Heart health and lifestyle — what the evidence actually says

The current evidence-based target for most healthy adults is 150 minutes of moderate-intensity aerobic activity (brisk walking, cycling, swimming) or 75 minutes of vigorous activity (running, fast cycling, sport) per week, plus at least two sessions of resistance training (weights, bodyweight exercises).

Even less helps. Just 75 minutes a week of moderate activity reduces cardiovascular mortality by around 15%, and the dose–response curve is steep at the lower end — going from zero to some activity matters more than going from a lot to even more. Long sedentary periods (more than 8 hours of sitting a day) are independently harmful, so short standing or walking breaks during the working day help meaningfully.

Yes — and you almost certainly should. Regular exercise reduces the risk of further events by around 25% in patients with established coronary disease and is one of the central pillars of cardiac rehabilitation. The intensity and timing depend on the type and severity of your condition.

After a heart attack or stent, supervised cardiac rehabilitation is the safest starting point and is offered through both NHS and private programmes. After stable diagnoses — well-controlled angina, treated AFib, mild heart failure on optimal medication — most patients can build up to standard moderate exercise. If you are uncertain about specific activities, the answer is almost always more activity, sensibly progressed, not less.

No — moderate coffee consumption (up to 3–4 cups a day) is not harmful to the heart in most people and may even be associated with modestly reduced cardiovascular and all-cause mortality. The earlier concerns about coffee and heart disease have been largely overturned by larger, better-controlled studies.

The exceptions are people who are very caffeine-sensitive — particularly those prone to ectopic beats, palpitations, anxiety or insomnia — for whom even small amounts can be triggering. Pregnant women should limit caffeine to under 200 mg a day (roughly two cups). Energy drinks with very high caffeine doses combined with other stimulants are a different matter entirely and are best avoided.

The current UK guideline is no more than 14 units a week, spread over at least three days, with several genuinely alcohol-free days each week. The earlier idea that "a glass of red wine is good for your heart" is no longer well supported — the cardiovascular benefit of light drinking, if it exists at all, is much smaller than once thought.

Alcohol is a clear cause of high blood pressure, atrial fibrillation, weight gain and cardiomyopathy at higher intakes, and even moderate intake raises cancer risk. The least-risk approach for the heart is to drink less, or not at all. If you do drink, staying within UK guidelines and having genuinely alcohol-free days matters more than the type of drink.

The two diets with the strongest evidence for cardiovascular benefit are the Mediterranean diet and the DASH diet. Both emphasise vegetables, fruit, wholegrains, pulses, nuts, olive oil and oily fish, with limited red and processed meat, refined carbohydrates and ultra-processed foods.

The Mediterranean diet has been shown in randomised trials to reduce cardiovascular events by around 30%, with benefits appearing within months of adoption. The single highest-impact dietary change for most people is reducing ultra-processed foods — ready meals, sugary drinks, processed meats, confectionery — which now make up over half of UK calorie intake. You don't need to be perfect; directionally better matters more than orthodoxy.

Yes — chronic stress is an increasingly recognised independent risk factor for cardiovascular disease, through effects on blood pressure, inflammation, sleep, behaviour (eating, drinking, smoking) and the autonomic nervous system. Acute severe stress can also trigger heart attacks and a stress-induced heart muscle weakness called takotsubo cardiomyopathy ("broken heart syndrome").

Effective stress management — exercise, sleep, social connection, time outdoors, mindfulness, professional support where needed — is part of cardiovascular prevention, not an optional extra. Loneliness and social isolation in particular carry cardiovascular risk comparable to smoking, and are too rarely addressed in clinical consultations.

Very. Adults who routinely sleep less than 6 hours a night have a 20–30% higher risk of cardiovascular events, even after accounting for other risk factors. The optimal duration for most adults is 7 to 9 hours, with consistent timing as important as total duration.

Equally important is sleep quality. Untreated obstructive sleep apnoea is a major and under-diagnosed cause of high blood pressure, atrial fibrillation, heart attacks and strokes. If you snore heavily, wake unrefreshed, fall asleep during the day or are overweight, a sleep study is worth considering. Treating sleep apnoea is one of the most impactful single interventions available in preventive cardiology.

For most patients, yes — and often sooner than people expect. Sexual activity can typically resume around 2–4 weeks after an uncomplicated heart attack, once you can comfortably climb two flights of stairs without symptoms. The cardiovascular demand of sex is roughly equivalent to brisk walking.

Performance issues after a cardiac event are common, often related to medications (beta-blockers, some antihypertensives) or anxiety rather than the heart itself. Most can be addressed — speak openly to your cardiologist. PDE5 inhibitors (sildenafil and similar) are safe in most cardiac patients but must not be combined with nitrates (GTN spray or tablets) — this combination can cause a dangerous drop in blood pressure.

Yes — modern smartwatches with optical heart rate sensors and single-lead ECG (available on Apple Watch Series 4 and later, Fitbit Sense, Withings ScanWatch and others) can reliably detect persistent atrial fibrillation, sustained high or low heart rates, and broad changes in resting heart rate trends. Their main value is continuous monitoring during normal life — capturing intermittent episodes that a single clinic recording would miss.

Limitations: they are less accurate during vigorous movement or for arrhythmias other than AFib, they generate false positives, and they cannot diagnose heart attacks or assess coronary arteries. Used sensibly, with results reviewed by a cardiologist when relevant, smartwatches are a genuine and growing addition to modern cardiac care.

The single-lead ECG feature on the Apple Watch, Fitbit Sense, Withings ScanWatch and similar devices has been validated in multiple studies for detecting atrial fibrillation, with sensitivity and specificity above 95% in controlled testing. The tracings are clear enough to be interpreted clinically and have been used successfully in both research and routine practice.

What they do well: confirm AFib in a symptomatic patient, detect ectopic beats, measure resting heart rate trends. What they cannot do: rule out a heart attack, assess coronary artery disease, or replace a 12-lead ECG for complex rhythm diagnoses. I regularly review smartwatch tracings brought in by patients and they often save weeks of diagnostic investigation — they are a tool I actively encourage.