Chapter 2
Cardiorespiratory Fitness
Alicia, 20 missed bus and had to jog to class. By the time she got there could hardly breathe (previous CC runner!). How did she get so out of shape?
Main Points/Topics:
- Aerobic activity
- Oxygen consumption
- Designing an aerobic program
- Principles
- Components
- The complete program
- Exercising in different environments
- Exercise and physical activity pyramid
Assumptions
*Aerobic activity affects fitness and Oxygen consumption
* Working tissues pull Oxygen from the
blood as needed.
I.Aerobic Activity
* Examples of Aerobic Activity…..
A.Aerobic: with oxygen; not the need to breathe during an activity but the add’l Ox needed in the muscle to perform the activity.
* CR Endurance: ability of the lungs, heart,+ bl vessels to deliver adequate amts of oxygen to the cells to meet the demands of prolonged activity.
Why is the supply, delivery, +utilization of Ox so important during Ex?
* ATP: (Adenosine Triphosphate)
A high energy chemical compound that provides the energy for muscular contraction. The body’s fuel for Ex.
* The body has only a small amt of stored ATP. The body can produce its own ATP when oxygen is available.
* Ox must be present in muscles to produce ATP through aerobic metabolism (AM)
* AM occurs in the mitochondria (power house) of cells to produce ATP
* Regular aerobic ex improves your ability to supply (lungs + CO) and utilize (A-VO2 difference) oxygen more efficiently. This enables you to produce more ATP…ex longer
B. Anaerobic Activity: without oxygen; activity that doesn’t require add’l Ox to be taken by the muscles to perform the activity. Shorter in duration.
* Examples….
III.Oxygen Consumption
* is determined by Ox supply, CO (SV x HR), and A-VO2 difference
* Aerobic activity is directly related to CR fitness because it affects oxygen consumption
* Resting HR is high or low? Y?
- VO2 max
the maximal amt of Ox the body is able to consume per minute of physical activity.
* best indicator of CR/aerobic fitness!
- Determining Ox consumption consider
Ox supply (lung functioning, at rest
shallow breathing vs deep breathing)
Cardiac Output amount of blood leaving the heart per minute. (SV x HR) Stroke volume: amount of blood pumped per beat; HR # of beats per minute.
Arterial-Venous Oxygen Difference (A-VO2 ): difference bw the Ox content in arterial and venous blood.
Bl leaves the heart in the arteries (high in Ox), working tissues take Ox from the blood and input CO2 in the bl, so the bl now lower in Ox and higher in waste products returns to the heart in the veins
* When resting…Breathing rate, HR, SV, use of Ox is low. You don’t need more Ox.
* When exercising..
BR inc; take in more Ox + expire CO2
HR x SV (CO) inc to supply more oxygen rich blood to working tissues
A-VO2 difference incr because working tissues extract and use more Ox from Bl
C.Reaching a steady state
(BR, HR, Ox cons): Overhead
*point at which the activity becomes truly aerobic…(AM supplying most of the ATP)
*prior to reaching a steady state, most ATP is supplied thru Anaerobic Metabolism (stored). Ease into it.
*after you stop ex BR, HR, Ox cons gradually return to resting levels..ease out of it. Help your body recover and redistribute blood.
D.Maintaining aerobic ex
If you commit to 15 weeks of training 3x’s per wk, 20-30 min sessions
* maximal Ox consumption (VO2 max) will increase
* improves lung function (supply), CO, A-VO2 diff (utilization)
* your body becomes more efficient at exercising. Build endurance!
IV.Designing an Aerobic Ex Program
A.Find your training zone (diff than book)
1. MHR: 220-age: 220-27 = 193
2. RHR:17 x 4 = 68
3. HRR:193 - 68 = 125
4. TI 40%125 x .4 + 68 = 118
50%125 x .5 + 68=130.5
60%-85%125 x .6 + 68 = 143- 125 x .85 + 68 = 174.25
B.Principles of an Ex Program
1.Overload: to improve a physiological system, you must stress or challenge the system beyond its normal limits…your body adjusts and requires more of a stimuli to achieve the same HR.
* varies among indivs/ not competitive
2.Specificity: your aerobic ex program must be specifically related to your overall ex objectives
* Ready for marathon or just want to be able to run to class w/out losing breath
3.Individuality: evaluate your fitness level/ ex goals on a personal level, not comparison.
