CARDIORESPIRATORY ENDURANCE
•The ability of the heart, blood vessels, blood and respiratory system to supply nutrients and oxygen to the muscles, and the ability of the muscles to utilize fuel to allow sustained exercise
•A person with good cardiorespiratory endurance can persist in physical activity for relatively long periods without undue stress
•Sometimes referred to as cardiovascular fitness, cardiovascular endurance, or aerobic fitness.
•The lab measure of this component of fitness is referred to as aerobic capacity
ACUTE AND CHRONIC CARDIOVASCULAR ADAPTATIONS
Acute (During Exercise):
•↑ heart rate (HR)
•↑ stroke volume and cardiac output
•↑ breathing rate and tidal volume
•Vasodilation to working muscles
•↑ oxygen extraction
PRESCRIBING INTENSITY
1. Heart Rate (HR)
•Most common method
•HRmax = 220 – age (estimate)
•Better method – Tanaka formula
•Max HR = 208 – (0.7 * age)
•Example for a 22-year-old
•Max HR = 208 – (0.7 * 22) = 193 bpm
•Target zones:
•Light: 50–60% HR max
•Moderate: 60–75% HR max
•Vigorous: 75–90% HR max
•Use heart rate monitors, smartwatches, or manual pulse
Why does it matter?
•Improves heart health
•Increases energy and endurance
•Reduces risk of chronic disease (CVD, Type 2 diabetes, obesity)
•Enhances mental health and mood
•Foundation for overall physical fitness
Continued... Chronic (With Consistent Training)
Chronic (With Consistent Training):
•↓ resting HR and BP
•↑ stroke volume and capillarization
•↑ VO₂ max (aerobic capacity)
•↑ mitochondrial and enzyme activity
•↑ efficiency in oxygen utilization
CHECK YOUR PULSE
Arteries have elastic walls that stretch.
When the heart beats, the surge of blood causes a pulse.
Guidelines to consider
Learn to locate quickly
10-second count * 6
15-second count * 4
Do not use the thumb to count
CARDIORESPIRATORY PHYSIOLOGY- THE HEART
4 chambers which pump and receive blood in a rhythmical fashion to maintain good circulation
1. Right Atrium - collects the oxygen-poor blood from the body and then drains the blood into the right ventricle
2. Right Ventricle - pumps blood low in oxygen to the lungs. The lungs then "refill" the blood with oxygen
3. Left Atrium - receives oxygenated blood from the lungs and pumps it to the left ventricle
4. Left Ventricle - pushes oxygenated blood into your aorta, from which the blood is pumped to the entire body
VO2 MAX/AEROBIC CAPACITY
•Maximum oxygen update (VO2 max) = how much oxygen a person can use in maximal exercise
•Elite endurance athletes can extract 5 or 6 L of oxygen per minute from the environment
•An average person typically extracts about 2-3 L of oxygen per minute
•VO2 max is typically adjusted for a person's body size, which can influence scores.
•Low-fitness individuals are 3-6 times more likely to develop symptoms of heart disease, metabolic syndrome, or diabetes than high-fitness individuals
HEART RATE ZONES
Zone / % of MHR
Zone 1 40% - 50% slow walk and talk
Zone 2 60% - 70% Feels power walk, easy jog
Zone 3 70% - 80% purposeful run, short phrases not conversation
Zone 4 80% - 90% big push, no talking
Zone 5 90% - 100% all out sprint stop and breath after 30 seconds or less
CARDIORESPIRATORY PHYSIOLOGY- THE HEART
carried on from previous
•Like other muscles in the body, the heart becomes stronger if it is exercised.
•When the size and strength of the heart increase, it can pump more blood with each beat.
•accomplishes the same amount of work with fewer beats.
•Typical resting heart rate (RHR) is around 70-80bpm, but highly trained endurance athletes can be closer to 30-50 bpm
TYPES OF AEROBIC TRAINING
1. Continuous Training
•Steady-state effort (e.g., jogging, cycling, swimming)
•Good for beginners and base building
2. Interval Training
•Alternating higher/lower intensities (e.g., 1 min fast, 1 min slow)
•Efficient and effective for improving VO₂ max
3. Circuit Training
•Combines resistance and aerobic movements in sequence (e.g., stations)
•Great for general fitness and time efficiency
4. Cross-Training
•Varying modalities to reduce overuse and boredom (e.g., swim, bike, row)
PRESCRIBING INTENSITY
2. RPE (Rating of Perceived Exertion)
•Borg scale: 6–20 or simplified 1–10 scale
•Moderate = ~3–5 on 10-point scale
•Correlates well with HR
3. Talk Test
•Moderate = can talk but not sing
•Vigorous = difficult to speak in full sentences
1. Path of blood flow through systematic and pulmonary circulation
1. Right Atrium - deoxygenated blood
2. Right Ventricle (right atrioventricular valve)
3. Pulmonary trunk and pulmonary arteries (pulmonary valve)
4. In pulmonary capillaries, blood loses CO2 and O2
5. Pulmonary veins (oxygenated blood)
6. Left Atrium (left atrioventricular valve)
7. Left ventricle (aortic valve)
8. Aorta and systemic arteries
9. In systemic capillaries, blood loses O2 and gains CO2
10. Superior vana cava, Inferior vana cava, and Coronary sinus
(Cycle continues)
APPLYING THE FITT PRINCIPLE TO CARDIO
•Frequency: 3–5 days/week
•Intensity: If maximal aerobic capacity is known, an appropriate intensity can be set as a percentage of the maximum level
•Heart rate reserve, max heart rate and RPE
•Moderate (50–70% HRmax) to vigorous (70–90%)
•Time: 20–60 minutes per session
•Type: Rhythmic, continuous, large-muscle group activities. e.g., biking, walking, running, rowing, sport matches, etc.
•Volume: Minimum of 150 minutes of moderate activity per week, 75 minutes of vigorous activity per week, or a combination of the 2
•20 – 30 min/day – very low fitness
•30 – 90 mins/day – good fitness
•30 – 90 mins/day – high performance
•Progression: Increase one variable at a time to avoid injury or burnout
PROGRAM DESIGN AND SAFETY CONSIDERATIONS
•Begin with a base phase (focus on frequency and duration)
•Progress gradually using 10% rule (no more than 10% increase per week)
•Include warm-up and cool-down in every session
•Consider environmental factors (covered in Chapter 3): heat, cold, air quality