Cardiovascular Response to Exercise

3-OTB Group 5Puentespina. Pusing. Razalan. Recio.

Treadmill Stethoscope Sphygmomanometer Timer

Materials

There were 8 representatives for the whole class in the experiment to conduct the experiment. From the 8 subjects two group was formed, one for athletic group and the other is for the non-athletic gr. Sixteen students monitored the vital sign of the subjects. Two was assigned to monitor the blood pressure, another two for the pulse rate and last two for recording the vital signs. Four athletic and non-athletic subjects were randomly assigned to the different assigned regimen. In a regimen there was one athletic and non-athletic subject performed the exercise that was assigned. For Regimen A, there was a 5 mins of warm up, 10mins of treadmill at 5-7mph ad 5 mins of cool down. For Regime B, there was no warm up, 10 mins of treadmill ant 5-7mph. For Regimen C, there was a 5 mins of warm up, 10 mins of 5-7mph, and no cool down. For regimen D, there was no warm up, 10mins of treadmill at 5-7mph and no cool down.

Procedure

Human error in monitoring and recording the data/improper technique

Improper pacing during warming-up and cooling down

Inability of the subjects to keep cycling above 100 revolutions per minute (rpm)

Self-proclaimed athletes.

Possible Errors

At Rest After 5 min After 1 min of exercise

After 5 min of exercise

After 10 min of exercise

After 5 min At Rest0

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40

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120

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180

200

Athletic AAthletic BAthletic CAthletic D

Athlete’s Heart Rates

At Rest After 5 min After 1 min of exercise

After 5 min of exercise

After 10 min of exercise

After 5 min At Rest0

20

40

60

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180

Non - Athletic ANon - Athletic BNon - Athletic CNon - Athletic D

Non – Athlete’s Heart Rates

At Rest After 5 min After 1 min of Exercise

After 5 min of Exercise

After 10 min of Exercise

After 5 min At Rest0

20

40

60

80

100

120

140

160

180

Systole ASystole NADiastole ADiastole NA

Blood Pressure – Regimen A

At Rest After 5 min After 1 min of Exercise

After 5 min of Exercise

After 10 min of Exercise

After 5 min At Rest0

20

40

60

80

100

120

140

160

Systole ASystole NADiastole ADiastole NA

Blood Pressure – Regimen B

At Rest After 5 min After 1 min of Exercise

After 5 min of Exercise

After 10 min of Exercise

After 5 min At Rest0

50

100

150

200

250

Systole ASystole NADiastole ADiastole NA

Blood Pressure – Regimen C

At Rest After 5 min After 1 min of Exercise

After 5 min of Exercise

After 10 min of Exercise

After 5 min At Rest0

20

40

60

80

100

120

140

160

180

Systole ASystole NADiastole ADiastole NA

Blood Pressure – Regimen D

DISCUSSION

THE CARDIOVASCULAR

SYSTEM

Aerobic exercise- OXYGENSYSTEMS: These are the heart, vascular (blood vessels) and respiratory systems.

Cardiovascular and respiratory systems

The heart is a double pump – two separate pumps that work side by side

The right side pumps deoxygenated blood to the lungs

The left side pumps oxygenated blood to the rest of the body

The Heart

The heart consists of four chambers –two upper atria and two lower ventricles

The atrio- ventricular valves separate the atria and ventricles

The semi-lunar valves are found in the pulmonary artery and aorta.

THE HEART

STROKE VOLUME- volume of blood ejected from the heart when the ventricles contract (at rest = 70 cm3)

HEART RATE – the number of (ventricle) contractions in one minute (at rest = 72bpm)

STROKE VOLUME – (Q) volume of blood ejected from the heart in one minute (at rest = 5Litres)

Q = HR X SV

Heart definitions

Resting Heart Rate Anticipatory Rise Rapid Increase of Heart Rate Continued but slower increase of Heart Rate Slight Fall/ Steady Plateau Continued rise in HR Rapid fall in HR Slower Fall in HR toward resting levels

The Heart During Exercise

There are three main groups of blood vessels. Arteries and arterioles- transport oxygenated

blood away from the heart. Capillaries – bring blood to the tissues where

oxygen and carbon dioxide are exchanged. Veins and venules – transport deoxygenated

blood back towards the heart.

Blood vessels

Blood vessels have three layers except capillaries which are single walled.

Arteries and arterioles have middle layer of smooth muscle which allows them to vasodilate (widen) and vasoconstrict (narrow).

Arterioles have precapillary sphincters at the entry to the capillary. These control blood flow.

Blood vessel structure

Capillaries are one cell thick to allow efficient gaseous exchange.

Venules and veins have thinner muscular walls. The can vasodilate and vasoconstrict. They also have valves to prevent the backflow of blood.

BLOOD VESSEL STRUCTURE

Starlings Law of the Heart states that stroke volume is dependent on venous return.

At rest the amount of blood returning to the heart (venous return) is enough to supply the demands of the body.

On exercise this is not enough so venous return must be increased. This happens in the following ways.

