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Improve your cardiovascular fitness: a pair of worn running shoes, a steel water bottle, a folded towel and a small stopwatch on a wooden bench beside a sunlit tree-lined trail

Support Your Heart & Circulation

Improve Your Cardiovascular Fitness

Cardiovascular (aerobic) fitness is how well your heart, lungs and blood vessels deliver oxygen to working muscles, and it can be improved at almost any age with regular, gradually increased activity. This page is about building that fitness safely; blood pressure, cholesterol, circulation, diet and sitting time have their own goal pages.

General information, not medical advice. Last updated October 31, 2026. Written by the AlternativeMed editorial team. Not medically reviewed.

Start here

  • Aim for a weekly total, not a perfect workout: health agencies suggest at least 150 minutes of moderate activity (or 75 minutes of vigorous activity) a week, and any amount is better than none.
  • Use the talk test to set the effort: at a moderate pace you can talk but not sing; at a vigorous pace you can only say a few words before pausing for breath.
  • If you have been inactive, have a medical condition or are unsure, check with your doctor first, start with short easy sessions, and build up gradually.

Be careful with

  • Chest pain, pressure or tightness, severe breathlessness, dizziness or faintness while exercising means stop and get medical help; do not push through.
  • Vigorous exertion by people who are unfit can briefly raise the risk of a heart event, so build up in steps and get advice first if you have heart disease, diabetes, high blood pressure or other conditions.
  • Do not stop, reduce or change any prescribed medicine because you have started exercising; some medicines change how your heart rate responds, so ask your prescriber how to judge effort.
  • Be wary of products promising to boost stamina or fitness without exercise; none replaces regular activity.

Get help when

  • Chest pain that feels tight or squeezing, or severe breathing difficulty: the NHS says to call 999 (UK) and not to drive yourself to hospital; in other countries use your local emergency number.
  • Face drooping, weakness or numbness in one arm, slurred or confused speech: the NHS says to call 999 straight away, even if the signs pass within 24 hours.
  • Pain, extreme shortness of breath or dizziness during activity: MedlinePlus advises stopping and getting help right away.
  • Breathlessness, tiredness or a racing or irregular heartbeat with everyday tasks that is new or getting worse: see a doctor promptly.
  • Fitness that does not improve, or exhaustion that gets worse after activity, which can have medical causes.

About Improve Your Cardiovascular Fitness

What this goal means

Cardiovascular fitness (also called cardiorespiratory or aerobic fitness) describes how well the heart, lungs and blood vessels work together to supply oxygen during sustained activity. In research it is usually measured as peak oxygen use or as treadmill performance, and expressed in METs, where 1 MET is the energy used sitting quietly.

Improving it means being able to do more, for longer, at an easier effort: climbing stairs, walking briskly, playing with children or finishing a walk without being out of breath.

1,2,3

What it can feel like

Common signs of lower fitness are getting out of breath on stairs or a short brisk walk, a heart rate that jumps quickly with effort, and taking a long time to feel normal again afterwards. As fitness builds, the same effort tends to feel easier.

These are everyday experiences, not a diagnosis. Breathlessness that is sudden, severe or new has medical causes that need checking.

4,5

What shapes fitness

Regular aerobic activity is the main factor you can change. The amount, intensity and consistency of activity all matter. Long periods of sitting are a separate risk and are covered on the Sit Less & Move More page.

Age, body size, health conditions, some medicines, sleep and illness also affect how fast fitness improves. Conditions such as sleep apnea can leave you short of energy for exercise.

6,7,8

Related conditions

People with heart disease, high blood pressure, diabetes, lung disease or joint problems can often still be active, but should plan the type and intensity with their care team. Cardiac rehabilitation programs exist for people with coronary heart disease and are supervised and tailored.

If your tiredness is out of proportion to your activity, or gets worse after exertion, see the pages on persistent fatigue and ME/CFS before pushing harder.

