Tag: longevity

  • Personalising Coffee Intake for Optimal Health: Lessons from the CRAVE Trial

    Personalising Coffee Intake for Optimal Health: Lessons from the CRAVE Trial

    Coffee is one of the most popular beverages consumed globally and is certainly the most popular beverage at Coyne Medical. Its health effects have been the subject of numerous observational studies. However, the majority of these studies are prone to confounding by other factors, and there is a lack of randomised controlled trials examining the acute (short-term) effects of coffee consumption. The Coffee and Real-time Atrial and Ventricular Ectopy (CRAVE) trial was designed to address this gap in knowledge.

    The CRAVE trial involved 100 adults fitted with wearable monitors, including an electrocardiogram-recording device, an accelerometer, and a continuous glucose monitor. Participants were randomised via daily text messages to either consume all the caffeinated coffee they wanted or avoid all caffeine. Adherence to the randomisation assignment was assessed using various methods, including a real-time participant activation button on the ECG monitor to timestamp every cup of coffee.

    The primary outcome of the study was premature atrial contractions (PACs), which are a potent harbinger of atrial fibrillation risk. PACs are premature heartbeats that arise from the atria, the upper chambers of the heart. Atrial fibrillation is an important risk factor for stroke. The study found that consumption of caffeinated coffee was not associated with an increased frequency of PACs. However, days randomised to coffee were associated with 51% more premature ventricular contractions (PVCs), which are associated with an increased risk of subsequent heart failure in older adults. PVCs are premature beats that arise from the lower chambers of the heart. Those who consumed more than two cups of coffee experienced more than a doubling of their PVCs. 

    The study also found that on days randomised to coffee, participants took about 1000 more steps but experienced more than a half-hour less sleep. Despite epidemiological evidence that coffee consumers experience a lower risk of developing diabetes, no differences in serum glucose were observed in any of the analyses comparing exposure to coffee with caffeine avoidance.

    The study revealed complex acute effects of coffee related to several physiological processes fundamental to overall health, which manifest differently between individuals. The findings suggest that those concerned about PVC frequency and the associated risk of subsequent heart failure might consider reducing or eliminating coffee. These would be people who are known to have these types of abnormal heartbeats and are usually, over 65 years of age. However, those struggling with insomnia should incorporate this study data to motivate at least a trial of strict coffee avoidance to determine if it might benefit their sleep.

    The CRAVE trial provides valuable insights into the acute effects of coffee consumption and highlights the importance of personalised lifestyle goals. The multidimensional effects of caffeinated coffee consumption should be taken into consideration when making decisions about coffee consumption, and individuals should consider their own health concerns when determining their coffee intake. Taken overall, the study provides important information that can be used to facilitate improved shared decision-making and promote longevity and healthspan.

    DR J HUGH COYNE
    MBBS BSc PGDip (with merit) MRCGP DRCOG DCH

    Dr Hugh Coyne is a GP and co-founder of Coyne Medical, a private preventive health clinic at 660 Fulham Road, London. He trained at Imperial College London and has been in practice for over twenty years, with a particular focus on cardiovascular risk, metabolic health, and exercise medicine. After qualifying as a GP he went on to train in sport and exercise medicine, bringing a distinctly practical approach to prevention and long-term health.

    British Association of Sports and Exercise Medicine  ·  European Atherosclerosis Society  · 
    Independent Doctors Federation

    As seen in The Independent, The Daily Mail and Tatler

    Book a Health Screening

    For educational purposes. This article is written by a practising GP and is intended to inform, not replace a consultation with your own doctor. It does not constitute medical advice. A note on clinical guidelines: Coyne Medical is an independent private clinic. Our approach is guided by the best available evidence, tailored to each individual. This may go beyond standard NHS or NICE guidance, which is designed for population-level care and weighted by resource constraints.

