Cardiorespiratory EnduranceChapter 3

Cardiorespiratory System

The heartRight side pumps blood in the pulmonary circulationLeft side pumps blood in the systemic circulation

Blood pressureSystole—contractionDiastole—relaxation

Circulation in the Heart

Video: http://www.youtube.com/watch?v=D3ZDJgFDdk0

Circulation in the Heart

Right Atrium•Receives deoxygenated blood from vena cava•Pumps deoxygenated blood to right ventricle

Left Atrium•Receives oxygenated blood from pulmonary veins•Pumps oxygenated blood to left ventricle

Right Ventricle•Pumps deoxygenated blood to lungs for gas exchange via pulmonary arteries

Left Ventricle•Pumps oxygenated blood to the system (e.g., tissues and muscles) via aorta

Cardiorespiratory System

Blood vesselsArteries = vessels that carry blood away from the heartVeins = vessels that carry blood to the heartCapillaries = very small blood vessels that distribute blood to all parts of the body

Respiratory System

Alveoli = tiny air sacs in the lungs through whose walls gases such as oxygen and carbon dioxide diffuse in and out of the blood

Lungs expand and contract about 12–20 times a minute at rest

Monitoring Your Heart Rate

Carotid artery in the neck Radial artery in the wrist

Count beats for 10 seconds and multiply the result by 6 to get rate in beats per minute

Cardiorespiratory System

AT REST Heart rate: 50–90

beats/minute Breathing rate: 12–20

breaths/minute Blood pressure: 110/70 Cardiac output: 5

quarts/minute Blood distributed to

muscles: 15–20%

DURING EXERCISE Heart rate: 170–210

beats/minute Breathing rate: 40–60

breaths/minute Blood pressure: 175/65 Cardiac output: 20

quarts/minute Blood distributed to muscles:

85–90%

Energy Production

Metabolism—the sum of all chemical processes necessary to maintain the body

Energy from foodBroken down into glucoseStored as glycogen

ATP (adenosine triphosphate): The energy “currency” of cells

Three Energy Systems

Three Energy Systems

Oxygen Deficit/Oxygen Debt

EPOC = Excess post-exercise oxygen consumption

Benefits of Cardiorespiratory Endurance Exercise

Improved cardiorespiratory function Improved cellular metabolism Reduced risk of chronic disease

Cardiovascular diseaseCancerType 2 diabetesOsteoporosisDeaths from all causes

Cardiorespiratory Fitness and Risk of Death

Benefits of Cardiorespiratory Endurance Exercise

Better control of body fat Improved immune function Improved psychological and emotional

well-being

Effects of Cardiorespiratory Endurance

Assessing Cardiorespiratory Fitness

Field tests for maximal oxygen consumption:

The 1-mile walk testThe 3-minute step testThe 1.5-mile run-walk test

Developing a Cardiorespiratory Endurance Program

Setting goals Applying the FITT equation

FrequencyIntensityTimeType of activity

Frequency of Training

Train 3–5 days per week Beginners should start with 3 and work up

to 5 days per week Moderate physical activity such as

walking can be done daily

Intensity of Training Target heart rate zone

Estimate your maximum heart rate (MHR)220 – your age = MHR

Multiply your MHR by 65% and 90%People who are unfit should start at 55% of MHR

Example: 19-year-old MHR = 220 – 19 = 20165% training intensity = 0.65 X 201 = 131 bpm90% training intensity = 0.90 X 201 = 181 bpm

A subject’s pre-exercise heart rate is 65 beat per minute (bpm). After a 15-minute bout of cardiorespiratory exercise, the subject’s post-exercise heart rate is 173 bpm. The subject is 26 years of age. Find the following:

Problem Solving

The subject’s maximum targeted heart rate for cardiorespiratory training intensity?

220 – 26 = 194The subject’s percentage of cardiorespiratory training intensity?

