INTRODUCTION

The human skin is inhabited by a diverse and dynamic population of microorganisms that collectively constitute the skin microbiome. This community includes bacteria, fungi, viruses, and mites that occupy different ecological niches across the skin’s surface. These microbial inhabitants are not merely commensals; rather, they perform critical functions in protecting the host from pathogenic colonization, educating the immune system, and maintaining homeostasis of the cutaneous barrier [1,2].

In the context of athletic performance, the skin is not only a mechanical barrier but also a dynamic interface exposed to a range of physical, chemical, and microbial stressors. Sweating, friction from clothing and equipment, exposure to different environmental conditions, and repetitive cleansing practices all contribute to transient and sometimes chronic changes in the microbiota. These factors are often intensified in high-performance athletes who maintain rigorous training schedules and undergo frequent environmental exposures, including chlorinated pools, open fields, and shared equipment [3,4].

Despite increasing research into the gut microbiome in relation to physical performance, relatively limited attention has been directed toward the skin microbiome in athletic populations. This gap is critical, as changes in the microbial environment of the skin may not only predispose individuals to infections but also modulate inflammatory responses, delay recovery, and affect performance indirectly [5,6].

Recent studies have highlighted that microbial dysbiosis in athletes may increase susceptibility to a range of dermatological conditions, including folliculitis, acne mechanica, tinea corporis, and colonization by methicillin-resistant Staphylococcus aureus (MRSA). Understanding how training conditions, personal hygiene habits, and environmental exposures shape the skin microbiome is essential for developing effective preventive and therapeutic approaches tailored to athletes [7,8].

This review aims to consolidate the current body of knowledge on the skin microbiome in athletes, elucidating its composition, susceptibility to disruption, and clinical consequences. In addition, we explore evidence-based strategies to preserve microbial balance and reduce dermatological complications in sports settings [9].

MICROBIOME COMPOSITION AND PHYSIOLOGY IN ATHLETES

The composition of the skin microbiome in athletes is determined by complex interactions between endogenous factors, such as skin type and gland distribution, and exogenous influences including physical exertion, clothing, hygiene practices, and environmental exposures. The core microbiome is generally dominated by four main bacterial phyla: Actinobacteria, Firmicutes, Proteobacteria, and Bacteroidetes. These taxa are differentially distributed across body sites, with sebaceous regions typically colonized by lipophilic species such as Cutibacterium acnes, and moist regions dominated by Staphylococcus and Corynebacterium species [10].

Athletic activity often intensifies the conditions that influence microbial composition. Increased sweating alters the skin’s pH and salinity, creating an environment that selectively favors certain microorganisms over others. For instance, occlusive clothing and prolonged moisture retention promote the proliferation of Gram-positive bacteria and yeast such as Malassezia spp., which may lead to dysbiosis in susceptible individuals [11].

Sport-specific differences have been documented in the microbial composition of athletes. Endurance runners exhibit increased microbial diversity post-exercise, while swimmers show greater abundance of chlorine-tolerant organisms and transient depletion of resident commensals such as Staphylococcus epidermidis. Contact-sport athletes, such as wrestlers and rugby players, are more frequently colonized by potentially pathogenic strains of Staphylococcus aureus due to skin-to-skin contact and environmental contamination through shared equipment [12,13].

Functional interactions between skin microbes and host immunity are increasingly recognized as integral to maintaining cutaneous health. Commensal bacteria contribute to the modulation of local immune responses, reinforce barrier function through metabolite production, and offer competitive resistance to pathogenic invasion. Disruption of these relationships through intense physical stress or inappropriate hygiene may impair skin integrity and delay wound healing [14].

Emerging research also highlights the impact of systemic factors—such as diet, hydration status, and recovery practices—on microbial diversity and resilience. Advances in metagenomic sequencing and bioinformatics have facilitated the characterization of microbial communities and their functional pathways, enabling deeper insights into the adaptive nature of the skin microbiome under athletic stress [15].

