Cycling:
The Drug That
Does Not Come
in a Bottle.
A 44-year study tracked 191 women and found that the fit ones were 88% less likely to develop dementia. Their immune systems were functioning like those of people in their 20s when they were in their 70s and 80s. Their cancer risk was 40 to 54% lower. And they were not professional athletes. They were people who moved consistently on two wheels. This is what the science actually says about cycling.
The Wrong Default framework is not about herbs. It is about returning the body to the state it was always supposed to be in. The Orang Asli did not need cycling articles. They never stopped moving. Movement was not exercise for them — it was simply life. The rest of us drifted from that default and now have to consciously schedule the return.
The herbs are the last layer. Movement is foundational. A body that cycles regularly needs less of everything else: fewer interventions, fewer supplements, fewer prescriptions. The data on this is not marginal. It is among the most robust in all of preventive medicine.
Exercise is the word we invented when we drifted far enough that we had to schedule what we were always supposed to do.
Before the science, before the history — here is what stopped me when I researched this.
- A 44-year Swedish study found that women with high cardiovascular fitness in midlife were 88% less likely to develop dementia than women with medium fitness. If they did develop dementia, onset was delayed by an average of 11 years. The fitness test was performed on a cycling ergometer.
- A study of 125 cyclists aged 55 to 79, published in Aging Cell journal, found they had the T-cell production of adults in their 20s. Their thymus gland — which normally shrinks with age — was the same size as a 20-year-old's. The immune system normally declines 2 to 3% per year from our 20s. Theirs had not declined.
- The UK Biobank study of 263,450 adults found that cycling to work was associated with a 41% lower risk of premature death, a 52% lower risk of dying from heart disease, and a 45% lower risk of developing cancer compared to non-active commuters.
- In Denmark, researchers calculated that the health benefits of cycling are 238 times greater than the mortality risk from cycling accidents. The risk of getting on a bike is not what most people think it is.
- The 10-year Japanese study published in 2025 found that older adults who began or continued cycling were significantly less likely to require long-term care or face premature death — and starting late still counts. It is never too late to begin.
Humans Are Built to Move. The Bicycle Restores That Default.
For the vast majority of human history, sustained rhythmic movement was not optional. It was the condition of survival. Our ancestors walked, ran, climbed, and carried. The bodies we inhabit today were designed across hundreds of thousands of years for precisely this kind of consistent, moderate, sustained physical activity. The cardiovascular system, the lymphatic system, the brain's neuroplasticity mechanisms, the immune system's maintenance processes — all of them function optimally when movement is consistent and regular.
The modern world removed the requirement to move. We sit in cars, at desks, on sofas. The removal happened faster than biology could adapt. And the diseases that followed — the cardiovascular disease, the metabolic syndrome, the cognitive decline, the immune dysfunction — are, in significant part, the biological consequence of a species designed for movement living in a world that removed the requirement for it.
The bicycle is not the solution to an athletic aspiration. It is a practical tool for returning to a biological default that the modern world removed. This is why the data on cycling and health is so consistent, so large in effect size, and so replicated across studies from Denmark to Japan to the UK to Sweden. It is not that cycling is magical. It is that movement is necessary, and the bicycle makes consistent movement accessible to almost everyone, regardless of age, fitness level, or joint health.
“If exercise was a pill, everyone would be taking it. It has wide-ranging benefits for the body, the mind, for our muscles and our immune system.”
— Professor Norman Lazarus, King's College London, aged 82
What Cycling Does to Your Brain — And Why BDNF Is the Key
The most powerful argument for cycling is not what it does to your heart. It is what it does to your brain. And the mechanism begins with a protein called BDNF.
Aerobic exercise is one of the most effective ways known to increase BDNF — and cycling is one of the best aerobic exercises to achieve it.
BDNF (Brain-Derived Neurotrophic Factor) is a protein that supports the survival of existing neurons and promotes the growth of new brain cells — particularly in the hippocampus, the region responsible for memory formation and spatial navigation. The hippocampus is also one of the first regions to shrink in Alzheimer's disease.
Aerobic exercise — sustained, rhythmic, moderate-to-vigorous intensity activity — is one of the most reliable ways to increase circulating BDNF. Cycling, with its sustained cadence and adaptable intensity, is particularly effective at driving this response. Studies show that moderate-to-high intensity cycling for 30 to 45 minutes produces measurable increases in BDNF that persist hours after the ride.
The implications: regular cycling literally builds brain tissue. It is not metaphor. It is measurable neurogenesis — the creation of new neurons — in the part of the brain most vulnerable to aging and dementia.
