aerobic exercise

What are the main cardiorespiratory benefits of aerobic training?

Higher VO₂max; lower submaximal HR, BP, ventilation and myocardial oxygen demand.

What central and peripheral changes improve VO₂max?

Central: higher maximal cardiac output. Peripheral: improved capillarisation and oxygen extraction.

How does aerobic training change skeletal-muscle capillary density?

It increases capillary density and improves oxygen delivery.

How does aerobic training affect resting blood pressure?

It generally reduces resting systolic and diastolic blood pressure.

How does aerobic training affect HDL and triglycerides?

It often raises HDL cholesterol and lowers triglycerides.

How does regular aerobic activity affect adiposity?

It can reduce total body fat and visceral (intra-abdominal) fat.

How does aerobic exercise change glucose regulation?

Improves insulin sensitivity and glucose tolerance; may reduce insulin requirements.

What six variables describe acute and chronic aerobic exercise responses?

Heart rate, stroke volume, cardiac output, blood pressure, blood flow and ventilation/VO₂.

Why does heart rate rise just before and at exercise onset?

Parasympathetic withdrawal and increased sympathetic stimulation.

What is the approximate HR increase per MET during incremental exercise?

About 10 beats/min per MET (rough guide; varies across people).

How are HR and VO₂ related in moderate incremental exercise?

They rise approximately linearly together over much of the submaximal range.

What chiefly determines age-predicted maximal heart rate?

Age; formulas are rough estimates with substantial individual variation.

How does resting HR change after aerobic training?

It generally decreases.

Why does resting HR fall with endurance training?

Increased vagal tone, reduced sympathetic drive and higher resting stroke volume.

What intrinsic pacemaker change can contribute to athlete bradycardia?

A lower intrinsic sinoatrial-node firing rate.

How does HR at a fixed submaximal workload change after training?

It decreases, often more noticeably at higher submaximal workloads.

How does HRmax change with endurance training?

Usually little change; it may decrease slightly.

What does a slower-than-expected HR recovery suggest?

Potential autonomic/cardiovascular concern; interpret using test protocol and clinical context.

What benchmark is often used for first-minute HR recovery?

A drop of about 12 bpm or more, depending on the recovery protocol; not a universal cutoff.

What cardiac structural adaptations occur with endurance training?

Physiological LV enlargement/hypertrophy, possible RV dilation and atrial enlargement.

What functional cardiac adaptations support endurance performance?

Better diastolic filling, stronger contraction and higher maximal stroke volume.

Define stroke volume (SV).

Volume of blood ejected by one ventricle per heartbeat.

Name three principal determinants of stroke volume.

Preload (filling), myocardial contractility and afterload.

What is preload?

Ventricular wall stretch near end-diastole, linked to venous return and end-diastolic volume.

What is afterload?

Pressure/resistance the ventricle must overcome to eject blood.

State the Frank–Starling mechanism.

Within physiological limits, greater end-diastolic filling/stretch produces stronger contraction.

Why does venous return help increase stroke volume during exercise?

Greater ventricular filling increases preload and contraction through Frank–Starling.

When does stroke volume increase most during incremental exercise?

During the transition from rest to moderate workloads; later response varies.

How does endurance training affect stroke volume at rest and exercise?

Generally increases SV at rest, submaximal exercise and maximal exercise.

How do untrained people compensate for lower SV during exercise?

They depend relatively more on increased HR to raise cardiac output.

What is the formula for cardiac output?

Q = HR × SV.

Calculate Q for HR 150 bpm and SV 100 mL/beat.

15,000 mL/min = 15 L/min.

What happens to cardiac output during incremental aerobic exercise?

It rises with intensity as heart rate and stroke volume increase.

How does Q respond during short, constant-load moderate exercise?

It usually approaches steady state within a few minutes.

What does cardiovascular steady state mean?

Oxygen transport approximately matches a stable exercise metabolic demand.

Why is maximal cardiac output higher after endurance training?

Mainly because maximal stroke volume increases.

Compare maximal Q and Q at a fixed submaximal workload after training.

Maximal Q rises; Q at a given absolute submaximal workload often changes little.

How can endurance-trained people achieve similar submaximal Q at lower HR?

Their higher stroke volume offsets their lower heart rate.

What happens to SBP during dynamic aerobic exercise?

It normally increases with rising exercise intensity and cardiac output.

What happens to DBP during dynamic aerobic exercise?

Usually stays similar or decreases slightly owing to lower peripheral resistance.

How does SBP respond during a prolonged constant-load session?

It rises initially then usually plateaus; it may drift with conditions.

How does heavy resistance exercise differ from aerobic exercise in BP response?

Can produce much larger transient SBP and DBP increases.

Why should breath-holding be avoided during heavy exercise?

Valsalva-like straining can greatly increase intrathoracic pressure and BP swings.

How may upper-limb resistance work affect BP versus leg work?

For comparable relative tasks, upper-limb exercise may provoke higher BP responses.

How does sustained endurance training generally affect BP?

Can lower resting BP, particularly in people with elevated baseline BP.

What chest symptom is abnormal during exercise?

Chest pain, pressure or tightness suggestive of angina; stop and assess.

Why should one fixed exercise BP limit not be applied to everyone?

Thresholds depend on setting, protocol, baseline BP and medical guidance.

What happens to arterioles in active skeletal muscle during exercise?

They dilate, increasing local blood delivery.

What happens to blood flow to many nonessential vascular beds during exercise?