    Read More Nutrition & Lifestyle Guides
  • The Link Between Alcohol Intake and Longevity: Insights from a Systematic Review and Meta-Analysis

    The Link Between Alcohol Intake and Longevity: Insights from a Systematic Review and Meta-Analysis

    Alcohol consumption has been a controversial topic in the health and wellness community for years. While some studies have suggested that moderate alcohol consumption can have health benefits, others have found a strong association between alcohol consumption and all-cause mortality. A recent systematic review and meta-analysis of 107 cohort studies conducted between 1980 and 2021 sheds new light on this topic and provides valuable insights into the association between alcohol intake and mortality, particularly in relation to longevity and healthspan.

    The history of human alcohol consumption dates back far longer than controversy regarding its effect on longevity. Indeed, alcohol was sometimes the only safe liquid to drink when clean drinking water was a rarity. Alcohol consumption can be dated to the Neolithic period, around 10,000 BCE. Archaeological evidence suggests that humans in the Middle East and China were fermenting beverages from ingredients like grapes, rice, and honey during this time. The earliest evidence of a specific alcoholic beverage is a 9,000-year-old Chinese fermented beverage made from rice, honey, and fruit. Other ancient fermented beverages include mead made from honey and wine made from grapes. The consumption of alcoholic beverages has been an important part of human culture for thousands of years.

    Sumeria, located in modern-day Iraq, was one of the earliest civilisations in the world, and its people were known for their advancements in agriculture, metallurgy, and writing.

    Sumerians were skilled brewers and consumed beer on a daily basis. They brewed their beer from barley, which was a staple crop in the region. The beer was made by baking barley bread, crumbling it, and then soaking it in water. The mixture was then left to ferment, with the natural yeast present in the air causing the liquid to turn into beer.

    Beer was an important part of Sumerian culture, and it was consumed during religious ceremonies, as well as in everyday life. The Sumerians even had a goddess of beer, named Ninkasi, who was worshipped for her ability to provide them with the drink.

    Alcohol consumption has been around for thousands of years. I have always thought it odd that something that has endured for so long could be dangerous in moderation. The objective of this recent study was to investigate the association between alcohol use and all-cause mortality. It also had another objective. To find out how sources of bias may change results. Sources of bias include, “former drinker bias” where previous drinkers are lumped together with lifelong abstainers. The data sources were a systematic search of PubMed and Web of Science, which identified studies published between January 1980 and July 2021. Cohort studies were identified by systematic review to facilitate comparisons of studies with and without some degree of controls for biases affecting distinctions between abstainers and drinkers.

    The study identified 107 studies of alcohol use and all-cause mortality published from 1980 to July 2021, with 4,838,825 participants and 425,564 deaths available for analysis. Mixed linear regression models were used to model relative risks, first pooled for all studies and then stratified by cohort median age (<56 vs ≥56 years) and sex (male vs female). The data were analyzed from September 2021 to August 2022.

    The study found that higher amounts of alcohol consumption were associated with an increased risk of all-cause mortality. This finding was statistically significant, indicating that excessive alcohol consumption can have serious health consequences. The study also revealed that there was a reduction in the all-cause mortality rate among occasional drinkers compared with nondrinkers, but this finding was not statistically significant. This finding confirms a J-shaped risk. That is, there is a protective association at low amounts of alcohol and increasing risk at higher amounts. Interestingly, J-shaped curves appear a lot in longevity. Particularly in relation to exercise and longevity. 

    The results of the study were then further analysed based on sex, and it was found that females had an increased risk of all-cause mortality at lower levels of alcohol consumption. This is an important finding as it highlights the need to consider sex-specific recommendations for alcohol consumption to promote longevity and healthspan.

    The study also compared its results with those of previous meta-analyses and found that the risk estimates may have been affected by the number and quality of studies available at the time, especially those for women and younger cohorts. This highlights how important it is to continue to conduct high-quality studies on the association between alcohol use and mortality to better understand its effects on longevity and healthspan.