Beyond BDNF: cycling also increases cerebral blood flow — delivering more oxygen and glucose to every region of the brain. It reduces neuroinflammation by calming microglial activity and lowering harmful cytokines. It produces structural increases in grey matter volume in the prefrontal cortex (executive function) and hippocampus. And the act of cycling itself — navigating roads, responding to traffic, adjusting pace — is dual-task cognitive training that engages executive functions in ways stationary exercise cannot replicate.
The Swedish Study — The Most Important Number in This Article
In 2018, researchers from the University of Gothenburg published a study in the journal Neurology that followed 191 Swedish women for 44 years — from midlife (age 38 to 60) all the way into their 90s. At the start, each woman completed a maximal ergometer cycling test to assess cardiovascular fitness. They were grouped into low, medium, and high fitness categories based on their peak wattage output.
The results: compared to medium fitness, high fitness was associated with an 88% lower risk of developing dementia over the 44-year follow-up. If the high-fitness women did eventually develop dementia, the average age of onset was 11 years later than in the medium-fitness group.
Eleven years. That is not a statistical footnote. That is an extra decade of clear memory, independent living, and cognitive function — won through cardiovascular fitness in midlife.
The researchers noted that the findings are associational, not causal. Other healthy habits may have contributed. But they added: “Consistent evidence suggests that interventions to prevent or treat cardiovascular disease may also improve brain health. What is good for the heart really does seem to be good for the brain.”
High vs medium cardiovascular fitness in midlife. 44-year Swedish study, Neurology 2018. Fitness measured by cycling ergometer.
Average delay in dementia onset for high-fitness women vs medium-fitness women. An extra decade of cognitive independence.
Aerobic cycling is one of the most effective known triggers for BDNF production — driving neurogenesis in the hippocampus, the brain's memory centre.
Regular aerobic exercise produces measurable increases in grey matter volume in the prefrontal cortex and hippocampus — the regions most affected by cognitive aging.
Cardiovascular Health — The Numbers Are Large
The evidence on cycling and cardiovascular health is among the most robust in exercise science. It spans Danish cohort studies tracking tens of thousands over decades, the massive UK Biobank study of over 263,000 adults, and a 14-year Danish study of 30,000 people that found regular cycling protected participants from heart disease.
The UK Biobank study of 263,450 adults, published in the BMJ in 2017, is the most comprehensive. Commuter cyclists had a 52% lower risk of dying from cardiovascular disease, a 46% lower risk of developing heart disease, and a 41% lower risk of dying from any cause compared to non-active commuters.
The mechanisms are well-understood: regular aerobic cycling strengthens the heart muscle, reduces resting heart rate and blood pressure, improves the lipid profile (reducing LDL, raising HDL), reduces arterial stiffness, improves endothelial function, and reduces systemic inflammation — the common background driver of most cardiovascular disease.
Importantly, the Danish data consistently shows a dose-response relationship: any cycling is better than none, but the first one to two hours per week delivers approximately twice the benefit per hour as subsequent hours. The biggest gains come from moving from zero to something — not from moving from a lot to more.
A 70-Year-Old With the Immune System of a 20-Year-Old
This finding, published in the journal Aging Cell in 2018, is the most biologically startling in the cycling research literature. Researchers at the University of Birmingham and King's College London studied 125 adults aged 55 to 79 who had cycled consistently throughout their adult lives. They compared them to 75 sedentary adults of the same age, and to 55 young adults aged 20 to 36.
The thymus glands of the older cyclists were the same size as those of people in their 20s.
The thymus is the gland responsible for producing T-cells — the immune system's primary soldiers against infection, autoimmune conditions, and cancer surveillance. The thymus normally begins to shrink from the age of 20, producing fewer and fewer T-cells with each passing decade. This immune decline — called immunosenescence — proceeds at approximately 2 to 3% per year.
In the older cyclists, the thymus had not shrunk. Its T-cell output was comparable to that of the young adult group, not the sedentary older adult group. Professor Janet Lord, co-author and Director of the Institute of Inflammation and Ageing at Birmingham, told the BBC: “Because the cyclists have the immune system of a 20-year-old rather than a 70- or 80-year-old, it means they have added protection against all these issues.”
The older cyclists also showed significantly higher levels of IL-7 — a cytokine that protects the thymus — and lower levels of IL-6, which promotes thymic atrophy. They had lower Th17 polarisation and higher B regulatory cell frequency, both indicating reduced immunosenescence.
Professor Steve Harridge, co-author and Professor of Physiology at King's College London: “Being sedentary goes against evolution because humans are designed to be physically active. You don’t need to be a competitive athlete to reap the benefits. Anything which gets you moving and a little bit out of puff will help.”