9,4

Realistic expectations

Fitness improves over weeks and months, not days. In a trial of people with stable coronary artery disease, 8 weeks of supervised training raised peak oxygen uptake by about 1.3 to 2.4 mL/kg/min depending on the type of training, a real but modest change in two months.

Most of the benefit in the large studies read comes from reaching the recommended weekly amount; going well beyond it added smaller extra benefit.

10,11

Who this applies to

Healthy adults who want more stamina, and adults who are inactive, overweight, older or living with long-term conditions, with appropriate medical advice. Pregnancy and postpartum have specific WHO guidance, and children and teenagers need different amounts, so those groups should use age-specific advice.

6,5

Related conditions and symptoms

Obesity and weight-related health → Prediabetes, type 2 diabetes and metabolic syndrome → Sleep apnea → ME/CFS and post-exertional malaise → Fatigue: when to get help →

A manageable starting plan

An educational starting point, not a personal prescription. Adjust it to your own situation and any advice from your clinician.

Your first actions

  • If you have a medical condition, symptoms or have been inactive for a long time, speak to a doctor first.
  • Pick an activity you enjoy and do 10 minutes of easy-to-moderate effort on most days.
  • Add about 5 minutes a week until you reach 150 minutes of moderate activity a week or an equivalent amount.
  • Use the talk test: you should be able to talk but not sing at a moderate pace.

Optional additions

  • Add two strength sessions a week.
  • After a few weeks of steady activity, try short faster efforts with easy recovery, if your doctor agrees.
  • Break up long sitting with short walks.
  • Join a class, club or walking group for support.

What to track

  • Minutes of activity each week and how hard it felt (talk test or 0 to 10 scale).
  • How easy everyday tasks feel, such as stairs or a regular walk.
  • Any symptoms during or after activity.

When to reassess

Check progress every 4 to 8 weeks. If the same walk feels easier, you are improving. If you have symptoms, see no progress for months, or feel worse after activity, see a doctor.

When to seek professional support

  • Ask your doctor about safe activity levels, and about cardiac rehabilitation if you have heart disease.
  • Ask a physiotherapist or qualified exercise professional for a tailored plan if you have joint or mobility problems.

What helps

Ordered by how well the research supports each step. Evidence strength is shown on every card; precautions sit next to the advice.

Start here

Build up to 150 minutes of moderate (or 75 of vigorous) aerobic activity a week

High certainty

Addresses: Higher aerobic fitness and lower risk of heart disease over time

Why it may help: The NHS and CDC both give 150 minutes of moderate or 75 minutes of vigorous activity a week as the adult target, and the WHO 2020 guideline gives 150 to 300 minutes of moderate or 75 to 150 minutes of vigorous activity, or an equivalent mix. The NHS lists lower risk of coronary heart disease and stroke among the benefits of regular exercise. NHLBI says activity can help lower LDL cholesterol and blood pressure. Much of this evidence is from large observational studies and guideline reviews rather than one trial.

How to apply it: Spread it through the week, for example 30 minutes on 5 days, or shorter sessions that add up. Brisk walking, cycling and swimming all count. Start where you are and add a few minutes at a time.

Who it may suit: Most adults, including those with many long-term conditions, with medical advice where needed.

Precautions: Check with a doctor first if you have been inactive, have a health condition or are unsure what is safe.

5,12,6,8,13

Activity, strength and muscle → Improve Your Everyday Stamina →

Use the talk test (and effort scale) to pick the right intensity

Moderate certainty

Addresses: Lets you match effort to your fitness without a gadget

Why it may help: Moderate activity means you can talk but not sing; vigorous means you can say only a few words before pausing for breath (NHS, CDC). The CDC also describes a 0 to 10 effort scale where moderate is about 5 or 6 and vigorous about 7 or 8, and notes it is relative to your own fitness.

How to apply it: Work at a pace where you can hold a conversation for most sessions. Include a short faster stretch only when that feels comfortable.