    This updated systematic review and meta-analysis provides the best current evidence that daily low or moderate alcohol intake is not significantly associated with all-cause mortality risk, while the increased risk is evident at higher consumption levels, starting at lower levels for women than men. The study suggests that drinking more than 25 g, or 3 UK units, of alcohol per day or more is associated with an increased risk of mortality. 3 units are just over a pint of 4% beer or a small glass of wine. This is a critical finding for improving longevity and healthspan given that excessive alcohol consumption can lead to numerous health problems, including liver disease, cancer, and cardiovascular disease. In the context of human history, the study findings make sense when it is considered that for most of human history beer had a low alcohol content. 

    DR J HUGH COYNE
    MBBS BSc PGDip (with merit) MRCGP DRCOG DCH

    Dr Hugh Coyne is a GP and co-founder of Coyne Medical, a private preventive health clinic at 660 Fulham Road, London. He trained at Imperial College London and has been in practice for over twenty years, with a particular focus on cardiovascular risk, metabolic health, and exercise medicine. After qualifying as a GP he went on to train in sport and exercise medicine, bringing a distinctly practical approach to prevention and long-term health.

    British Association of Sports and Exercise Medicine  ·  European Atherosclerosis Society  · 
    Independent Doctors Federation

    As seen in The Independent, The Daily Mail and Tatler

    Book a Health Screening

    For educational purposes. This article is written by a practising GP and is intended to inform, not replace a consultation with your own doctor. It does not constitute medical advice. A note on clinical guidelines: Coyne Medical is an independent private clinic. Our approach is guided by the best available evidence, tailored to each individual. This may go beyond standard NHS or NICE guidance, which is designed for population-level care and weighted by resource constraints.

    Read More Nutrition & Lifestyle Guides
  • Small Dietary Changes, Big Health Benefits: Lowering Cancer Risk with Non-Processed Foods

    Small Dietary Changes, Big Health Benefits: Lowering Cancer Risk with Non-Processed Foods

    Are you concerned about your cancer risk? A new study from the European Prospective Investigation into Cancer and Nutrition (EPIC) suggests that making a small change to your diet may significantly reduce your risk of cancer and thus improve longevity.

    The study found that when 10% of ultra-processed foods were replaced with non-processed foods, the overall risk of cancer and of specific cancers, such as colon and postmenopausal breast cancers, decreased. Crucially, these results held true even when adjusted for other risk factors for cancer such as BMI, alcohol and dietary intake, and food quality.

    So what are ultra-processed foods? They include foods like processed meats, fizzy drinks, packaged snacks, and ready meals. These foods typically contain eye-wateringly high levels of added sugar, salt, and fat, along with artificial colours, flavours, and preservatives. Unfortunately, these food have also been designed to taste great. 

    The study’s findings suggest that the processing of food may play a role in cancer development. By replacing just a small portion of ultra-processed foods with non-processed options, you may be able to reduce your cancer risk.

    Non-processed foods, by contrast, are foods that are minimally processed and remain close to their natural state. Examples, of course, include fruits, vegetables, whole grains, nuts, and seeds.

    The EPIC study is a large-scale epidemiological study that has investigated the association between dietary intake and cancer risk. The study recruited over 500,000 participants from 23 centres across 10 European countries between 1991 and 2001. Participants completed dietary questionnaires and were followed up for an average of 15 years. The study used the NOVA food processing classification system to categorise foods based on their level of processing. This system categorises foods into four groups: unprocessed or minimally processed foods, processed culinary ingredients, processed foods, and ultra-processed foods.

    The study found that a 10% increase in the proportion of ultra-processed foods in the diet was associated with a 12% increase in overall cancer risk. In contrast, a 10% increase in the proportion of unprocessed or minimally processed foods was associated with a 10% decrease in overall cancer risk. The study also found that a higher intake of ultra-processed foods was associated with an increased risk of specific types of cancer, including breast, colorectal, and throat cancer.