Sympathetic vasoconstriction redirects a greater share of flow to working muscles.

How does the proportion of Q reaching skeletal muscle change with exercise intensity?

It markedly increases.

What happens to absolute cerebral blood flow in typical dynamic exercise?

It is relatively well maintained, despite shifts in percentage of total Q.

How does capillarisation change after endurance training?

The capillary-to-fibre ratio increases in trained muscles.

How does endothelial vasodilator function adapt to aerobic training?

Improves, partly through nitric-oxide-mediated dilation.

What long-term vascular structural change may occur with training?

Larger arterial diameter and improved vascular capacity.

Why does ventilation increase during aerobic exercise?

Higher oxygen demand and CO₂ production require increased gas exchange.

How does minute ventilation relate to tidal volume and breathing frequency?

Minute ventilation = tidal volume × respiratory rate.

What happens to tidal volume early in incremental aerobic exercise?

It rises substantially; it later tends to plateau.

How does respiratory rate behave near maximal exercise?

It continues rising after tidal volume starts to plateau.

What is end-expiratory lung volume (EELV) at rest?

Approximately equal to functional residual capacity (FRC).

How does EELV typically change from rest to moderate exercise?

It usually decreases as expiration encroaches on expiratory reserve volume.

What lung-volume reserves accommodate deeper exercise breathing?

Inspiratory reserve volume (IRV) and expiratory reserve volume (ERV).

What do VO₂ and VCO₂ mean?

VO₂ is oxygen uptake; VCO₂ is carbon dioxide output.

How does ventilation at a fixed submaximal workload often change with training?

It may be lower and more efficient, with deeper/slower breathing.

How can aerobic training reduce respiratory muscle work at a given workload?

Through a more economical breathing pattern and improved ventilatory efficiency.

In pulmonary gas exchange, where does O₂ diffuse?

From alveoli into pulmonary capillary blood.

In pulmonary gas exchange, where does CO₂ diffuse?

From pulmonary capillary blood into alveoli.

What should be reviewed before prescribing aerobic exercise?

Goals, screening, medical history, limitations and physical activity history.

What constraints shape an aerobic exercise plan?

Time, equipment, availability, setting and preferences.

What major priorities may drive aerobic exercise programming?

Health, general fitness or sport/performance.

What does training age mean?

The person’s prior experience and adaptation to structured training.

Why should aerobic modality resemble the target activity?

Training specificity improves transfer to the intended task.

Give three aerobic training modalities.

Walking/running, cycling and swimming (choose for ability and goals).

What are the major components of an aerobic prescription?

Frequency, intensity, time/duration, type, progression and monitoring.

Define continuous aerobic training.

Sustained exercise at a relatively steady submaximal intensity.

What aerobic intensity is cited for continuous training in these notes?

Often about 60–80% VO₂max; adapt to the person and context.

Define high-intensity interval training (HIIT).

Repeated hard exercise bouts separated by lower-intensity recovery intervals.

Define sprint interval training (SIT).

Repeated near-maximal or all-out sprint efforts separated by recovery.

List the nine key HIIT programming decisions.

Mode; work intensity/duration; rest intensity/duration; reps; sets; between-set time/intensity.

Name four ways to prescribe aerobic exercise intensity.

%VO₂max, %HRmax, RPE and %MAS (or work rate/power).

What is a MET?

A multiple of resting metabolic rate; conventionally 1 MET ≈ 3.5 mL O₂/kg/min.

What is MAS (or vVO₂max)?

Minimum running speed associated with attainment of VO₂max, measured or estimated.

What does RPE quantify?

An individual’s subjective rating of exercise effort.

What is the usual range on the Borg 6–20 RPE scale?

6 (no exertion) to 20 (maximal exertion).

What is a limitation of predicting HRmax as 220 − age?

It is a rough population estimate with wide individual error.

For age 70, what is HRmax from the 220 − age estimate?

150 bpm (approximate, not measured).

For estimated HRmax 150, what is 64–76% HRmax?

96–114 bpm (moderate band used in the notes).

For estimated HRmax 150, what is 77–95% HRmax?

About 116–143 bpm (vigorous band used in the notes).

Why must HIIT volume be controlled as intensity increases?

Higher-intensity sessions add fatigue and can elevate injury risk if poorly progressed.

What is anaerobic speed reserve (ASR)?

Maximum sprint speed minus maximal aerobic speed (MAS).

Why monitor high-speed efforts near maximal sprint speed?

They produce substantial fatigue and musculoskeletal loading.

How should rest usually change as work-interval intensity rises?

Increase recovery duration and/or lower recovery intensity.

What is a common starting HIIT work:rest ratio at 100–120% MAS?

About 1:1, modified to the session goal and individual.

What is a possible work:rest range for very fast sprint efforts?

About 1:2 to 1:6 or more; adequate recovery depends on goals.

How is session-RPE training load often calculated?

Session RPE × session duration (minutes) = arbitrary units (AU).

Calculate training load for RPE 14 lasting 30 minutes.

14 × 30 = 420 AU, using the stated RPE scale.

Calculate weekly load for three 10-minute sessions at RPE 12.

3 × (10 × 12) = 360 AU.

Which variables can be increased as a person adapts?

Frequency, duration and intensity; progress according to tolerance.

Is the 10%-per-week progression rule universal?

No. It is a heuristic, not a validated injury-proof ceiling.

Why include recovery or active-rest days?

To allow adaptation and help manage cumulative fatigue.

What should guide rate of progression?

Age, health status, functional capacity, response and current training load.