DISRUPTIVE FACTORS: PHYSICAL ACTIVITY, SWEAT, CLOTHING, AND ENVIRONMENT

Athletic training environments expose the skin to mechanical, chemical, and microbial stressors that can disrupt the natural composition of the microbiome. Among these, physical activity itself is a major determinant of microbial alterations due to increased perspiration, frictional stress, and temperature shifts. Sweat, although crucial for thermoregulation, alters the skin’s pH and hydration level, promoting the growth of certain microbial taxa while inhibiting others [16].

The composition of sweat includes water, salts, amino acids, and antimicrobial peptides, which collectively impact microbial colonization. While eccrine glands primarily excrete salt-based fluids, apocrine secretions in areas such as the axillae and groin are rich in lipids and proteins, serving as substrates for specific bacteria. This results in a shift in microbial ecology, often promoting the growth of Corynebacterium and Staphylococcus species, which can lead to body odor and skin irritation [17].

Synthetic, tight-fitting athletic apparel often exacerbates these conditions. Prolonged occlusion increases local humidity and temperature, leading to microclimatic environments that favor yeast proliferation, particularly Malassezia. These conditions can also cause friction-induced damage to the stratum corneum, weakening the skin barrier and allowing opportunistic pathogens to colonize deeper layers. This is especially relevant in sports involving repetitive movements, such as cycling or rowing [18,19].

Environmental factors further contribute to microbial imbalance. For instance, chlorinated pool water can reduce skin microbial diversity and disrupt lipid bilayers, while contact with grass, soil, or shared gym surfaces introduces transient microbes that may displace commensals or introduce pathogenic strains. UV radiation exposure and ambient air pollutants have also been implicated in microbial shifts that compromise skin barrier integrity [20].

Inadequate hygiene practices—such as the overuse of antimicrobial soaps, failure to change athletic clothing promptly, or infrequent cleansing of gear—can exacerbate these effects. Such behaviors may lead to selective pressure on the skin microbiota, fostering resistant organisms and contributing to recurring dermatological issues in competitive athletes [21].

DERMATOLOGICAL RISKS AND CLINICAL MANIFESTATIONS

Athletes are predisposed to a variety of dermatological conditions due to repeated mechanical irritation, excessive sweating, and microbial dysbiosis. Among the most common disorders is acne mechanica, a subtype of acne vulgaris that results from friction, pressure, and occlusion by equipment or tight clothing. This condition is frequently observed in contact-sport athletes, cyclists, and martial artists [22].

Another prevalent issue is folliculitis, the inflammation of hair follicles, which can be caused by bacterial agents such as Staphylococcus aureus or by fungal organisms including Malassezia spp. Folliculitis is often exacerbated by occlusive gear, damp clothing, and improper hygiene. In more severe cases, it may progress to furuncles or carbuncles, requiring systemic antibiotic treatment [23].

Tinea corporis and tinea pedis, caused by dermatophytes like Trichophyton rubrum, are highly contagious fungal infections commonly seen in athletes. These infections thrive in moist environments such as locker rooms, shared showers, and footwear. Wrestlers and swimmers are particularly susceptible due to frequent skin contact and exposure to communal surfaces [24].

Colonization and infection with methicillin-resistant Staphylococcus aureus (MRSA) have emerged as a serious concern in team sports. MRSA can be transmitted via direct contact or contaminated equipment and may lead to abscesses, cellulitis, or even systemic infections. Preventive measures such as screening, decolonization protocols, and strict hygiene are essential to reduce its spread in athletic populations [25].

In addition to infectious conditions, athletes may experience contact dermatitis from adhesives, detergents, or topical products used during training or rehabilitation. These reactions can compromise skin barrier function, exacerbate microbial imbalances, and increase the risk of secondary infections [26].

Proper diagnosis and timely intervention are crucial to mitigate complications and avoid disruptions to training schedules. Dermatological assessments should be integrated into routine medical evaluations for athletes, particularly those in high-risk disciplines. Furthermore, increased awareness and education on skin care practices can empower athletes to maintain optimal skin health and microbial balance [27].