    Overall, the study provides strong evidence that reducing the intake of ultra-processed foods and increasing the intake of unprocessed or minimally processed foods may lower the risk of developing cancer. It’s important to note that this study was a prospective cohort substitution study, meaning that it didn’t directly measure the effects of diet on cancer risk. Rather, it analysed the effects of substituting certain foods in the diet with other foods.

    Despite this limitation, the study’s findings remain compelling. If you’re looking to reduce your cancer risk, consider making small changes to your diet. Replace processed snacks with fresh fruits or veggies or nuts, swap sugary drinks for water (I drink a lot of naturally flavoured sparkling water) or unsweetened tea, and choose whole grains over refined grains. By making these simple changes, you may be able to reduce your cancer risk and improve your overall healthspan.

    DR J HUGH COYNE
    MBBS BSc PGDip (with merit) MRCGP DRCOG DCH

    Dr Hugh Coyne is a GP and co-founder of Coyne Medical, a private preventive health clinic at 660 Fulham Road, London. He trained at Imperial College London and has been in practice for over twenty years, with a particular focus on cardiovascular risk, metabolic health, and exercise medicine. After qualifying as a GP he went on to train in sport and exercise medicine, bringing a distinctly practical approach to prevention and long-term health.

    British Association of Sports and Exercise Medicine  ·  European Atherosclerosis Society  · 
    Independent Doctors Federation

    As seen in The Independent, The Daily Mail and Tatler

    Book a Health Screening

    For educational purposes. This article is written by a practising GP and is intended to inform, not replace a consultation with your own doctor. It does not constitute medical advice. A note on clinical guidelines: Coyne Medical is an independent private clinic. Our approach is guided by the best available evidence, tailored to each individual. This may go beyond standard NHS or NICE guidance, which is designed for population-level care and weighted by resource constraints.

    Read More Nutrition & Lifestyle Guides
  • Squatting For Beginners

    Squatting For Beginners

    Squatting is Good For You!

    Fundamental movements are movements that are essential for maintaining independent living and enjoying exercise. They include movements such as squatting, lunging, running and hanging. Learning the correct technique to perform fundamental movements is known to reduce the risk of injury in children. It is not only children who benefit from proficiency in these movements. To maintain balance, and thus independence, and to avoid injury, older adults must maintain their ability to perform fundamental movements. 

    Squatting is a particularly important exercise. It is not only foundational to sporting activity but it is also crucial to everyday tasks such as sitting and lifting. Getting up from a sitting is a fundamental task for living independently into old age. The longer we can perform a squat, the longer we will remain independent in old age. 

    Squatting activates the largest muscles in our bodies. The quads, glutes, hamstrings, and calf muscles are all activated during a squat. These large muscles are important not only for movement and balance but also for our metabolism. Muscles act as a store of glucose. They are therefore crucial to how our bodies handle sugar. 

    A squat, when performed correctly, does not compromise the structural integrity of the knees. In fact, it can enhance our stability. This is crucial, as maintaining balance and stability becomes increasingly important as we age. Falling in old age can have disastrous consequences. In addition, squatting, when performed correctly, can improve the stability of the knee and reduce the risk of sports injuries. Being able to squat correctly is a prerequisite to being able to perform more ballistic, explosive movements such as box jumps and plyometrics. The squat mimics the explosive movements required in many sports. Thus, improved squatting enhances sporting performance. 

    Due to its importance in everyday life and because it activates the largest muscles in the body, squatting is fundamental to any resistance training program. Squatting also acts as a useful tool in the doctor’s, physiotherapist’s, or osteopath’s office to screen for any issues with movement mechanics. This is because the squat is what is known as a “compound manoeuvre.” Compound exercises are loved by physical trainers because they require the use of several muscle groups working in collaboration. These exercises are incredibly useful for building muscle mass, strength, and power. As it is a compound movement, squatting is incredibly useful for picking out biomechanical problems. These issues can be due to a lack of muscle strength, an imbalance of strength on each side of the body, unstable joints (also due to a lack of strength), and a lack of joint and muscle flexibility. 

