From the magazine – Skin in Motion

In this excerpt from the Summer 2026 edition of International Therapist, Laura Jane Stonehouse explores how environmental factors affect the skin, and how to account for tough conditions during exercise.

For millions of years, in the scorching expanse of the Sahara, highly adapted desert plants have not just survived, but actively thrived in intense heat and relentless sunlight without the presence of water. These remarkable organisms have protected their cellular structures, enabling them to remain stable even under the most extreme physical conditions. In 1974, a NASA researcher named R.D. MacElroy introduced the term “extremophile” in a landmark paper to describe such plants. Today, these organisms have been adapted for use in advanced formulations to support the skin’s resilience under environmental stress.

There is a certain kind of synergy with this term and the endurance runner’s own relationship with extremes – not as something endured reluctantly, but as a chosen environment of challenge and adaptation, where resilience can only come from within.

THE RISE OF RUNNING AND ENDURANCE TRAINING

The surge in interest in endurance running reflects a shift in fitness culture, prioritising experiential, goal-driven, outdoor activities over traditional gym-based exercise. In 2025, the TCS London Marathon set a new world record with over 56,000 participants crossing the finish line, and over 1.1 million people entering the ballot for the 2026 event.

Trail running has also grown rapidly in popularity over the past decade as runners seek a more inspiring experience beyond roads and indoor training. Its rise has been fuelled by increased interest in outdoor fitness to support mental wellbeing alongside the influence of social media showcasing iconic routes and ultra-endurance events. Trail races attract both elite athletes and recreational runners to an activity that provides not just a high level of fitness but also the opportunity to embrace the freedom, exploration, and connection with nature that road running often lacks.

A RUNNER’S SKIN JOURNEY

The impact of long-distance running on facial appearance has long been debated, particularly the perception that repeated, long-term training may contribute to “runner’s face” – a term used to describe a gaunt appearance, loss of facial volume, and premature ageing. However, it is important to understand the underlying factors that influence skin health, and how these can be effectively managed.

THE TRAINING SCHEDULE

A marathon training schedule typically involves running most days of the week, covering around 80–130 km (50–80 miles), and can even involve completing two runs a day plus a weekly long run to build endurance. This high-volume approach, combined with resistance training, has been adopted by long-distance runners such as singer Harry Styles, who remarkably improved his marathon time to 2hrs 59m in Berlin from 3hr 24m in Tokyo.

While it is true that long-distance running potentially reduces facial fat because of the high-calorie deficit it causes, resistance training has become an integral part of endurance preparation and can help to preserve facial structure by creating muscle mass.

ENVIRONMENTAL EXPOSURE AND SKIN HEALTH

As endurance training involves prolonged time outdoors, this increases exposure to environmental stressors such as heat, wind, cold, and pollution. UV light can cause direct damage to the DNA within skin cells, triggering inflammation and accelerating skin ageing. When UV rays penetrate the skin, they can break DNA strands, thereby disrupting the signals that tell cells how to function properly. The visible signs of sun damage – such as fine lines, wrinkles, loss of elasticity, and pigmentation – are the result of damage deep within the skin.

This is why prevention is so important; correcting the effect is more difficult than protecting the skin in the first place. Repeated and unrepaired DNA damage also increases the risk of skin cancer.

DEHYDRATION

Ultra-endurance athletes are highly susceptible to dehydration due to prolonged training and competition – and cold weather can be just as dehydrating as heat. This is because cool air is normally quite dry. Every time you exhale, your body loses moisture as water vapour. In freezing conditions, that loss increases because your breath visibly condenses – meaning you’re literally exhaling water.

The body also triggers cold-induced diuresis; blood vessels in your skin constrict to conserve heat, which slightly increases your blood pressure. Your kidneys respond by producing more urine to reduce that pressure, thereby losing you fluids. The thirst response is also suppressed, even though the body is still losing water through perspiration, so an athlete is at risk of not drinking enough to replace lost fluids even in the cold. Chronic dehydration without adequate replenishment impairs the skin barrier by increasing transepidermal water loss (TEWL), which disrupts the natural renewal processes in the stratum corneum and compromises overall skin health.

ELECTROLYTES AND RISKS TO SKIN HEALTH

Electrolytes such as sodium, potassium, and magnesium play a vital role in maintaining skin health, by regulating hydration and supporting cellular function, which helps the skin stay plump and resilient. They are also an essential part of race and training nutrition to replace minerals lost through sweat, often alongside quick sources of glucose to maintain energy levels.

This is an abridged extract from a longer article. The full version can be found in the FHT members section of the FHT website.