Who it may suit: Everyone, including people who do not use a heart-rate monitor.

Precautions: Some medicines change heart rate, so a pulse number may mislead; ask your prescriber how to gauge effort.

5,1

Start low and go slow if you have been inactive

Moderate certainty

Addresses: Reduces the chance of injury or a setback and makes the habit stick

Why it may help: MedlinePlus advises starting slowly if you have not exercised in a while, building the habit and increasing activity gradually, with short sessions still counting. The CDC says some physical activity is better than none and suggests breaking activity into smaller chunks.

How to apply it: Begin with 5 to 10 minute walks, add a few minutes each week, and choose activities you enjoy. Rest days are part of the plan.

Who it may suit: People new to exercise, returning after illness, older adults.

Precautions: If you have symptoms or a medical condition, ask a doctor before increasing intensity.

4,12

Recovery after exercise →

Choose a mix of activities you will actually keep doing

Low certainty

Addresses: Better consistency, which is what drives fitness

Why it may help: MedlinePlus advises choosing enjoyable activities, mixing workouts to stay interested and reduce injury or burnout, setting realistic goals and finding an accountability partner. It describes aerobic activity as keeping the heart, lungs and circulation healthy.

How to apply it: Pick two or three options (a walk, a bike ride, a class, swimming) and put them in your calendar.

Who it may suit: Anyone finding it hard to stay consistent.

Precautions: Protect yourself from sun and dress for the weather when outdoors.

4

Additional options

Add strength training on 2 days a week

High certainty

Addresses: Complements aerobic work and keeps muscles strong enough to be active

Why it may help: The NHS, CDC and WHO all recommend muscle-strengthening activity on at least 2 days a week alongside aerobic activity, working all major muscle groups. This supports activity but is a separate goal from aerobic fitness.

How to apply it: Use body weight, bands or weights. See the strength page for how to start.

Who it may suit: Most adults; older adults especially.

Precautions: Learn technique first; people with joint or heart conditions should ask for guidance.

5,12,6

Activity, strength and muscle →

Try interval training once the basics are steady

Moderate certainty

Addresses: May raise aerobic fitness a little more than steady exercise in some groups

Why it may help: In a meta-analysis of 10 studies (273 people with conditions such as coronary artery disease, heart failure, hypertension, metabolic syndrome or obesity), interval training raised peak oxygen uptake by about 3 mL/kg/min more than continuous moderate training. In a trial of 382 people with stable coronary artery disease in cardiac rehabilitation, a low-volume interval program (10 one-minute hard efforts with one-minute recoveries, twice weekly for 8 weeks) improved fitness more than moderate steady exercise, and only one serious adverse event was possibly related to it. Another meta-analysis found interval and steady training gave similar fat-mass and waist reductions in overweight adults, with intervals taking about 40% less time.

How to apply it: Alternate short faster efforts with easy recovery, for example a minute brisk then a minute easy, repeated several times, after a few weeks of steady activity. Keep the first efforts well within your limits.

Who it may suit: Adults who are already regularly active; people with heart disease only in supervised programs.

Precautions: The cardiac trial was supervised in rehabilitation centres. Vigorous exertion can briefly raise the risk of cardiac events in susceptible, unfit people; get medical advice first if you have any heart condition or risk factors.

14,10,15,16

Take part in supervised cardiac rehabilitation if you have coronary heart disease

High certainty

Addresses: Lower risk of heart attack and hospital admission in the studies

Why it may help: A Cochrane review of 85 trials (23,430 people with coronary heart disease) found exercise-based cardiac rehabilitation produced a large reduction in heart attack (relative risk 0.72, high certainty) and in all-cause hospital admission (0.58, moderate certainty) at 6 to 12 months, with a slight, uncertain effect on death from any cause.

How to apply it: Ask your doctor or heart team about referral; programs are tailored and supervised.

Who it may suit: People who have had a heart attack, bypass or stent, or have stable coronary disease.