    How to perform a squat

    It is highly recommended that you get an experienced personal trainer or physical therapist to observe your squat technique. This can give you the appropriate cues and feedback to ensure rock-solid technique. It can be really helpful to record your squat movements from the front and the side so that you can see any errors that you are making. 

    If you are new to squatting, you can just use your body weight. Ideally, use a dowel or a light (2.5 kg) strength bar. This allows you to begin in the same position that you will progress to when increasing the weight that you are squatting. Using a cylindrical dowel or light weight bar also engages the muscles around the scapula, helping to stabilise the upper body. 

    Bar – Squatting with weights

    Begin in a standing position with your feet flat on the floor. Your knees and hips should be in a neutral position, and your spine should be upright with its natural curves preserved. Grip the bar or dowel with the palms facing forward and slightly wider than shoulder width. The bar should rest just below the neck on the upper back. A good tip when using a bar is to “bend the bar.” This action helps brace the torse and improves squat performance. Keep your wrists straight and your forearms parallel to your torso. 

    Stance 

    Stand with your heels shoulder-width apart and your toes pointing forward or slightly outward by no more than ten degrees.

    Breathing 

    Prior to beginning the downward squat motion, breathe in through your nose and down into your belly to about 80% of a full breath. This increases the pressure in the abdomen and helps prepare and brace the spine for the load. Breathe out through the mouth when you are coming back up. This helps to negate the need for a belt.

    Squat Motion

    The descent phase of the squat begins with “breaking the hips.” The motion is that of sitting down while sticking your bum out. It is almost as though you are trying to sit on a chair that is just too far away. The goal should be to keep your bum as far back from your ankles as you can while maintaining an upright torso. The distance between the hips and shoulders should remain constant. The heels should bear the majority of your body weight. The ideal finishing position is with the thighs just below parallel to the ground. The thighs going past the line parallel to the ground are not more likely to result in injury. The speed of the ascent should be 2-4 times the speed of the descent. 

    The upward motion follows the same path as the downward motion. The glutes, or bum muscles, should be the primary driver of the motion. Again, the low back should be kept stiff, and the shoulder and hips should be at the same distance throughout. The weight should be in the heels (I wear shoes with a very minimalist sole to facilitate this although some people squat without shoes). 

    The main, albeit weird, mental cue I think of when performing a squat is that my buns are cracking a walnut. To cue getting my bum out far enough, I imagine that someone could place a walnut between my bum cheeks when I am at the lowest point of the squat (what a job that would be!). I then imagine that I am crushing that walnut with my bum cheeks in the ascent phase. 

    Avoiding Pitfalls

    The squat is a complex movement. There are several ways it can go wrong and result in injury. Here are a few pointers to help maintain the correct technique. 

    Head Position: The gaze should be aimed forwards, and the neck should be perpendicular to the ground. 

    Chest: The chest should be up and the shoulders should be back. So if you have a logo on your t-shirt, you should be able to see it in the mirror. 

    Trunk/Middle: Your trunk should be in line with your shins at all times. 

    Hips: If you are squatting in the mirror, you should see that your hips should be level and parallel to the ground. 

    Knees: Your knees should travel in line with your second toe and should not tilt inward past the inside of your ankle. 

    Feet: The entire sole of the foot should remain in contact with the ground throughout. 

    Squatting is, I think, the most important resistance exercise. If done correctly, it can improve athletic performance, reduce the risk of injury, maintain independence, and improve metabolism. But it is really important to do it correctly. Start with no weight or a very light weight. Ideally, have an experienced personal trainer or physiotherapist observe your squat motion. 

