I didn't realise it then but I heard about contrast therapy 25 years ago when a patient of mine received advice from a GP in another practice. “Skeptical” doesn't describe my reaction.
Much later I discovered that its been in use in Alpine spas to aid recovery of sore legs in walkers.I’m a full on convert now.
So as always with these blogs - what's hype and where’s the truth?
Exposure to increased heat causes a number of physical changes such as increased blood flow to skin and a mild stress response. Heart rate increases.Its a bit like gym without the weights.
Heat Shock Proteins are released and have some pretty cool effects - by adapting the body to heat, it's similar to mild cardio exercise
HSPs also help reduce muscle loss (sarcopenia) which happens with age - a
Studies in Finland showed regular sauna users had increasing benefits the more they did - up to the highest in those using 4-7 times a week a whopping 50% reduction in fatal cardiovascular disease.
Reduced blood pressure was related to blood vessels being less stiff. The lining of the blood vessels improved as well
Cold therapy is another form of mild stress. Our cells respond to stressors by developing resilience - they respond better to challenges. Alternating these seems to increase the effects of adaptation to stress.
Staying in the UK at the moment meant I didn't have access to my usual sauna and cold pool - but showers there are - 90 seconds in the cold is enough to produce the effects, followed by a few minutes of hot.
Finish on cold. As well as feeling a boost from the hormones released, repeated use will boost the immune system
Tag: health
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Contrast Therapy: The Hot & Cold Truth
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A strange event on a British beach that made me look deeper into biology!
As I stood looking out to sea, braced by the iron railings against the winds coming in from the North East (the direction of Siberia). To the poms this is called “blustery weather”, to the rest of the world its bloody freezing when a half sane person wouldn’t be taking off an overcoat. But I witnessed a group traversing the beach towards a foaming sea the colour and menace of steel. The bonds of comradery suggested a religious fervour – the surface they were crossing appeared like a carpet of stone fruits – without the fruit. There must be some great reward awaiting.
As their bodies were embraced by the waters, someone to my side muttered an explanation – ‘cold water swimming’
And so, my deep dive into cell biology, and the explanations of how our cells need to clean and recycle proteins. If they don’t, these build up over years like belonging in a hoarders house. Unchecked this contributes to faster aging and many of the chronic diseases we notice in older people. The clean-up is called “autophagy” and the research into how it happens has grown exponentially in the last 10 years. It doesn’t need to be as extreme as cold water swimming in Cromer, but we can gain important learning. -

Longevity Unlocked: How to Age Better
Does raw garlic have any special properties - this is the response I gave to this question posed to me
Alliums in general are of interest because of their effects on the Microbiome, being a good source of resistant starch and promoting bacterial populations that produce SCFA (short chain fatty acids) These chemicals have a direct antiinflammatory effect.
Cancer prevention is a broad topic and many of the things we can do already have clear benefits including maintaining a healthy body weight and exercise.
The failing of the innate immune system is widely thought to lead to less effective apoptosis (rogue cell destruction) and autophagy (cell cleaning ) and indirectly there to cancer risk
Known promoters of autophagy are related as they are hormetics, that is they are mild stressors to the cellular environment and cells enter into a protein recycling pathway which makes the cells healthier
1 Heat. Sauna use 3-4 times a week.
2 Cold. Short exposure (90 seconds ) in cold water - daily if possible
3 Fasting. Intermittent fasting 14-16 hours at regular intervals
4 High Intensity exercise. Short bursts of HIIT 2-3 times a week
5 Certain plant chemicals such as chilli, black pepper, ginger, turmeric
6 A glycoprotein from plants also found in human tissues called Spermidine. Some evidence that boosting levels mimics the autophagy effects of fasting
Maintaining a healthy gut environment seems to be very beneficial and is helped with a diet containing a variety of seeds, nuts and vegetables. The healthy gut assists preservation of immune health
Additionally, maintaining a stable blood sugar response appears to be very important in reducing cellular damage
I've done a bunch of tests myself to optimise my health. The best piece of advice I read was from Prof In Newcastle UK who said to be healthy in old age you need to be in the same size trousers as you were at college !
You know what they say about aging. Middle age is when a broad mind and narrow waist change places.
The “3 horseman” diseases of age are cancer, cardiovascular disease and cognitive decline - there are other important issues as well such as osteoenia (weakening of bones) sarcopenia (loss of muscle strength) - but for the key 3 determining risk helps, and we know enough about the risks for these to take a course correction now, particularly if any of our risks are higher than average -

Microbiome changes with spices & peanuts
For the peanut study, which was published in the journal Clinical Nutrition, Kris-Etherton and her colleagues compared the effects of snacking on 28 grams (approx. 1 ounce) of peanuts per day, versus a higher carbohydrate snack—crackers and cheese. At the end of six weeks, participants who ate the peanut snack showed an increased abundance of Ruminococcaceae, a group of bacteria linked to healthy liver metabolism and immune function.
In the herbs and spices study, which was published in The Journal of Nutrition, scientists analyzed the impact of adding blends of herbs and spices — such as cinnamon, ginger, cumin, turmeric, rosemary, oregano, basil, and thyme — to the controlled diets of participants at risk for cardiovascular disease. The team examined three doses — about 1/8 teaspoon per day, a little more than 3/4 teaspoon per day, and about 1 1/2 teaspoon per day. At the end of four weeks, participants showed an increase in gut bacteria diversity, including an increase in Ruminococcaceae, most notably with the medium and high doses of herbs and spices.
A global study involving over 50,000 participants links the presence of gut Blastocystis, traditionally seen as a parasite, with improved cardiovascular health and reduced body fat, suggesting beneficial effects on cardiometabolic health. Further research is required to validate these findings. -

