A Muslim's Lifelong Marathon

The following is for educational purposes only and does not constitute medical advice. Please refer to your healthcare provider before undertaking any new activity.

The Lifelong Marathon

The marvel of the human heart is truly remarkable. This fist-sized muscle pumps approximately 2,000 gallons (7,600 litres) of blood daily through an expansive network of blood vessels stretching over 60,000 miles (100,000 kilometres).[1] It operates with a highly sophisticated electrical system, equipped with numerous fail-safes, and exhibits a level of resistance to corrosion and wear that surpasses any human-made engineering feat. [2] The blood vessels themselves represent a triumph in materials science, boasting strength, durability, flexibility, and permeability, along with an extraordinary capacity for regeneration. [3] However, despite their incredible design and resilience, these wonders of biological engineering are not immune to damage caused by our lifestyle choices.[4] Fortunately, just as regular maintenance can extend a car's lifespan, there are actionable steps we can take to nurture and preserve the health of our heart, ensuring it functions optimally for a lifetime.

The teachings of the Quran and the Sunnah remind us that our bodies are a trust from Allah (SWT), and maintaining our health is a form of stewardship that reverberates through our spiritual and physical well-being.

The Miracle of the Heart

The miracle of the cardiovascular system cannot be overstated. Allah SWT states in the Holy Quran:

ثُمَّ خَلَقْنَا ٱلنُّطْفَةَ عَلَقَةًۭ فَخَلَقْنَا ٱلْعَلَقَةَ مُضْغَةًۭ فَخَلَقْنَا ٱلْمُضْغَةَ عِظَـٰمًۭا فَكَسَوْنَا ٱلْعِظَـٰمَ لَحْمًۭا ثُمَّ أَنشَأْنَـٰهُ خَلْقًا ءَاخَرَ ۚ فَتَبَارَكَ ٱللَّهُ أَحْسَنُ ٱلْخَـٰلِقِينَ ١٤

“Then We made that zygote a clinging mass. Then, We developed that clinging mass into a lump of flesh (chewed with teeth). Then, out of this chewed lump, We developed a structure of bones and clothed the bones with flesh (and muscle). Later, We developed it (gradually) into a new form. So blessed is Allah, the Best of creators.”[5]

Our bodies so elegantly weaved together, have inbuilt physiologic machinery that governs everything from how our DNA is expressed to our heart’s response to stress. The Prophet Muhammad (ﷺ) said: “Each one of you is constituted in the womb of the mother for forty days, and then he becomes a clot of thick blood for a similar period, and then a piece of flesh for a similar period. Then God sends an angel who is ordered to write four things...his deeds, his livelihood, the date of his death, and whether he will be blessed or wretched. Then the soul is breathed into him…”[6]

The heart begins beating spontaneously around the 6th week of gestation (right around 40 days).[7] From this point, it spends an entire lifetime tirelessly providing the body with oxygen and nutrient-rich blood.

The Prophet Muhammad (ﷺ) stated: “Beware! There is a piece of flesh in the body - if it becomes good (reformed), the whole body becomes good, but if it gets spoiled, the whole body gets spoiled, and that is the heart.”[8] It is evident that the state of the entire body reflects the state of the heart. It is also evident in hadith that our marvellous hearts do, in fact, need regular maintenance.

Prophet Muhammad (ﷺ) also stated: “These hearts - just like iron - become rusted, and the way to remove this (the way to clean the rust from the hearts) is through the recitation of the Qur’an.” (Bukhari). While the Prophet (ﷺ) so eloquently describes spiritual care for the heart, he was also noted to be in excellent physical shape, demonstrating wrestling prowess and would race with his wife Aisha.[9] In another narration, Umar wrote to AbuʼUbaidah bin al-Jarrah [saying]: “Teach your children swimming.”[10]

The miracle of the heart was made clear over 1400 years ago. While we are still grappling with fully understanding it to this day, we do have a good idea of how this cardiovascular system can age and fail.

The Natural Course of Aging

By far, the most common cause of death in the developed world is cardiovascular disease.[11] Heart attacks, heart failure, and strokes cause significant disability and quickly erode the quality of life for millions of people around the world.

Atherosclerosis, a gradual and complex process, leads to the stiffening and narrowing of arteries over decades, beginning as early as childhood.10 This silent progression stems from the accumulation of fatty deposits, cholesterol, and other substances on the arterial walls. The initial trigger is often damage to the endothelium, the artery's inner lining, caused by oxidative stress, high blood pressure, elevated cholesterol, smoking, and diabetes.[12] This damage prompts an inflammatory response, attracting white blood cells that transform into foam cells, contributing to plaque buildup.

As plaques grow, they harden and constrict the arteries, limiting blood flow. Some plaques may rupture, creating blood clots that can block arteries, causing heart attacks and strokes. The severity and pace of atherosclerosis varies by genetics, daily food choices, and exercise habits.[13]

Decades of unchecked progression result in compromised arterial health, leading to cardiovascular diseases such as coronary artery disease, leading to heart attacks; cerebrovascular disease, leading to strokes; and peripheral artery disease, reducing mobility and stamina. These conditions significantly diminish quality of life and can severely limit physical activity.