    DR J HUGH COYNE
    MBBS BSc PGDip (with merit) MRCGP DRCOG DCH

    Dr Hugh Coyne is a GP and co-founder of Coyne Medical, a private preventive health clinic at 660 Fulham Road, London. He trained at Imperial College London and has been in practice for over twenty years, with a particular focus on cardiovascular risk, metabolic health, and exercise medicine. After qualifying as a GP he went on to train in sport and exercise medicine, bringing a distinctly practical approach to prevention and long-term health.

    British Association of Sports and Exercise Medicine  ·  European Atherosclerosis Society  · 
    Independent Doctors Federation

    As seen in The Independent, The Daily Mail and Tatler

    Book a Health Screening

    For educational purposes. This article is written by a practising GP and is intended to inform, not replace a consultation with your own doctor. It does not constitute medical advice. A note on clinical guidelines: Coyne Medical is an independent private clinic. Our approach is guided by the best available evidence, tailored to each individual. This may go beyond standard NHS or NICE guidance, which is designed for population-level care and weighted by resource constraints.

    Read More Nutrition & Lifestyle Guides
  • VO2max Testing

    VO2max Testing

    At Coyne Medical, we are incredibly passionate about the use of exercise as medicine. A huge amount of medical evidence now shows that low levels of fitness are associated with an increased risk of dying from any cause, including heart and vascular disease and cancer rates. In comparison to smoking, having high blood pressure, high cholesterol, or type 2 diabetes mellitus, fitness is a stronger predictor of death. The fitter you are, the lower your chance of dying. The addition of fitness metrics to the standard medical risk variables enables medical professionals to more precisely categorise your disease risk. Being unfit is a massive risk factor for disease. 

    Higher fitness levels are not only associated with a lower risk of death. High fitness is also associated with a lower risk of chronic diseases. The least-fit and next-least-fit groups of people have the most to gain from increased fitness. With increased fitness, these groups have seen a massive reduction in adverse health outcomes. Indeed, bringing VO2 max from the “low” range to merely “below average” reduces mortality by 50%! So there is no need to come anywhere close to the world record of the highest VO2 max of 96.7 ml/kg/min. This highest-ever VO2 max was achieved by Norwegian cyclist Oskar Svendsen. Their cardiovascular risk also declines substantially with increased fitness. Ideally, all adults should have their fitness measured on a regular basis, just like any other preventative check, such as checking blood pressure. The most accurate way to measure your fitness is through a VO2 max test.

    Higher fitness levels are not only associated with a lower risk of death. High fitness is also associated with a lower risk of chronic diseases. The least-fit and next-least-fit groups of people have the most to gain from increased fitness. With increased fitness, these groups have seen a massive reduction in adverse health outcomes. Indeed, bringing VO2 max from the “low” range to merely “below average” reduces mortality by 50%! So there is no need to come anywhere close to the world record of the highest VO2 max of 96.7 ml/kg/min. This highest-ever VO2 max was achieved by Norwegian cyclist Oskar Svendsen. Cardiovascular risk also declines substantially with increased fitness. Ideally, all adults should have their fitness measured on a regular basis, just like any other preventative check, such as checking blood pressure. The most accurate way to measure your fitness is through a VO2 max test. 

    VO2 Max Testing

    VO2 max testing is a form of cardiopulmonary exercise testing (CPET). It is a method used to assess the performance of the heart and lungs at rest and during exercise. VO2 max testing is totally non-invasive. During the test, information about the heart and lungs is collected to understand if the body’s response to exercise is normal. 

    VO2 max, or maximal oxygen consumption, refers to the maximum amount of oxygen that an individual can utilise during intense or maximal exercise. This measurement is generally considered the best indicator of cardiovascular fitness and aerobic endurance. The more oxygen a person can use during high-level exercise, the more energy a person can produce. This test is the gold standard for determining fitness because the muscles need oxygen for prolonged aerobic exercise and the heart must pump adequate amounts of blood through the circulation to meet the demands of the exercise. There is a strong association between VO2 max and longevity. Thus, knowing VO2 max gives us a powerful metric that we know is associated with longevity and that we can objectively improve. That’s right, we can improve our VO2 max. 