Why My Drinking Patterns Changed After Learning About Longevity
As wine lovers, we often rave about the health benefits of a good red. But today, I want to talk about oranges—not wine.
For years, I believed that starting my day with a fresh glass of orange juice, packed with Vitamin C, was great for my health. However, after wearing a blood sugar monitor for a day, I discovered something surprising—downing a sugary drink on an empty stomach (even if it’s “natural sugar”) causes a sharp spike in blood sugar, followed by a crash.
This rollercoaster effect has serious implications, affecting energy levels and potentially leading to insulin resistance over time.
Want to start your day with stable energy instead of a blood sugar crash? Follow me here to learn more about optimization and longevity. -

What is HRV and Why it may be important for your health?
Heart Rate Variability (HRV) refers to the variation in the time interval between consecutive heartbeats. It is a key measure of the autonomic nervous system’s regulation of the heart, reflecting the balance between the sympathetic (fight or flight) and parasympathetic (rest and digest) nervous systems.
HRV is typically measured using an electrocardiogram (ECG) or wearable devices that track heart rhythms. It is usually expressed in milliseconds (ms). A high HRV indicates a healthy and adaptable autonomic nervous system, meaning the body can efficiently manage stress and recover well. On the other hand, a low HRV may suggest stress, fatigue, or underlying health issues, indicating less flexibility in heart rate adjustments in response to activity or environmental changes.
HRV plays a significant role in monitoring stress and recovery. A higher HRV is often associated with better recovery and lower stress levels. It is also widely used in physical fitness, as athletes rely on HRV data to tailor their training intensity, helping to prevent overtraining and optimize performance. Additionally, HRV is used in medical settings to monitor conditions such as cardiovascular disease, diabetes, and mental health issues like anxiety and depression.
Heart rate variability is a feature available on many smart monitors, including watches and fitness devices. Since HRV reflects the effects of stress hormones, it provides insights that differ from an individual’s actual heart rate. For example, after a night of poor sleep and crossing multiple time zones on a trip to England, my HRV dropped from my usual 34ms. While not a drastic change, I expect it to return to normal over the next few days. Monitoring HRV is one of the key metrics I track regularly, alongside my Sleep Score.
For those looking to improve their metabolic health, using a smart device is highly recommended. Fitbit is among the best fitness trackers, while Apple and Samsung watches offer similar features. More specialized devices like Whoop operate on a subscription model, and for those who prefer to keep their wrists free, the Oura Ring is a tracking ring with long battery life, making it ideal for overnight monitoring—though it comes at a higher price point. If you need help selecting or interpreting HRV data, feel free to reach out.
Improving HRV involves activating the parasympathetic nervous system, which is primarily mediated through the vagus nerve. Since this system is the opposite of the sympathetic (fight-or-flight) response, activities that enhance HRV are related to feelings of safety and relaxation. These include better and sustained sleep with adequate deep sleep periods, meditation or mindfulness practices that promote relaxation and stress reduction, controlled breathing exercises that enhance vagal tone, and social connectivity through meaningful interactions and relationships.
We will explore each of these strategies in detail in a future discussion. While these factors may be harder to define in the context of healthier living, they are no less important. Stay tuned for more insights on HRV and overall well-being!
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Move More, Live Longer: Why Small Steps Make a Big Difference in Longevity
When it comes to health and longevity, all movement matters. I’m a big believer in testing—after all, “what gets measured gets noticed.” But too often, aches and pains send us straight to medical imaging, leading to a cascade of diagnoses that may not actually explain the discomfort. A physiotherapist once introduced me to the term VOMIT—Victim Of Medical Imaging and Technology. Intrigued, I asked what she meant.
With the widespread availability of CT scans, MRIs, and other imaging tools, we’re quick to “find” something—tears, frayed ligaments, cartilage loss. And just like that, we assume the issue is purely mechanical, when in reality, many cases of joint and tendon pain stem from poor overall health and lack of movement, not structural damage. This leads to an endless cycle of treatments, medications, injections, and even surgery.
The human body is an interconnected system—few issues exist in isolation. Osteoarthritis, for example, is more common in people with metabolic diseases like fatty liver and diabetes. Pain is often a symptom of a sedentary lifestyle. Like any machine, the body rusts and seizes up when it stays still for too long.
So, the solution? Move more. Physical activity is a powerful tool against multiple health conditions. Yet many avoid exercise because they believe it requires extreme effort—sweat, pain, exhaustion, and dragging themselves to the gym. It doesn’t have to be that hard. One of the simplest and most effective forms of movement is walking. If exercise came in pill form, we’d all be taking it.
I often recommend walking two to three times a day for 20 to 30 minutes. Even modest activity—6,000 to 8,000 steps per day—can reduce the risk of heart disease, dementia, and type 2 diabetes by 15 to 30%. Walking can also kickstart a positive feedback loop—as you move more, you feel better, and small improvements snowball into larger health gains. In contrast, inactivity often leads to a downward spiral—pain leads to less movement, which causes weight gain, muscle loss, and further health decline.
Aging-related fitness decline happens gradually, making it hard to notice. Ask yourself: Do you get out of breath climbing stairs? Can you do 20 chair squats in 30 seconds? Can you complete 20 pushups? The effects of aging begin in our 40s, even if they’re not obvious until later. Fitness is like a retirement account—the more muscle mass and cardiovascular capacity you build now, the more reserves you have for later.
Despite all the hype around biohacking—cold plunges, sauna, supplements, delaying coffee—the biggest impact still comes from fundamental habits: moving daily, prioritizing sleep, eating home-cooked meals, maintaining healthy blood pressure and cholesterol levels (ideally without medication), limiting alcohol, staying socially connected, and finding a sense of purpose.
No pill, supplement, or high-tech procedure can replace the benefits of movement. And the easiest way to start? Go for a walk.
