendon, bone, and connective tissue healing. Collectively, vitamin C serves to diminish oxidative stress and correlated lipid peroxidation, minimize reactive oxygen species generation and pro-inflammatory cytokines, support endothelial and connective tissue health, and participate in muscle repair and regeneration.
Vitamin D acts as a pro-hormone in the regulation of calcium and phosphorus balance, energy metabolism, immune function, inflammation, protein synthesis, muscle regeneration, and cell growth. Many athletes are deficient in the vitamin, exacerbating injury risk and inflammation. Low vitamin D status has been associated with compromised bone and muscle integrity, as well as poor sports performance. Supplementation has been noted to improve power, strength, and endurance, and protect against fractures. Combing vitamin D with calcium may reduce markers of bone turnover and thus further support bone density.
Magnesium, in addition to calcium and phosphorus, is a key component of bone. Magnesium is an obligate activator of vitamin D, and the two collaborate to improve calcium GI uptake and bone retention, as well as osteoblastic activity. Magnesium is hugely influential in energetic processes as a requirement for ATP synthesis, and behaves as a cofactor in hundreds of enzymatic reactions. Moreover, magnesium attenuates oxidative stress and inflammation while boosting myogenesis and glucose utilization. Adequate magnesium can buffer against accumulation of lactate to support endurance performance. Ensuring sufficient magnesium in the diet is important for preserving energy utilization and production, bone integrity, and muscle performance.
Amino acids are also necessary to drive insulin production and the anabolic response that promotes tissue accretion. L-carnitine can be endogenously synthesized in the liver, kidney, and brain, but is also present in meat products. L-carnitine acts as a long-chain fatty acid carrier, transporting fats into the mitochondrial matrix for oxidation. As fats are a preferred fuel source for the brain, L-carnitine has been recommended post-brain injury to diminish oxidative stress and conserve tissue integrity. It may also encourage mitochondrial biogenesis and mitigate accumulation of mitochondrial DNA damage. These affects are purportedly related to L-carnitine’s involvement in the PTEN/Akt/mTOR and Nrf2/ARE signaling pathways implicated in oxidative stress, as well as axonal plasticity and myelination.
Creatine is one of the most well-studied ergogenic aids demonstrated to improve muscular strength and endurance. Creatine, like L-carnitine, is endogenously synthesized from the amino acids glycine, arginine, and methionine, and is available in meat products. Creatine is a pivotal component of the phosphocreatine-ATP energetic system involved in production of power, and also stimulates GLUT4 translocation for glucose uptake. Creatine stimulates muscle mass accrual and may thus assist in muscle regeneration following injury or damage. Creatine raises cellular hydration which may engender an anabolic effect, while modification of myogenic transcription factors and IGF-1 further prompts muscle cell development. Creatine appears to protect against muscle catabolism by suppressing TNF-a, IL-6, Atrogin-1, and MuRF-1.
Collagen, composed of glycine, proline, and hyroxyproline, is essential for connective tissue integrity. Collagen peptide supplementation may enhance cell division, collagen synthesis, and development of the extracellular matrix. Collagen intake has been shown to increase tendon function and cross-sectional area, muscle growth and muscle strength, and bone metabolism and density. Collagen also seems to ameliorate joint function and diminish inflammation. Collagen pairs well with vitamin C, an essential cofactor, as well as vitamin D and calcium. It has been implicated in the expression of Runx2, a bone transcription factor, as well the blockage of the TGF-β/myostatin pathway involved in muscle catabolism. Collagen further enhances muscle protein synthesis by stimulating the PI3K/ATK/mTOR and MAPK pathways.
Collagen production and tissue healing are also regulated by nitric oxide, the synthesis of which is dependent on the availability of L-arginine. L-arginine additionally functions in the urea cycle, bone metabolism, and angiogenesis through the modulation of mitochondrial PINK1/Parkin expression and osteoblast Bnip3, alkaline phosphatase, Runx2, and osteopontin expression. L-arginine may exert anti-inflammatory and antioxidant properties, and regulate autophagic flux during the healing process. Stress and trauma both upregulate the need for arginine and glutamine due to their involvement in immune function, cell division, and tissue regeneration.
Glutamine is another amino acid heavily implicated in immune, inflammatory, and healing processes. Glutamine is the most abundant endogenous amino acid and is a key energy source for lymphocytes and fibroblasts. Glutamine behaves as an immunomodulator through its influence on IgA and NO concentrations. It additionally prevents muscle atrophy and boosts muscle cell development by inhibiting TNF-a-triggered p38 MAPK activation. In the context of athletics, glutamine supplementation has been observed to attenuate fatigue and ammonia accrual while augmenting glycogen synthesis, thereby potentiating sports performance. It also represses IL-6, TNF-a, and CRP that otherwise induce an inflammatory response which can interfere with tissue regeneration.
Another key ergogenic aid is leucine, a branched-chain amino acid valued for its anabolic potential through mTOR and AMPK activation. Both of these pathways stimulate muscle protein synthesis and amplify energy metabolism. Leucine also modifies NF-kB, MAPK, and JAK/STAT that otherwise prompt release of inflammatory factors like TNF-a and IL-6.
Chronic sports injuries can impair performance, hinder the ability to train, and sideline athletes for prolonged periods. They can additionally severely impact quality of life, mental health, and professional endeavors. A comprehensive nutritional approach is pivotal in supporting an athlete’s overall health through periods of vigorous training, travel, and injury. Adequate nutrition and appropriately used nutritional supplements can mitigate the detriments of immobilization, promote recovery, and accelerate return to activity. Nevertheless, biotics and bioactive compounds lack robust clinical evidence detailing their safe and effective implementation. Careful consideration should be undertaken prior to their recommendation that includes athlete characteristics and nutritional status, inter-individual variability, clinically supported dosages and forms, appropriate combinations, and time-dependent effects.
Şahin-Demirci K, Dal N, Gönen-Çolak B, Akman O, Raposa B, Ağagündüz D. The role of biotics and bioactive compounds in sports injuries: a narrative review. Front Nutr. 2026;13:1813030. Published 2026 May 14. doi:10.3389/fnut.2026.1813030