The Cancer Numbers and What Happens to Blood Sugar
Cancer Risk
The UK Biobank study found that cycling commuters had a 45% lower risk of developing cancer and a 40% lower risk of dying from cancer compared to non-active commuters. A meta-analysis of seven large cohort studies of over two million people found that 150 minutes of cycling per week was associated with a 10% reduction in all-cause mortality, with cancer mortality also significantly reduced.
The mechanisms are multiple: improved immune surveillance (the T-cell findings are directly relevant here), reduced chronic inflammation, improved hormonal regulation, reduced body fat (particularly visceral fat, which produces inflammatory cytokines), and improved insulin sensitivity — all of which are established factors in cancer risk reduction.
Type 2 Diabetes and Blood Sugar
The evidence on cycling and type 2 diabetes is consistent across multiple large cohort studies. Regular cycling improves insulin sensitivity, reduces fasting blood glucose, and reduces HbA1c. The Danish Diet, Cancer and Health cohort found that both recreational and commuter cycling were consistently associated with lower T2D risk across a study of over 50,000 adults. The dose-response relationship holds here too: any cycling reduces risk, and the effect compounds with consistency.
For those already managing blood sugar through diet and herbs, cycling is the complement that makes everything else work better. It increases GLUT4 receptor expression in muscle cells, improving glucose uptake without requiring insulin — a mechanism that directly addresses the core dysfunction of type 2 diabetes.
Weight, Blood Pressure, and Sleep
Regular cyclists show significantly lower resting blood pressure, improved lipid profiles (lower LDL, higher HDL, lower triglycerides), lower body fat percentage, and greater muscle mass compared to sedentary individuals of the same age. Sleep quality is consistently better in regular exercisers, with aerobic exercise associated with reduced time to sleep onset, longer slow-wave sleep, and improved overall sleep architecture. Better sleep means lower cortisol, better immune function, and better metabolic regulation — a compounding cycle that reinforces every other benefit.
Depression, Anxiety, and the Two-Wheel Prescription
The mental health evidence on cycling is consistent and mechanistically well-understood. Aerobic exercise produces endorphins, endocannabinoids, dopamine, serotonin, and norepinephrine — essentially the neurochemical profile that antidepressants are designed to approximate pharmacologically. Multiple meta-analyses have found that regular aerobic exercise is as effective as antidepressants for mild to moderate depression, and more effective at preventing relapse.
Cycling has specific advantages for mental health beyond general aerobic exercise: it gets you outdoors (sunlight and nature exposure independently improve mood), it involves navigation and spatial awareness (engaging cognitive systems beyond the default mode network associated with rumination), and the rhythmic, repetitive nature of pedalling produces a meditative state that quiets the anxious mind in ways static exercise does not.
A 2019 Oxford study of over 1.2 million people found that regular exercisers had 1.5 fewer poor mental health days per month than non-exercisers. Team sports and cycling showed the strongest associations. The effect was present across all demographics, ages, and income levels.
The Question Everyone Asks — Where Do I Start?
The research is clear on one thing above all others: consistency matters more than intensity, and something is vastly better than nothing. The Danish data shows the biggest health gains come from moving from zero to one to two hours per week — not from adding more to an already active life. You do not need to ride fast, far, or hard to access the benefits described in this article.
A Practical Cycling Guide — Starting From Zero
The goal is consistency, not performance. Start where you are.
Target: 2–3 rides of 15–20 minutes each.
Do not worry about speed, distance, or heart rate. Just get on the bike and pedal at a comfortable pace. A pace where you can hold a conversation is ideal. The goal is to establish the habit, not to achieve fitness. Ride anywhere: around the neighbourhood, to a warung, along a park path.
The science: even these short rides begin to produce BDNF within minutes of moderate aerobic activity. The first ride is pharmacological from the moment you begin.
Target: 3 rides per week, 25–40 minutes each.
Gradually extend the duration. Keep the intensity comfortable — you should be slightly out of breath but able to speak in short sentences. This is Zone 2 aerobic effort, the primary zone for fat oxidation, cardiovascular adaptation, and sustainable BDNF production.
By week 6, you will have accumulated approximately 5–6 hours of riding. Research shows measurable cardiovascular improvements begin to appear within 4–6 weeks of consistent aerobic training.
If you can cycle to work: this is the highest-yield option.
The UK Biobank study showing 41% lower premature mortality was based primarily on commuter cyclists — people who cycled to work, not athletes training for events. Folding the ride into a journey you are already making removes the scheduling problem entirely. Even partial cycling (cycle to the LRT, take the train, cycle the last stretch) counts as mixed-mode cycling and was also associated with significantly lower mortality in the research.