173/194 = 89%

Intensity of Training Ratings of perceived exertion (RPE) Talk test

Time (Duration) of Training

Total of 20–60 minutes is recommended One single session or multiple sessions of

10 minutes or more Different intensity levels require different

durationsHigh-intensity activity = 20 minutes Low-to-moderate-intensity activity = 45–60 minutes

Warming Up and Cooling Down

Warming Up (5–10 minutes)Muscles work better when warmed upRedirect blood flow to working musclesSpread synovial fluid

Cooling down (5–10 minutes) Blood flow and respiration return to normal

Cardiorespiratory Endurance: FITT

Building Cardiorespiratory Fitness

Rate of improvement depends on age, health status, initial level of fitness, and motivation

Initial phase (1–4 weeks): 3–4 days per week, low end of target heart rate zone, 20–30 minutes

Improvement phase (2–6 months): 3–5 days per week, middle to upper end of target heart rate zone, 25–40 minutes

Maintaining Cardiorespiratory Fitness

Continue to exercise at the same intensity on 3 nonconsecutive days per week

If you have to stop, start the program again at a lower level

Cross-training maintains motivation

Hot Weather and Heat Stress

Dehydration = excessive loss of fluid Heat cramps = sudden development of muscle spasms

and pain Heat exhaustion = heat illness related to dehydration

from exertion in hot weather Heat stroke = a severe and often fatal heat illness

characterized by significantly elevated core body temperature

Heat Index

Source: National Weather Service

Above a core temperature of 103 degrees Fahrenheit: weakness, vomiting, headache. This is a medical emergency.

At about 104 degrees: heat stroke. Confusion, dehydration. Seizure possible. Above 105 degrees: delirium. If not treated immediately, internal organs will begin

to fail. Above 106 degrees: convulsions. Above 107 degrees: coma. Above 108 degrees: death.

Heat Illness

Preventing Heat Illness

Use caution in high heat or humidity (over 80°F and/or 60% humidity); lower your intensity and/or add rest breaksExercise morning or eveningDrink plenty of fluids; check weight before and after exerciseAvoid supplements and beverages containing stimulantsWear clothing that “breathes”Slow down or stop if you feel uncomfortable

Heat Stroke Deaths in Football 'All Preventable'

By Dan Peterson, LiveScience's Sports Columnist posted: 02 February 2009 08:29 am ET

Last Monday, first-year Kentucky high school football coach David Jason Stinson pleaded not guilty to charges of reckless homicide in the death of Max Gilpin, a 15-year-old offensive lineman. Gilpin collapsed Aug. 20 while running sprints with the team on a day when the heat index reached 94 degrees.

The case could signal a landmark shift in the expectation for how coaches deal with struggling players on a hot day.

Gilpin's body temperature was 107 degrees when he reached the hospital and he died three days later from heat stroke. The risks of heat-related diseases to athletes, both young and old, are always present but the warning signs are often hidden.

Since 1995, 33 football players have died from heat stroke, according to an annual report from the University of North Carolina. Frederick O. Mueller, professor of exercise and sports science at UNC and the author of the report, calls the figure unacceptable.

"There's no excuse for any number of heat stroke deaths, since they are all preventable with the proper precautions," Mueller said.

Exercise in Cold Weather

Hypothermia = low body temperature due to exposure to cold conditions

Frostbite = freezing of body tissues characterized by pallor (paleness), numbness, and a loss of cold sensation

Prevention:Don’t stay out in very cold temperatures (consult wind chill values)Wear appropriate clothing

Wind Chill

Source: National Weather Service

Poor Air Quality

Poor air quality can decrease exercise performance; it especially affects those with respiratory problems

Do not exercise outdoors during a smog alert or if air quality is poor

Air Quality Index

Exercise Injuries

Consult a physician for serious injuries and those that do not improve within a reasonable amount of time

Managing minor exercise injuries: RICE

RestIceCompressionElevation

You completed a mile run (four laps around a regulated track) in 18:34. Your post-exercise heart rate is 164 bpm. You are 22 years old.Find the following:

Problem Solving

The subject’s maximum targeted heart rate for cardiorespiratory training intensity?

220 – 22 = 198The subject’s percentage of cardiorespiratory training intensity?

164/198 = 83%

Wellness Worksheet Assignment

Connect Chapter 3 Worksheet due on Monday, September 24th, no

later than 11:59PM