STRATEGIES FOR PREVENTION AND MANAGEMENT

Given the complex interplay between physical exertion, environmental exposure, and microbial alterations, preventive strategies must be multifaceted and tailored to the needs of athletes. Central to maintaining skin health is the preservation of microbial diversity and integrity of the epidermal barrier [28,29].

Hygiene practices should focus on moderation rather than eradication of microbes. Overuse of antiseptic soaps and antibacterial agents can disrupt commensal populations, creating ecological niches for opportunistic pathogens. Instead, athletes should be advised to use gentle, pH-balanced cleansers that support the skin’s natural microbiota [30].

Post-exercise routines should include prompt showering with lukewarm water, thorough drying—especially in intertriginous zones—and the use of clean, breathable clothing. Footwear should allow ventilation, and socks should be made of moisture-wicking materials. Personal items such as towels, razors, and protective gear must not be shared [31].

In high-risk environments like wrestling mats or communal gym equipment, routine disinfection and adherence to hygiene protocols are essential. Coaches and staff should be trained to recognize early signs of infection and implement isolation or treatment measures where necessary. Educational programs can enhance awareness and compliance among athletes [32].

Emerging microbiome-friendly interventions, including topical probiotics, postbiotic formulations, and prebiotic skincare, show promise in restoring balance to dysbiotic skin. These approaches aim to reintroduce beneficial bacteria, enhance antimicrobial peptide expression, and promote skin barrier recovery after disruption [33,34].

Regular dermatological screening—particularly in contact sports—can identify subclinical conditions and inform early management. Collaboration between dermatologists, sports physicians, and trainers is critical for developing individualized care protocols that integrate both performance and health considerations [35].

DISCUSSION

The findings presented in this review underscore the intricate relationship between athletic lifestyle and skin microbiome dynamics. While physical activity confers numerous health benefits, it also imposes stressors on the skin that can compromise microbial equilibrium and barrier function. The balance between commensal and pathogenic organisms is highly sensitive to sweat composition, hygiene behavior, and material occlusion. [36].

One of the central challenges lies in differentiating between normal fluctuations in microbial composition and pathological dysbiosis. Athletic individuals may exhibit transient shifts that reflect physiological adaptation rather than disease. However, when compounded by environmental insults or improper hygiene, these shifts may become maladaptive and contribute to dermatological morbidity [37–40].

The role of the skin microbiome in immune regulation, inflammation control, and wound healing is increasingly appreciated. Disruptions to microbial communities not only elevate the risk of infections but may also prolong tissue recovery and impair barrier repair. This is particularly relevant in high-intensity training and contact sports, where skin abrasions are common and recovery windows are short.

Interventions that preserve microbial diversity and support commensal populations are likely to confer both protective and performance-related advantages. The emergence of microbiome-aware dermatological formulations represents a promising shift toward sustainable and individualized skin care for athletes.

Nonetheless, there remain gaps in the literature regarding long-term microbial trends across seasons, training phases, and athletic disciplines. Future research should aim to establish baseline microbial profiles for different sports and explore how nutrition, climate, and training load intersect with skin ecology. Randomized controlled trials assessing the efficacy of microbiome-based therapies in sports dermatology are warranted to validate their clinical utility.

CONCLUSIONS

The skin microbiome represents a critical yet underappreciated component of athlete health. As demonstrated throughout this review, physical activity, environmental exposures, and personal hygiene practices interact to shape microbial communities, influencing dermatological outcomes and potentially affecting overall performance.

Maintaining the integrity of the skin barrier and its microbiota requires strategic prevention tailored to the athletic context. Emphasis should be placed on education, evidence-based hygiene, and the integration of microbiome-supportive products and practices. Early identification and management of dysbiosis-related conditions can mitigate complications and enhance recovery time.

Future investigations should prioritize longitudinal studies that map microbial changes across training periods and disciplines. Additionally, randomized trials are needed to assess the real-world efficacy of novel microbiome interventions. Personalized strategies that account for individual variability in microbiome composition and lifestyle factors may represent the next frontier in sports dermatology and performance optimization.

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