If terrain, distance, or fitness level is a barrier: use an e-bike.
Research confirms that e-bike riders still elevate their heart rates into the moderate aerobic zone necessary for BDNF production, cardiovascular benefit, and immune system maintenance. The electric assist makes longer distances and hillier terrain accessible, which means more time on the bike and more consistent habits.
If an e-bike gets you out three times a week instead of zero times on a conventional bike, the e-bike is the better health intervention. Do not let perfect be the enemy of done.
The WHO recommends 150–300 minutes of moderate aerobic activity per week.
At a comfortable cycling pace, this is approximately 25–45km per week, split across however many rides fit your schedule. Five 30-minute rides. Three 50-minute rides. Two 75-minute rides. The specific pattern matters less than hitting the total consistently each week.
The Danish research shows the curve flattens after this threshold — you get the most benefit from the first 150 minutes, and diminishing (but still real) returns thereafter.
For those with knee, hip, or ankle concerns: cycling is the prescription.
Unlike running, cycling is a non-impact activity. The pedalling motion drives the joints through their full range of motion without the compressive loading that damages cartilage in high-impact exercise. Research confirms that regular cycling does not increase osteoarthritis risk and may reduce it by maintaining joint lubrication and the surrounding musculature. For anyone over 50, or anyone with existing joint concerns, the bicycle provides aerobic exercise that running cannot.
What Is True, Overstated, and Simply Wrong About Cycling
“Cycling is dangerous. You will get hit by a car.”
Danish researchers calculated that the health benefits of cycling are 238 times greater than the mortality risk from cycling accidents. This was not a small sample — it was calculated using national data on cycling rates, accident rates, and the documented health benefits from large cohort studies. The risk of NOT cycling — cardiovascular disease, dementia, cancer, immune decline — vastly outweighs the risk of cycling. Risk perception around cycling is driven by the vividness of accident scenarios, not by the actual mortality data. Ride safely. Wear a helmet. Use lights. But ride.
“You need to ride hard and fast for it to count.”
The Danish cohort data found that even 1 to 60 minutes of recreational cycling per week was associated with a 22 to 24% lower all-cause mortality risk compared to non-cyclists. The UK Biobank commuter cyclists were not racing — they were riding to work at normal commuting pace. The Swedish women whose fitness reduced dementia risk by 88% were not elite athletes. The University of Birmingham immune study cyclists were amateurs riding about 60 miles a week at normal pace. Moderate, consistent, and sustainable beats intense and occasional every time.
“I am too old to start cycling.”
The 2025 Japanese 10-year study specifically examined what happened when older adults began or continued cycling. Those who initiated cycling showed significantly lower risk of requiring long-term care or facing premature death. The Danish study of 28,204 people found that those who initiated cycling late in mid-life had a hazard ratio of 0.78 for all-cause mortality — a 22% lower risk — compared to people who never started. Starting late delivers real benefits. The body's adaptive response to aerobic exercise does not expire. Biology does not care when you begin. It responds when you do.
“E-bikes don't count. It's cheating.”
Research confirms that e-bike riders still elevate their heart rates into the moderate aerobic zone necessary for BDNF production, cardiovascular benefit, and the immune system maintenance documented in the Aging Cell study. E-bikes make cycling accessible to people for whom conventional bikes are not realistic: those with knee conditions, those returning from injury, older adults managing hills, commuters covering longer distances. If an e-bike gets someone cycling three times a week who would otherwise not cycle at all, it delivers the full range of metabolic, cardiovascular, and cognitive benefits. The assist changes the effort, not the physiological response.
“Cycling damages the knees.”
Cycling is consistently among the lowest-impact aerobic activities for joint health. Unlike running, it produces no ground-reaction compressive force on the knee joint. Cycling actually helps maintain joint health by lubricating the joint through range of motion and by strengthening the surrounding musculature that protects the knee. The one nuance: poor bike fit — particularly a saddle that is too low — can cause knee problems. A properly fitted bike is essentially knee-friendly by design. For people with existing knee conditions, cycling is often recommended as the aerobic exercise of choice specifically because it is non-impact.
“Cycling is good for mental health.”
The 2019 Oxford study of 1.2 million people found exercisers had 1.5 fewer poor mental health days per month. Cycling and team sports showed the strongest associations. The mechanisms are pharmacological: aerobic cycling produces endorphins, endocannabinoids, dopamine, serotonin, and norepinephrine — the same neurochemical targets as antidepressant medications. Multiple meta-analyses have found aerobic exercise comparable to antidepressants for mild to moderate depression, with superior relapse prevention. Add the outdoor exposure, the meditative rhythm, and the spatial cognition of real-world navigation, and cycling's mental health benefit exceeds what a purely aerobic perspective would predict.