Our body operates on a fine balance between "fight or flight" and "rest and digest" modes, governed by our sympathetic and parasympathetic nervous systems, respectively.1 However, as we age, our heart's ability to respond to these systems begins to diminish.[14] The signals to speed up our heart rate during activities like exercise (sympathetic stimulation) or to slow it down during rest (parasympathetic stimulation) become less effective.[15] This leads to a decreased ability of the heart to adjust its function based on our needs, impacting daily activities and our capacity to handle stress. Consequently, our maximum heart output and VO2 max, which measures the body’s efficiency in utilizing oxygen, also decline.[16] This reduction in aerobic capacity can make tasks as simple as walking up a hill or getting out of bed increasingly challenging and is a predictable part of the ageing process.[17]

As we age, our cardiovascular system undergoes significant molecular and cellular changes, with mitochondria playing a central role in this process. Mitochondria, the powerhouse of cells, are responsible for producing energy and regulating cellular metabolism. In the aging heart and vascular system, mitochondria experience a decline in function, characterized by reduced efficiency in energy production and an increase in the production of reactive oxygen species (ROS).[18] This oxidative stress damages cellular components, leading to arterial damage to the inside layer, or endothelium, which is a critical factor in cardiovascular diseases.[19] Aging mitochondria show decreased rates of biogenesis (creation of new mitochondria) and mitophagy (removal of damaged mitochondria), leaving us with an accumulation of dysfunctional mitochondria. These mitochondrial changes not only diminish the heart's energy supply but also worsen the process of atherosclerosis by promoting inflammation and damage. This vicious cycle accelerates the ageing process on a cellular level.

Aerobic Exercise: We are Created to Move

لَقَدْ خَلَقْنَا ٱلْإِنسَـٰنَ فِى كَبَدٍ ٤

–Indeed, We have created humankind in ˹constant' struggle.[20]

The good news is that we are able to not only slow down but even reverse some of the changes in ageing we've discussed. Allah (SWT) has gifted each of us with the physiological machinery to do this ourselves. Regular doses of exercise are the best-known medicine we have for reducing all causes of mortality, even at as little as 3 hours a week.[21]

Weight Loss: Of course, regular aerobic exercise will increase your caloric expenditure and can lead to obtaining and more easily maintaining a healthy weight. This, in and of itself, provides enormous health benefits and is a motivator for many people. Weight loss is the tip of the iceberg, however, there are so many more benefits to unpack.

Mitochondrial Vitality: Aerobic exercise stimulates the production of new mitochondria and boosts the efficiency of existing ones, combating the decline in energy production that comes with age.[22] Specifically, exercise wakes up the genetic machinery that keeps cells and their mitochondria young and fresh, doing the same for you as a whole.

Antioxidant Factory: Regular bouts of aerobic exercise up-regulate the production of antioxidant genes. While bouts of exhaustive exercise cause a degree of oxidative stress in and of itself, it is precisely what sends a powerful signal to the body’s genes, causing it to produce more antioxidants long term. In fact, it was even discovered (in mice) that taking antioxidants around training interferes with that powerful signal and hampers the beneficial adaptations.[23]

Atherosclerosis Prevention: The buildup of plaques in our arteries accelerates with age, but exercise acts as a natural artery cleaner and can regress already existing fatty deposits.[24] Regular exercise increases the amount of circulating HDL, better known as ‘good’ cholesterol, reducing the risk of heart attacks and strokes. Exercise also signals the body to create more blood vessels to the heart and body, making it more resilient to the effects of blockages in the future.

Cardiac Output and VO2 Max: As we age, our heart's ability to pump efficiently declines, but aerobic exercise can fortify the heart muscles, enhancing blood flow and increasing the heart's pumping capacity. This not only helps to offset the natural decrease in cardiac output associated with ageing but can also improve the heart's ability to respond to stress and physical activity.[^24]

In essence, exercise offers a holistic approach to ageing, touching upon nearly every aspect of physiological decline with the promise of not just halting but reversing many ageing markers. Movement is medicine and is the cornerstone for a successful strategy to maintain vitality and health well into our later years. This prescription doesn't come in a pill bottle but through a commitment to a lifestyle where physical activity is prioritized.

The key to a beneficial exercise regimen is consistency and enjoyment. By choosing activities that you look forward to and can practice regularly, you set the foundation for a lifetime of health benefits. Remember, the key is not just to 'exercise' but to weave physical activity into the fabric of your daily life, reaping rewards that extend far beyond weight loss, including a more resilient body, a sharper mind, and a happy and balanced life.

The teachings of the Quran and the Sunnah remind us that our bodies are a trust from Allah (SWT), and maintaining our health is a form of stewardship that reverberates through our spiritual and physical well-being. By embracing aerobic exercise as a lifestyle, we unlock benefits that extend far beyond weight loss, cultivating a body that is not only stronger and more resilient but fundamentally rejuvenated.

Let this serve as a reminder, guiding us toward a lifestyle that cherishes and prioritizes the miraculous gift of health, ensuring that we can embark on life's adventures with vigour and vitality.