Precautions: Only start exercise after a heart event with your care team's plan.

9

Break up long periods of sitting, even when you exercise

Moderate certainty

Addresses: Reduces the extra risk linked with sitting

Why it may help: A pooled analysis of more than 1 million people found that about 60 to 75 minutes a day of moderate activity seemed to remove the higher death risk linked to long daily sitting, although it only reduced the risk linked to heavy TV viewing. The NHS says sitting for long periods is harmful even if you meet your weekly target, and the WHO recommends reducing sedentary time without setting a threshold.

How to apply it: Stand, stretch or walk for a few minutes regularly; see the sitting page for ideas.

Who it may suit: Desk workers and anyone who sits much of the day.

Precautions: Observational data; amounts were self-reported.

7,8,6

Sit Less & Move More →

Keep it going: more is only modestly better

Moderate certainty

Addresses: Most of the benefit arrives at the recommended minimum

Why it may help: A pooled analysis of leisure-time activity studies (Arem et al.) found a 20% lower mortality risk below the recommended minimum, 31% lower at 1 to 2 times the minimum and 37% lower at 2 to 3 times; the benefit levelled off at 3 to 5 times the minimum, with no excess risk seen at 10 or more times. A treadmill-test cohort of 122,007 patients found higher fitness linked with lower mortality with no upper limit seen.

How to apply it: Aim first for the weekly minimum; add more only if you enjoy it.

Who it may suit: Active adults wondering how much is enough.

Precautions: These are observational studies; they show association, not proof of cause. An American Heart Association statement notes that very large exercise volumes and intensities have been linked to some cardiac changes.

11,17,16

Still being studied

Fitness as a health measure

Moderate certainty

Addresses: Higher fitness tracks with lower risk in large cohorts

Why it may help: A meta-analysis of 33 cohort studies found each 1-MET higher fitness was linked to about 13% lower all-cause mortality and 15% lower heart disease and cardiovascular events, and low fitness carried about 1.7 times the death risk of high fitness. An American Heart Association statement notes fitness may predict mortality better than some traditional risk factors and suggests assessing it in clinical practice.

How to apply it: Ask your doctor whether a fitness test (such as a treadmill test) is appropriate for you; it is not something to self-diagnose.

Who it may suit: Adults who want to understand their baseline.

Precautions: Association, not proof; people who are fitter may differ in other ways.

2,3,17

Food & nutrition

Eating and drinking around activity

The sources read for this page did not give specific meal or drink advice for building aerobic fitness, so none is made here. Heart-healthy eating has its own page, and weight, appetite and blood sugar are covered under the Healthy Weight goals.

People with diabetes should ask their care team how activity affects their medicines and meals.

4

Foods that have been studied for exercise performance

No food has been shown to build fitness without exercise. One nitrate-rich food has controlled-trial evidence for short-term performance, rated low certainty below.

Beetroot juice (dietary nitrate)

Low certainty

Addresses: Longer time to exhaustion in some tests

Why it may help: A meta-analysis of 17 controlled studies of nitrate (mostly beetroot juice and sodium nitrate) found a moderate benefit for time-to-exhaustion tests and small, not statistically significant effects on time trials and graded exercise tests. Benefits were more often seen in inactive to recreationally active people.

How to apply it: Studied as beetroot juice or nitrate salts as a single dose up to about 15 days; no dose is recommended here.

Who it may suit: Recreationally active adults curious about performance.

Precautions: Short, small studies in healthy people. If you take blood-pressure or heart medicines, ask a pharmacist before using nitrate supplements.

18
18

Remedies & supplements

Traditional use, laboratory findings and human trials are kept apart. "Natural" does not mean safe.

Nitrate supplements (beetroot juice)

Low certainty

Studied form and route: Beetroot juice or nitrate supplements

Intended outcome: Longer time to exhaustion in lab tests

Human evidence: A meta-analysis of 17 controlled human studies found a moderate benefit on time-to-exhaustion tests (effect size 0.79) but no clear benefit on time trials or graded exercise tests.

