Physical Activity and Skin Ageing: Dermal Remodelling, Exerkine Signalling and Functional Skin Outcomes

This research project examines the relationship between physical activity and skin ageing, with a particular focus on whether exercise can influence dermal remodelling, myokine/exerkine signalling, microvascular function, epidermal barrier performance and measurable skin functional outcomes. Skin ageing is usually discussed in relation to topical skincare, photoprotection, cosmetic procedures and intrinsic chronological ageing, but the skin is also a metabolically active, vascularised and immune-responsive organ. This project investigates whether systemic physiological adaptations induced by exercise may contribute to healthier skin ageing. The central purpose of the project is to map and critically evaluate the available evidence on the proposed muscle–skin axis. This includes direct human studies examining exercise and skin outcomes, supportive human studies on skin hydration, elasticity, perfusion and appearance, and mechanistic studies exploring pathways such as IL-15/AMPK signalling, inflammatory regulation, mitochondrial metabolism, extracellular-matrix organisation and exercise-induced systemic signalling. The review distinguishes between what is directly supported by human intervention evidence and what remains mechanistically plausible but unproven. The project is structured as a PRISMA-ScR-informed scoping review, using a tiered evidence framework to classify studies according to evidentiary strength. Tier 1 includes direct controlled human exercise–skin intervention evidence; Tier 2 includes supportive human studies with skin-related functional or appearance outcomes; Tier 3 includes translational, animal or mechanistic studies relevant to exercise-induced skin biology; and background sources are used only to support broader concepts, not as primary evidence-map studies. This structure is designed to avoid overclaiming while still capturing the breadth of an emerging and interdisciplinary field. The expected outcome of the project is a clearer, evidence-based understanding of what physical activity may actually do for skin ageing. Current evidence suggests that exercise is unlikely to act as a simple cosmetic “anti-ageing” treatment that directly regenerates collagen or elastin in all contexts. Instead, exercise may help create a more favourable systemic environment for skin health by improving dermal extracellular-matrix regulation, vascular support, mitochondrial metabolism, inflammatory balance and metabolic resilience. Resistance training appears most relevant to dermal structure and extracellular-matrix support, while aerobic/endurance exercise appears particularly relevant to mitochondrial and vascular pathways. A further expected outcome is the identification of major research gaps. These include limited numbers of controlled human trials, small sample sizes, insufficient male and Fitzpatrick skin type diversity, limited biopsy or molecular endpoint data, inconsistent control of sun exposure and skincare routines, and inadequate long-term follow-up. The project therefore proposes a future trial framework incorporating dermal ultrasound, cutometry, corneometry, TEWL, skin imaging, perfusion measurement, myokine panels, inflammatory biomarkers and standardised control of confounders such as UV exposure, diet, sleep and topical skincare. Overall, this research aims to reposition physical activity as a scientifically plausible systemic modifier of skin ageing rather than merely a general wellness recommendation. The project is expected to contribute a structured evidence map, a refined conceptual model of the muscle–skin axis, and practical recommendations for future clinical trials investigating exercise as an adjunctive strategy in dermatology, aesthetic medicine and healthy ageing research.