    The benefits of VO2 max testing

    Aside from providing the impetus to get fitter in order to live longer, there are several reasons why VO2 max testing is so important:

    • Your current fitness can be accurately measured. This allows doctors to accurately classify your risk of a whole host of diseases. 
    • It allows the capability to create a really efficient, bespoke training programme tailored to you. 
    • It allows the evaluation of the effectiveness of a training programme 
    • It can establish what is optimal running speed or cycling wattage to maximally improve endurance fitness and optimally burn fat
    • It can assist in distinguishing causes of low fitness from cardiac or pulmonary causes
    • From a doctor’s perspective, it can be used to provide helpful prognostic information in those suffering from chronic diseases

    The data obtained from VO2 max testing enables the most precise and standardised quantification of fitness. The primary advantage is the direct measurement of fitness. This is  as opposed to estimating peak or maximal VO2. Establishing exercise intensities (training zones) based on VO2 max testing allows athletes to minimise the risk of injury and fatigue while also enhancing adaptations and responses to the training plan. 

    Older athletes, or those with underlying medical conditions, can also benefit from VO2 max testing. This is because it can provide risk stratification for disease. It also allows safe clearance to participate in sports events. VO2 max can also be used to set training zones and determine exercise limitations for older athletes.

    How VO2 Max is measured

    By putting on a face mask, the volume and gas concentrations of inspired and expired air can be directly measured. This measure is often used in research and is considered the most accurate. The test involves either exercising on a treadmill or a stationary bike. The intensity increases every few minutes until exhaustion. Thus, it is designed to achieve maximal effort. 

    What You Can Learn From VO2 Max Testing

    VO2max testing provided several different metrics that are incredibly useful. 

    • VO2Max
    • This is the maximum amount of oxygen that an individual can utilise during intense or maximal exercise. 
    • As mentioned earlier, there is a strong association between VO2 max and longevity. 
        • It defines the exercise limits of the heart and lungs in healthy people.
        • It decreases with age, 8%-10% per decade in trained individuals who continue to train vigorously. 
        • Men have a VO2 max that is 10%-20% higher than women.
    • Ventilatory Threshold (also known as lactate threshold/ VT1)
        • Anaerobic (without oxygen) metabolism occurs when muscle energy demands exceed oxygen delivery to the muscles.
        • As anaerobic metabolism begins, the breathing rate and breathing effort increase to aid in CO2 removal from the body.
        • At this point, blood lactate levels start to rise, VO2 levels peak, and CO2 production accelerates. Rising lactate levels inhibit performance. So our muscle’s ability to utilise and clear lactate is very important. Training at low intensity helps us clear lactate efficiently. 
        • The measurement sets the upper limit of low-intensity training. 
      • The peak respiratory exchange ratio
        • This is the objective measure of the maximal effort of the participant 
        • It has a huge advantage over estimated maximal heart rate (HRmax), which is often derived from the commonly used equation 220-age
        • When estimated, maximal HR has a large population error of up to 12 bpm and thus is not an ideal indicator of exercise effort
        • Fitness levels have also been shown to influence the decline in maximal HR with age making HRmax even more unreliable. 
    • 2nd Ventilatory threshold (Anaerobic Threshold)
      • At this point. lactate has quickly accumulated in the blood, necessitating heavy breathing to expel CO2.
      • This represents the transition point between moderate and high-intensity exercise.
      • Thus, it sets the limits of high-intensity training

    Implications for Exercise

    Knowing the right intensity to exercise at enables you to maximally improve your fitness performance. Polarised training has been shown to lead to the greatest improvements in endurance performance. This type of training consists of mainly low-intensity, high-volume training (75%).  There is a moderate amount of high-intensity or sprint interval training (20%), and a small amount of training at threshold intensity (5%). Establishing your VT1 and VT2 will help you get the most out of your training. What you can measure, you can manage.  VO2 max is the most accurate way to measure your fitness, and maintaining a high VO2 enhances longevity.