Traditional use: Beetroot is a traditional food; its use as a sport supplement is modern.

Laboratory findings: Mechanisms were not reviewed for this page.

Limits: Small studies in healthy people; effects most often seen in less-trained individuals; the best way to use it is unclear.

Interactions and precautions: Ask a pharmacist if you take blood-pressure or other heart medicines. Not a substitute for training.

18

Coenzyme Q10

Not enough evidence

Studied form and route: Oral supplement

Intended outcome: Claimed energy and stamina

Human evidence: No trials of coenzyme Q10 for building cardiovascular fitness were reviewed for this page, so no benefit can be claimed.

Limits: Not examined in this research round.

Interactions and precautions: Ask a pharmacist before use if you take any medicine, especially blood thinners or heart medicines.

Coenzyme Q10 →

Hawthorn and other 'heart tonic' herbs

Not enough evidence

Studied form and route: Herbal extracts

Intended outcome: Claimed improved circulation or exercise capacity

Human evidence: No trials of these herbs for building aerobic fitness in healthy people were reviewed for this page.

Traditional use: Hawthorn and arjuna have traditional use as heart tonics.

Limits: Traditional use is not proof of benefit.

Interactions and precautions: Herbs marketed for the heart can interact with prescribed heart and blood-pressure medicines; check with a pharmacist and never replace prescribed treatment.

Hawthorn → Arjuna →

Therapies & care

Established professional care for building fitness safely includes a doctor's check if you are inactive or have conditions, supervised cardiac rehabilitation after a heart event, and physiotherapists or qualified exercise professionals for tailored plans. This page does not recommend medicines or doses, and no prescribed medicine should be stopped or changed without the prescriber.

Cardiac rehabilitation

High certainty

Supervised exercise and education program A Cochrane review of 85 trials found exercise-based rehabilitation reduced heart attack and hospital admissions in people with coronary heart disease.

Who it may suit: People after a heart attack, bypass or stent, or with stable coronary disease.

Precautions: Enter through your heart team; intensity is individualized.

9,10

Pre-exercise medical check

Moderate certainty

Medical assessment The NHS advises seeing a GP first if you have not exercised in a while or have a condition; MedlinePlus advises checking with a provider before starting if you are unsure it is safe.

Who it may suit: Inactive adults, older adults, anyone with risk factors or symptoms.

Precautions: Report chest pain, breathlessness, fainting or palpitations.

5,4,16

Fitness testing

Moderate certainty

Clinical assessment An American Heart Association statement suggests measuring fitness may improve risk prediction and encourage lifestyle change.

Who it may suit: Adults whose clinician recommends it.

Precautions: Supervised testing only.

3,17

What to avoid

Habits, products and claims that can get in the way. Never stop a prescribed medicine without talking to the professional who prescribed it.

Risks that apply to most people

Going from no exercise to intense exercise overnight

Moderate certainty

Why: Vigorous activity, particularly in unfit people, can briefly raise the risk of sudden cardiac death and heart attack in susceptible people, according to an American Heart Association statement.

Who it applies to: Previously inactive adults, older adults, people with risk factors.

Try instead: Build up in steps, starting with easy walking, and get medical advice if you have a heart condition or risk factors.

16,4

Ignoring warning symptoms during activity

High certainty

Why: Pain, extreme breathlessness or dizziness are reasons to stop and get help (MedlinePlus), and chest pain that is tight or squeezing needs an emergency call (NHS, 999 in the UK).

Who it applies to: Everyone; especially people with risk factors.

Try instead: Stop, rest, and seek medical help; do not push through or drive yourself.

4,19

Relying on a tracker's numbers without checking effort

Low certainty

Why: Health guidance is stated in minutes of moderate or vigorous effort, and intensity is judged by talk test or effort scale.

