Rebecca TaylorSir Mo Farah, Britain's four-time Olympic gold medallist, returned to screens on 6 April 2026 as a contestant on I'm A Celebrity All Stars South Africa — a show that throws celebrities into gruelling physical and psychological challenges in the African wilderness. At 43, Farah faces trials designed to push contestants to their physical limits. But what do extreme challenges like these actually reveal about the ageing body — and what lessons can the rest of us draw?
What I'm A Celebrity All Stars Puts Bodies Through
The I'm A Celebrity format, now in its second All Stars series on ITV, involves sleep deprivation, reduced caloric intake, extreme temperatures, and tasks requiring bursts of physical exertion and mental endurance. Previous contestants have described significant weight loss, muscle deterioration, and psychological strain within just days of arrival.
For Mo Farah, whose career spanned three Olympic Games and who retired from competitive athletics in 2023, the transition from elite training to more moderate activity followed by a return to extreme stress is medically significant. According to research published by the British Journal of Sports Medicine, former elite endurance athletes over 40 experience a more pronounced reduction in VO2 max — the body's capacity to use oxygen during exercise — compared to recreational athletes at the same age, largely because their starting point was so much higher.
Put simply: the drop is steeper when you start at the top.
The Over-40 Physiology Gap
For the millions of recreational runners and fitness enthusiasts inspired by athletes like Mo Farah, understanding the physiological changes that occur after 40 is genuinely useful — and often misunderstood.
Muscle mass decline (sarcopenia) begins in earnest from around age 35, accelerating after 50. Without targeted resistance training, adults lose roughly 3-5% of muscle mass per decade. For endurance athletes, this affects not just speed but injury resilience: muscle acts as a shock absorber for joints and tendons.
Cardiovascular recovery time increases. After intense exercise, the heart and vascular system take longer to return to baseline. This is normal, but ignoring it leads to overtraining — one of the most common reasons recreational athletes over 40 end up seeing a GP or sports medicine specialist.
Hormonal shifts — declining testosterone in men, changing oestrogen levels in women — affect bone density, fat distribution, and the body's inflammatory response to exercise. A 43-year-old training hard without understanding these changes risks stress fractures, tendinopathy, or chronic fatigue.
Nutrition needs change. Protein requirements actually increase with age to support muscle repair. A 40+ athlete eating the same diet as they did at 25 may be under-fuelling recovery without realising it.
When Should You See a Health Professional?
Mo Farah has the support of a professional coaching and medical team. Most people over 40 who take up or maintain sport do not.
A GP with an interest in sports medicine, or a specialist in exercise medicine, can offer:
- A baseline health assessment — cardiovascular screening, blood pressure, glucose metabolism and cholesterol levels — before intensifying a training programme
- Personalised advice on training load, rest periods, and injury prevention tailored to your current fitness level and medical history
- Guidance on nutritional supplementation, including vitamin D (critical for bone health and immune function), protein intake, and creatine, which has robust evidence for muscle preservation in older adults
- A referral pathway if imaging or specialist input is needed — for example, an orthopaedic assessment for a persistent knee or hip issue before it becomes a serious injury
The NHS guidance on exercise for adults over 40 recommends at least 150 minutes of moderate-intensity aerobic activity per week, combined with muscle-strengthening activities on two or more days — a baseline that sports health experts can help you build towards safely.
The Mental Health Dimension
I'm A Celebrity is as much a psychological test as a physical one. Mo Farah, who has spoken publicly about difficult aspects of his childhood — including being brought to Britain illegally as a child — has a complex relationship with resilience and identity. The show strips away routine, comfort, and control.
For everyday people facing their own version of this — stressful work periods, life transitions, grief, or long-term illness — the link between physical health and mental wellbeing is increasingly well-documented. Exercise has been shown in multiple large-scale NHS studies to reduce symptoms of anxiety and depression, but only when the physical load is sustainable. Pushing too hard, too fast, can tip the balance the other way.
A health professional who understands both the physical and psychological dimensions of fitness — including GPs, sports psychologists, and physiotherapists — can help you build a programme that strengthens both body and mind.
Inspired by Mo Farah? Start With the Right Support
Whether you're returning to exercise after a break, training for your first half marathon, or simply want to stay active and well into your 40s, 50s, and beyond, a conversation with a health professional is the smartest first step — not the last resort.
ExpertZoom connects you with GPs, physiotherapists, nutritionists, and sports medicine specialists across the UK who can advise on staying healthy, active, and injury-free — whatever your starting point.
Disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult a qualified health professional before starting or significantly changing an exercise programme.
