Keeping Your Heart Healthy with Dr Boon Lim

Dr Boon Lim, Consultant Cardiologist at OneWelbeck Heart Health, has released a book as part of the Penguin Life Experts series. In this concise guide, Dr Lim shares his advice for achieving optimum heart health, from hypertension, cholesterol and inherited cardiac conditions, to chest pain, fainting and stress. Read an exclusive extract from the book below, and scroll to the bottom to purchase.


Over the millennia of human evolution, the stress response has kept generation after generation of people alive. Surging heart and breathing rates, eye-pupil dilation and increased blood flow to the muscles prepared our ancestors to successfully fight predators, prey, rivals and other threats – or to flee the scene to safety, when necessary. And after our ancestors managed to slaughter some ferocious sabre-toothed tiger or massive woolly mammoth and bring it home for a feast, they would sleep for many hours, perhaps even days. Under the thrall of the parasympathetic nervous system, their bodies enjoyed long stretches of rest, relaxation and rejuvenation between sudden but temporary bursts of adrenaline and cortisol.

Fast-forward to modern life – a period for which our automatic stress responses are less ideally evolved. Most of us now feel under continuous threat from things that are not so easy to escape. If a snake appears near where you’re sitting, you run away or kill it, but once you’ve removed the threat, your heart and breathing rate quickly settle back down to normal. Getting pinged from the moment you wake until late in the evening by emails from your boss, becoming anxious about making your mortgage payments or paying your monthly bills, worrying about how you’ll be able to care for your children or ageing parents, thinking about your own health, especially in keeping your heart healthy a world reshaped by the first global pandemic in a century these are stressors that can’t be dispatched by running away or grabbing a rock. In other words, modern-day living has replaced intermittent, short-lived bursts of healthy stressors with ever-present chronic stress. Chronic stress puts us in a constant state of sympathetic nervous-system activation, which in turn prevents the parasympathetic nervous system from expressing itself as often or as completely as our body wants or needs to ensure that our cells and tissues are resting and rejuvenating adequately. Much more time in fight-or-flight mode and much less time in rest-and-digest mode may be why people over the past century have been experiencing higher rates of premature heart disease, high blood pressure, palpitations, digestion troubles such as irritable bowel syndrome, sleep disorders like insomnia and mental-health conditions like anxiety and depression.

Thankfully, there are ways in which we can give our parasympathetic nervous system a boost, quieting our sympathetic activation.

The ancient art of breathing

Most of the time you breathe in and out without much thought. You may notice your rate of breathing increasing, and may even feel short of breath, when you exert yourself, like when you do a set of reps in your high-intensity interval (HIIT) training. Your rate of breathing also increases if you’re frightened or stressed. When you’re resting and digesting, your breathing slows down. It is now increasingly understood from a scientific perspective that our breathing regulates the balance between the body’s fight-or-flight reflex and its rest-and-digest mode. Changing how you breathe sends bottom-up (body-to-brain) feedback to the autonomic nervous system, shifting it from fight-or-flight towards rest-and-digest. It’s also easier to get into and maintain a state of emotional self-regulation and calm – what I call your ‘heartset’. Finding this heartset through slow, mindful breathing sets off a cascade of other changes in your body, including the release of beneficial hormones that have restorative effects throughout the body.

  1. Feel your pulse for thirty seconds, giving it your fullest concentration. This means no emails, no talking, no texting, no watching TV or YouTube. It may help your focus to close your eyes.
  2. Carefully notice the regularity of your pulse. Don’t bother to count your pulse rate. Pay attention instead to how you’re able to change your pulse rate.
  3. After thirty seconds, take a deep breath from your belly to fully expand your lungs. Then let all the air out, slowly.
  4. Next, slow down your breathing rate. Breathe in slowly for five seconds, then breathe out for five seconds. If you cannot manage five seconds, try three seconds, gradually increasing the time you take on each breath.
  5. Return your attention to the regularity of your pulse. Notice the subtle changes in your heart rate with each rise and fall of your breath.
  6. Bonus step 1: Start to imagine the following: I am self- regulating my body through my breathing, and I am allowing the power of these breaths to infuse my a better balance between stress and rest keeping your heart healthy heart, body and mind with optimal health. It may be easier to hear these words, or words like them, in your mind or by speaking them aloud.
  7. Bonus step 2: Your breathing won’t just slow your pulse; it will also lower your blood pressure. You can see this if you have a home blood-​pressure monitor. Take your blood-​pressure reading once, then breathe at a steady pace for three minutes, then take another reading. Your monitor will show consistently lower readings after slowing down your pulse.

Establishing a better psychological and emotional balance in life is vital to physical health and well-being. Making the change now, starting with just three minutes of breathing, will improve your heart and your health, immediately.

Five top tips for creating a better balance between stress and rest

  1. Create a daily routine: Routines are powerful tools for improvement, as they enable you to create a habit out of stress reduction. You can set a routine including any number of intentions: for example, to do your wake-up gratitude, breathing and goal-setting exercises; to leave for a destination ten minutes earlier than you need, so that you can walk an extra block or stop on your way; to remove all mobile devices from the dining table during a family meal; to turn off your work devices at a set time in the day to enable you to focus on your family, your personal hobbies, your health and yourself; or to wind down one hour before bedtime – no exceptions.
  2. Slow your breath: Spend time breathing slowly more often during the day. Breathe in this way when you wake up, when you notice you’re getting stressed or emotional, when you’re getting ready for bed and whenever you find you’ve got a free minute or two. You may also find longer breathing meditations, like the ones in yoga or mindfulness meditation, to be helpful.
  3. Observe more: Spend time paying more attention to the present moment – the wind on your skin, the colour of the sky, the sense of sitting grounded in your chair, the emotions that rush over you when you think of a cherished loved one (or a deadline), the rate of your breathing and heartbeat. Mindfulness exercises are designed to help train your mind to focus more on the present versus the past and the future, reducing the impact of chronic stress. But it’s also good for your a better balance between stress and rest keeping your heart healthy health (and lowers stress levels) to observe what you have to be grateful for – and to relish those positive feelings every day.
  4. Exercise more: Being physically active is a great stress- reliever. It helps by putting the adrenaline released by the sympathetic nervous system to work for the purpose that nature intended – moving your limbs and getting your heart pumping, with a short burst of healthy physical activity. HIIT workouts are great for this, training your body to quickly shift out of fight-or-flight mode – something that also happens when you cap your workout with a shower in the Wim Hof way, with a shock of cold water.
  5. Get a good night’s sleep. There are so many ways in which sleep, stress and immune function are interrelated that it’s essential to make seven to nine hours’ sleep a night a goal for everybody.

How to buy

The above extract was taken from Keeping Your Heart Healthy, written by Dr Boon Lim, Consultant Cardiologist at OneWelbeck Heart Health. You can purchase the book on Amazon. Click here to be taken through to

How OneWelbeck can help

Here at OneWelbeck, we have a team of cardiology specialists, state of the art facilities and diagnostics, and highly competitive financial packages for self-funding patients as well as those with private health care.

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