Who it applies to: People using gadgets as their only measure.

Try instead: Use the talk test as a check alongside any device.

5,1

Long unbroken sitting

Moderate certainty

Why: The NHS says prolonged sitting is harmful even if you meet your activity target.

Who it applies to: Desk workers and people who watch long stretches of TV.

Try instead: Stand or move briefly at regular intervals.

8,7

Sit Less & Move More →

Personal triggers to check

Exercising through illness or a racing or irregular heartbeat

Moderate certainty

Why: The NHS lists a racing or irregular heartbeat with chest pain or sickness as a reason to call NHS 111 (UK). Feeling unwell is a reason to rest and get advice.

Who it applies to: Anyone unwell or with palpitations.

Try instead: Rest and get advice; return gradually.

19,4

Pushing harder when activity makes you much worse afterwards

Low certainty

Why: A pattern of worsening symptoms after activity needs a medical assessment rather than more exercise.

Who it applies to: People with unexplained exhaustion or suspected ME/CFS.

Try instead: Pace activity and see a clinician.

4

ME/CFS and post-exertional malaise → Fatigue: when to get help →

Products that need caution

Stimulant-style 'stamina' or fat-burner products promising fitness gains

Not enough evidence

Why: No product in the sources read replaces regular aerobic activity, and no evidence for such products was found in them. Stimulants can raise heart rate.

Who it applies to: People tempted by quick fixes.

Try instead: Spend the effort on regular activity; ask a pharmacist before using any stimulant or supplement, especially with heart conditions or medicines.

5

Unsupervised intense programs if you have heart disease

Moderate certainty

Why: The interval-training trial in heart patients took place in supervised rehabilitation.

Who it applies to: People with coronary disease, heart failure or arrhythmia.

Try instead: Ask for cardiac rehabilitation or a tailored plan.

10,9

Unsupported claims

'Exercise alone can cure heart disease or unblock arteries'

Evidence against

Why: No such effect was found in the sources read. Exercise lowers risk and improves fitness, and cardiac rehabilitation reduces future events, but it is not a cure.

Who it applies to: Anyone choosing between exercise and medical treatment.

Try instead: Keep taking prescribed medicines and use exercise alongside medical care.

9,8

'You have to train very hard to benefit'

Moderate certainty

Why: Studies show most benefit arises at the recommended minimum, and the CDC says some activity is better than none.

Who it applies to: People who feel they cannot do enough.

Try instead: Start with what you can do.

11,12

'Standing or sitting less is enough on its own'

Moderate certainty

Why: Guidelines recommend both reducing sitting and weekly aerobic activity.

Who it applies to: Desk workers.

Try instead: Do both.

6,5

Common mistakes

Doing too much too soon

Low certainty

Why: MedlinePlus advises starting slowly and increasing gradually; sudden big increases raise the chance of injury or giving up.

Who it applies to: New exercisers.

Try instead: Add a few minutes a week.

4

Only doing one kind of activity

Low certainty

Why: MedlinePlus describes aerobic, strength, balance and flexibility work as a mix that most people benefit from.

Who it applies to: Single-activity exercisers.

Try instead: Mix activities.

4,5

Stopping prescribed medicines because you feel fitter

High certainty

Why: Exercise is not described as a replacement for prescribed treatment; a doctor decides any change.

Who it applies to: People with high blood pressure, cholesterol or heart conditions.

Try instead: Tell your prescriber about your progress; never stop on your own.

9

Evidence & safety

What the research shows

Health agencies agree on the weekly amount of aerobic activity and on using effort to judge intensity. Large cohort studies link higher cardiorespiratory fitness with lower death and heart-disease risk, and a Cochrane review shows exercise-based cardiac rehabilitation lowers heart attacks in people with coronary disease. Interval training looks promising in several groups but the trials were short. Supplements and herbs have little or weak evidence for building fitness.