“More cycling is always better.”
The dose-response curve for cycling and health benefits is non-linear. The first one to two hours per week produces approximately twice the benefit per hour as subsequent hours. Beyond the WHO-recommended 150 minutes per week, benefits continue to compound, but the marginal gain per additional hour decreases. At very high training volumes (elite endurance cyclists, multi-day events), the immune system can be temporarily suppressed and overuse injuries become a consideration. The sweet spot for health — not performance — is consistent moderate-volume cycling, not maximal volume cycling.
What is well-documented: Strong inverse relationship between cycling and all-cause mortality, cardiovascular mortality, and cancer mortality across multiple large prospective cohort studies. 88% lower dementia risk with high cardiovascular fitness (44-year study, fitness measured by cycling ergometer). Immune system maintenance — T-cell production of a 20-year-old at age 70–80 (Aging Cell, 2018). Significant BDNF production and neuroplasticity benefits. Lower type 2 diabetes incidence. Improved lipid profiles, blood pressure, sleep quality. Mental health benefits comparable to antidepressants for mild-moderate depression.
What to note: Most large studies are observational (cohort studies), not randomised controlled trials — association does not equal causation, and healthier habits tend to cluster. People who cycle may also eat better, smoke less, and have lower chronic stress. The studies attempt to control for confounders, but residual confounding remains possible. That said, the consistency, scale, and mechanistic plausibility of the findings is as strong as any evidence base in preventive medicine.
The bottom line: The data on cycling is not marginal. It is among the most consistent and largest-effect evidence in exercise science. The biological mechanisms are understood. The practical barriers are low. The bicycle is one of the most accessible health interventions available to most humans on earth, and the research suggests it may be one of the most powerful.
If you have existing cardiovascular conditions, significant joint problems, or have been sedentary for an extended period, check with your doctor before beginning a cycling programme. Start with short, easy rides and increase duration gradually. Wear a helmet. Use lights if riding near traffic. Ensure your bike is properly fitted — saddle height, reach, and handlebar position all affect both comfort and injury prevention. Stay hydrated in Malaysian heat and avoid riding in the hottest part of the day. If you have diabetes and are on medication, monitor your blood sugar, as aerobic exercise can significantly affect glucose levels.
References & Sources (click to expand)
- Hörder, H. et al. (2018). Midlife cardiovascular fitness and dementia: A 44-year longitudinal population study in women. Neurology, 90(15). PMC5894933. [88% dementia risk reduction finding]
- Celis-Morales, C.A. et al. (2017). Association between active commuting and incident cardiovascular disease, cancer, and mortality: prospective cohort study. BMJ, 357:j1456. [263,450 participants, UK Biobank — 41% lower mortality, 52% lower CVD death, 45% lower cancer incidence]
- Duggal, N.A. et al. (2018). Major features of immunesenescence, including reduced thymic output, are ameliorated by high levels of physical activity in adulthood. Aging Cell, 17(2). PMC5847865. [T-cells of a 20-year-old in 70-year-old cyclists]
- Tsunoda, K. et al. (2025). Changes in cycling and incidences of functional disability and mortality among older Japanese adults. Transportation Research Part F, March 2025. DOI: 10.1016/j.trf.2025.03.006.
- Østergaard, L. et al. (2018). Associations Between Changes in Cycling and All-Cause Mortality Risk. American Journal of Preventive Medicine, 55(5):615–623. [28,204 Danish participants]
- Oja, P. et al. (2011). Health benefits of cycling: a systematic review. Scandinavian Journal of Medicine & Science in Sports, 21(4):496–509. PMC21496106. [Systematic review, strong inverse relationship with all-cause mortality and cancer mortality]
- Andersen, L.B. et al. (2018). Trends in cycling and cycle related injuries and a calculation of prevented morbidity and mortality. Journal of Transport & Health, 9. [238x health benefit over accident risk finding]
- Chekroud, S.R. et al. (2019). Association between physical exercise and mental health in 1.2 million individuals in the USA. Lancet Psychiatry, 5(9):739–746. [1.5 fewer poor mental health days per month]
- World Health Organization (2020). WHO Guidelines on Physical Activity and Sedentary Behaviour. WHO Press. [150–300 minutes per week recommendation]
- Blond, K. et al. (2016). Prospective study of bicycling and risk of coronary heart disease in Danish men and women. Circulation, 134(18):1409–1411.