    DR J HUGH COYNE
    MBBS BSc PGDip (with merit) MRCGP DRCOG DCH

    Dr Hugh Coyne is a GP and co-founder of Coyne Medical, a private preventive health clinic at 660 Fulham Road, London. He trained at Imperial College London and has been in practice for over twenty years, with a particular focus on cardiovascular risk, metabolic health, and exercise medicine. After qualifying as a GP he went on to train in sport and exercise medicine, bringing a distinctly practical approach to prevention and long-term health.

    British Association of Sports and Exercise Medicine  ·  European Atherosclerosis Society  · 
    Independent Doctors Federation

    As seen in The Independent, The Daily Mail and Tatler

    Book a Health Screening

    For educational purposes. This article is written by a practising GP and is intended to inform, not replace a consultation with your own doctor. It does not constitute medical advice. A note on clinical guidelines: Coyne Medical is an independent private clinic. Our approach is guided by the best available evidence, tailored to each individual. This may go beyond standard NHS or NICE guidance, which is designed for population-level care and weighted by resource constraints.

    Read More Longevity & Healthspan Guides
  • Could You Have Low Testosterone?

    Could You Have Low Testosterone?

    Low testosterone has been found to occur in almost 40% of men aged over 45. However, it is often overlooked. Often the symptoms that occur due to low testosterone are ascribed to other causes such as depression, anxiety or lack of exercise. 

    Where is Testosterone Produced?

    In men, testosterone is mainly produced by the Leydig cells in the testicles. A smaller amount is produced by the adrenal glands. Usually, testosterone levels are tightly controlled by a feedback system. This feedback loop is regulated by the hypothalamus and the anterior pituitary gland which are located in the brain. 

    Not all men become deficient in testosterone with age. However, as men age testosterone levels do gradually decline. There are a wide range of causes of low testosterone. Therefore, if low testosterone is identified it is important to identify if there is an underlying cause. Yet, in many men, no cause for low testosterone is found. 

    What are the symptoms of low testosterone?

    In adult men, having low testosterone results in a number of potential symptoms and signs including:

    • Mood disorders such as low mood, anxiety, anger and irritability.
    • Decreased sense of wellbeing.
    • Reduced concentration and memory.
    • Changes in body composition such as increased abdominal and visceral fat, increased BMI.
    • Reduced body hair.
    • Muscle wasting and impaired muscle strength.
    • Fatigue and loss of energy.
    • Poor sleep.
    • Thinning and weakening of bones.
    • Increased risk of type 2 diabetes.
    • Hot flushes.
    • Reduced libido.
    • Problems getting or maintaining erections.

    The most common symptoms of low testosterone are low sexual desire, difficulty getting and maintaining erections and reduced morning erections. 

    If you are concerned that you have symptoms of low testosterone, speak to your GP about getting tested. 

    DR LUCY HOOPER
    MB BS BSc MRCGP MA DRCOG DCH

    Lucy is a GP and co-founder of Coyne Medical. She graduated with honours from Imperial College London, trained at St Mary’s Hospital, and holds a Master’s in Medical Ethics and Law. Her clinical interests span women’s health, preventive medicine, and genomics, with a particular focus on using advanced biomarkers to build a more complete picture of long-term health.

    British Society for Genetic Medicine  ·  European Atherosclerosis Society  · 
    Independent Doctors Federation

    As seen in BBC, The Guardian, Women’s Health, The Times and Tatler

    Book a GP Consultation

    For educational purposes. This article is written by a practising GP and is intended to inform, not replace a consultation with your own doctor. It does not constitute medical advice. A note on clinical guidelines: Coyne Medical is an independent private clinic. Our approach is guided by the best available evidence, tailored to each individual. This may go beyond standard NHS or NICE guidance, which is designed for population-level care and weighted by resource constraints.

    Read More Men’s Health Guides