Limits of the evidence

  • Much of the evidence linking fitness and activity to lower risk is observational, so it shows association rather than proof of cause.
  • Trials of interval training were short (about 8 weeks to a few months) and some were in supervised settings.
  • Supplement studies were small and in healthy volunteers.
  • No sources read for this page gave specific diet or drink advice for building fitness.

Precautions and interactions

  • Check with a doctor before starting if you have been inactive or have a health condition.
  • Stop and seek help for chest pain, severe breathlessness, dizziness or faintness.
  • Ask a pharmacist about supplements and herbs if you take any medicine.
  • Never stop or change a prescribed medicine because you have started exercising.

Life-stage considerations

  • Pregnancy and postpartum: WHO 2020 guidelines include specific recommendations; discuss activity with your midwife or doctor.
  • Children and teenagers: need different amounts (about 60 minutes a day of moderate to vigorous activity per WHO); this page is for adults.
  • Older adults: benefit from activity, with balance work helpful; start gradually and get advice if you have conditions.

Warning signs

  • Chest pain that feels tight or squeezing, which may spread to the arm, neck or jaw (the NHS says to call 999 in the UK).
  • Severe difficulty breathing, or breathlessness that is sudden or getting worse.
  • Fainting, severe dizziness or a racing or irregular heartbeat.
  • Face drooping, weakness in one arm or slurred speech (stroke signs; the NHS says to call 999).
  • Pain during activity that does not ease when you stop.

Claim checks

Exercise reverses or cures heart disease

No source read supports this. Exercise lowers risk and cardiac rehabilitation reduces heart attacks, but neither is described as a cure.

9

You must do high-intensity workouts to get fit

Not needed. Guidelines accept moderate or vigorous minutes, and moderate activity counts.

5,14,6

Interval training is safe for everyone

Not for everyone. It was safe in a supervised trial in stable coronary disease, but needs caution without medical advice.

10,16,20

Beetroot juice will make you fitter

Limited evidence: helps some short tests, not a substitute for training.

18

More exercise is always better

Partly true: benefit rises with activity but levels off.

11,16

Questions people ask

How much exercise do I need for cardiovascular fitness?

The NHS and CDC say at least 150 minutes of moderate or 75 minutes of vigorous activity a week for adults, and the WHO suggests 150 to 300 minutes of moderate or 75 to 150 of vigorous, or an equivalent mix.

What counts as moderate and vigorous?

Moderate: you can talk but not sing. Vigorous: you can only say a few words before pausing for breath. The CDC also gives a 0 to 10 effort scale with moderate at about 5 or 6 and vigorous at 7 or 8.

Do short sessions count?

Yes. The CDC suggests breaking activity into smaller chunks and says some activity is better than none.

Is interval training better than steady exercise?

In a meta-analysis of people with cardiometabolic conditions it raised fitness more, and in a cardiac rehabilitation trial it did so too under supervision. In overweight adults the body-composition results were similar, with intervals taking less time. It suits some people but is not required.

Is it safe to start if I have not exercised for years?

Most people can build up gradually, but the NHS advises seeing your GP first if you have not exercised in a while or have a condition, and MedlinePlus advises starting slowly.

What if I have heart disease?

Ask your heart team about cardiac rehabilitation, which a Cochrane review found reduces heart attacks and hospital admissions. Do not begin hard exercise alone.

Which warning signs mean I should stop?

Pain, extreme breathlessness or dizziness. Chest pain that is tight or squeezing needs an emergency call; the NHS says 999 in the UK.

Does sitting still matter if I exercise?

The NHS says long sitting is harmful even if you meet your target. A pooled analysis found high activity levels (about 60 to 75 minutes a day) seemed to offset the extra risk from sitting, though not fully for heavy TV watching.

Can supplements improve my fitness?

Beetroot juice has some evidence for time to exhaustion in short tests. No evidence for other supplements or herbs building fitness was found for this page, and several can interact with medicines.

Is there such a thing as too much exercise?