* unique genetics, history of ex/fitness,
and motivation
4.Reversibility:getting in shape doesn’t ensure you’ll stay in shape…your body forgets… “exercise has little staying power”
* once you stop.. M str, M power, M end, speed, agility, flexibility, CR end all decrease
* tortoise vs the hare…a lifetime perspective. Commit to a program you can maintain.
C. Components of an Ex Program (FITT)
1.Frequency:how often
* beginners 3-5 (20-30 min) per wk
* weight loss 5-6 (45-60min) Low-Mod
* Maintenance: 3 (20-30 min) non-consecutive days
* most of the health-related benefits are short term (diminish after 2 wks, disappear w/in 2-8 months , ex as a (near) daily medication
2.Intensity:how hard a person has to ex to improve or maintain fitness
* Use your HR as a guide
* CR dev occurs b/w 40%-85% of HRR
*40-50% for unfit/older, 1st 6-8 wks
* @ 50% sign. health benefits (metabolic profile….more later)
* 60-85% opt CR training zone; increase VO2 max
* reevaluate RHR periodically.....Y?
* check pulse 5 min into workout 10 sec
after 15 sec HR will dec, adjust accordingly
* goals determine intensity
* Rating of Perceived Exertion (Borg) people’s subjective observations of their exercise efforts; Overhead
* 12 somewhat hard –16 hard
3.Duration (Time): how long you ex
* generally b/w 20-60 min
* consider I (physical activity vs ex)
* for opt results should be continuous but benefit from 3, 10 min sessions
* 5 min warm up (lower I)
* THR 20-50
* 5 min cool down (gradual dec)
4.Type (Mode): form of exercise
* any aerobic activity that will get and keep your heart to desired training zone.
* low impact vs high impact.....
(walking) (aerobics) injury risk
* as amt of muscle mass involved inc so does the dev of CR system (CC skiing)
V.The complete program: 5 parts
- Warming up – stretching
* 5-10 min; low intensity; similar mode
* incr body temp, HR, BR
* dec muscle/joint injuries and soreness
* help body transition to steady state
- CR endurance
* 20-30 min; exercise in target HRR
* beginning, health, fitness goals?
* specific mode is less important
3.Cool down - stretching
* 5-10 min; activities performed in WU
* best time to stretch/improve flexibility
* lowers the risk of joint/muscle injury
* help body redistribute blood and
prevent pooling
4.Flexibility Activities
* 5-10 min; The ability of a joint to move freely thru its full range of motion
- Strength Activities:
* 45 min; 2-3 times per week (full body)
VI.Exercising in different environments
- Heat: stresses the body and makes it
difficult to thermoregulate
Hyperthemia: too much heat; body is unable to dissipate heat.
* Older people are more susceptible
Things to consider prior to Ex:
radiant heat (sun light), humidity (amt of moisture in the air), heat conduction (physical contact between your body and another surface) heat convection (air movement across the body)
* take in fluids before and during ex
Heat related problems:
* heat cramps: cramps/spasms; stop, get out of heat, massage/stretch, rehydrate
* heat exhaustion: fainting/dizzy, profuse sweating, cold/clammy; same t(x) + remove excess clothing rub body with cold/wet towel
* heat stroke: serious disorientation, warm/dry skin, no sweating, emergency medical attention
- Cold: stresses the body, heat production
* Hypothermia: inability to maintain heat/core temperature
Mild 97-95, Mod 95-90 Severe <90
* mild symptoms include shivering, euphoria, disoriented…moderate similar symptoms but more severe
* consider wind and wetness as well as temperature
* dress in layers; easy to peel off
- Altitude:
Hypoxia: higher altitudes less Ox present
* work harder to achieve same product
* don’t have to work as hard to achieve THR…..why not?
* Symptoms incl headache, dizzy, rapid HR, can be life threatening
*Adjust gradually, PA should be shorter, less Intense
* Full acclimatization takes several weeks
V.Summary and Ex/PA pyramid
* Distinguish b/w health (foundation) and fitness (at the top) benefits..components incl body comp, CR and Muskuloskeletal fitness
* Health benefits can be experienced thru a variety of lifestyle related activities
- Ex pyramid (overhead) bottom to top
* 30 min of daily activity
* aerobic ex + flexibility 3-5 days per week
* strength training + recreational activity
2-3 days per week
* high intensity ex + competitive sports
requires proper preparation,