A pooled analysis found no excess mortality risk at 10 or more times the minimum, but an American Heart Association statement notes very large volumes may be linked to some cardiac changes. Most people are far from that range.

References

  1. CDC. Measuring Physical Activity Intensity. Read 2026-10-31. source
  2. Kodama S, et al. Cardiorespiratory fitness as a quantitative predictor of all-cause mortality and cardiovascular events in healthy men and women: a meta-analysis. JAMA. 2009. PMID 19454641. source
  3. Ross R, et al. Importance of Assessing Cardiorespiratory Fitness in Clinical Practice: A Case for Fitness as a Clinical Vital Sign: A Scientific Statement From the American Heart Association. Circulation. 2016. PMID 27881567. source
  4. MedlinePlus. Exercise and Physical Fitness. Read 2026-10-31. source
  5. NHS. Physical activity guidelines for adults aged 19 to 64. Read 2026-10-31. source
  6. Bull FC, et al. World Health Organization 2020 guidelines on physical activity and sedentary behaviour. Br J Sports Med. 2020. PMID 33239350. source
  7. Ekelund U, et al. Does physical activity attenuate, or even eliminate, the detrimental association of sitting time with mortality? A harmonised meta-analysis of data from more than 1 million men and women. Lancet. 2016. PMID 27475271. source
  8. NHS. Exercise health benefits. Read 2026-10-31. source
  9. Dibben G, et al. Exercise-based cardiac rehabilitation for coronary heart disease. Cochrane Database Syst Rev. 2021. PMID 34741536. source
  10. McGregor G, et al. High-intensity interval training in cardiac rehabilitation: a multi-centre randomized controlled trial. Eur J Prev Cardiol. 2023. PMID 36753063. source
  11. Arem H, et al. Leisure time physical activity and mortality: a detailed pooled analysis of the dose-response relationship. JAMA Intern Med. 2015. PMID 25844730. source
  12. CDC. Physical Activity Guidelines for Adults. Read 2026-10-31. source
  13. NHLBI. Physical Activity and Your Heart. Read 2026-10-31. source
  14. Weston KS, et al. High-intensity interval training in patients with lifestyle-induced cardiometabolic disease: a systematic review and meta-analysis. Br J Sports Med. 2014. PMID 24144531. source
  15. Wewege M, et al. The effects of high-intensity interval training vs. moderate-intensity continuous training on body composition in overweight and obese adults: a systematic review and meta-analysis. Obes Rev. 2017. PMID 28401638. source
  16. Franklin BA, et al. Exercise-Related Acute Cardiovascular Events and Potential Deleterious Adaptations Following Long-Term Exercise Training: Placing the Risks Into Perspective-An Update: A Scientific Statement From the American Heart Association. Circulation. 2020. PMID 32100573. source
  17. Mandsager K, et al. Association of Cardiorespiratory Fitness With Long-term Mortality Among Adults Undergoing Exercise Treadmill Testing. JAMA Netw Open. 2018. PMID 30646252. source
  18. Hoon MW, et al. The effect of nitrate supplementation on exercise performance in healthy individuals: a systematic review and meta-analysis. Int J Sport Nutr Exerc Metab. 2013. PMID 23580439. source
  19. NHS. Heart attack. Read 2026-10-31. source
  20. NHS. Stroke symptoms. Read 2026-10-31. source

Related on AlternativeMed

Related goals

Build Heart-Healthy Habits → Support Healthy Blood Pressure → Improve Your Cholesterol Levels → Manage High Triglycerides → Support Healthy Circulation → Sit Less & Move More → Eat for Heart Health → Improve Your Everyday Stamina →

Ingredients, foods and supplements

Coenzyme Q10 → Hawthorn → Arjuna → Magnesium → Potassium →

Research, safety and claim-check resources

Activity, strength and muscle → Recovery after exercise → Everyday energy habits → Eating patterns compared → Healthy weight basics → Men's everyday health habits →