Venous return

Controlled by Vasomotor Control Center – Medulla Oblongata

Redistribution of Blood Skeletal Muscles, Organs, Skin, Brain Vasodilate – Skeletal Muscles Vasoconstrict - organs

Vascular Shunt

Primary indicator of the functional capacity of the circulation to meet the demands of physical activity

Cardiac Output = Heart rate x Stroke Volume

Cardiac Output

At Rest◦ Individual Variation◦ On average, entire blood volume of approx. 5

liters is pumped from the left ventricle each minute

◦ Aforementioned value is similar for both trained and untrained subjects

Cardiac Output

Untrained◦ 5 liter cardiac output◦ 70 beats per minute (average)◦ 71ml per beat◦ Stroke volumes for females usually average 25%

below male values and are 50 to 70 ml per beat at rest

◦ “Gender difference” due to average body size

Cardiac Output

Endurance Athletes◦ Sinus node under greater influence of

acetylcholine◦ Normally about 40-50 beats per minute at rest◦ 5 liters per minute, 100ml per beat

Cardiac Output

Endurance Athletes◦ Endurance Training increases vagal tone that

slows heart◦ Heart muscle strengthened through training is

capable of a more forceful stroke with each contraction

Cardiac Output

During exercise◦ Blood flow increases in proportion to intensity of

the exercise◦ Cardiac output has a rapid increase until a

plateau is reached Sedentary – 20-22L/min, 195bpm Endurance – 35-40L/min, <195bpm

Cardiac Output

Training effects◦ Larger stroke volume during rest and exercise

compared to untrained◦ Greatest increase in stroke volume occurs in

transition from rest to moderate exercise◦ Max. stroke volume is reached at 40-50% of the

max. oxygen consumption, usually represents heart rate of 110-120bpm

◦ For athletes, small inc. in stroke vol. in transition from rest to exercise with major inc. in cardiac output (stroke vol. 50-60% above resting values)

Stroke Volume in Exercise

Blood flow to specific tissue is generally proportional to their metabolic activity

Blood Flow

At Rest◦ 5 L cardiac output is distributed and one-fifth of

cardiac output is distributed to muscle tissue whereas major portion goes to other organs.

◦ 4-7ml/min of blood for every 100g of muscle

Blood Flow

During Exercise◦ Major portion of cardiac output is diverted to

working muscles.◦ 50-75ml per 100g of muscle tissue

Blood Flow

Redistribution of Blood◦ Blood is redistributed and directed through

working muscles from areas that can temporarily tolerate a reduction in normal blood flow. Shunting of blood from specific tissues occurs primarily during maximum exercise.

Blood Flow

“The Athlete’s Heart” Fundamental biologic adaptation of muscle

to an increased workload. Individual myofibrils thicken Number of contractile filaments within the

muscle fiber increases

Cardiac Hypertrophy

Exercise Physiology

Used to measure the work capacity of an individual

Represents the maximum oxygen consumption

The total aerobic capacity provides a measure of increasing metabolic work of peripheral skeletal muscle.

Aerobic Capacity

Relationship between oxygen consumption and intensity of work being done

Oxygen

consumption

workload

Increases with work Increases primarily through an increase in

ventricular rate 2 determinants of cardiac output

-heart rate -stroke volume

Cardiac Output

Relationship between cardiac output and oxygen consumption

Cardiac output

Oxygen consumption

Limited with persons age Decrease in maximum HR with age. Estimated by: 220-(age in years)

Heart Rate

Relationship between heart rate and oxygen consumption

Oxygen consumption

Heart rate

Age determined maximum

Represents the quantity of blood with each heartbeat.

Major determinant is diastolic filling volume which is inversely related to the Heartrate.

Stoke volume

Oxygen consumption

Stroke volume

The actual oxygen consumption of the heart Limited in anginal threshold.

-anginal threshold is defined as the point where the myocardial oxygen demand exceeds the ability of the coronary circulation to meet the demand. anginal chest pain

Myocardial Oxygen Consumption

Myocardia; oxygen

demand

Oxygen consumption

Myocardia; oxygen

demand

Oxygen consumption

Myocardia; oxygen

demand UE

LE

Oxygen consumption

supine

Upright

Gender Differences in Sports and Exercise

Women are more likely to report themselves as exercising more than men if asked who exercises more (Strelan & Hargreaves, 2005).

Women are traditionally viewed as more concerned about their appearance (Thompson, Heinberg, Altabe, & Tantleff-Dunn, 1999).

Research says…

Men are less likely than women to exercise for appearance related reasons (Tiggemann & Williamson, 2000).

Women attempt to meet sociocultural expectations of the thin ideal, through exercise (Strelan & Hargreaves, 2005).

Research says…

Performance differences between men and women likely result from biological differences as well as social and cultural restrictions placed on females during development

Historically, fewer women have competed in athletic events than men.

Biological vs. Social Differences

Major differences between boys and girls do not occur until puberty.

Puberty in girls—estrogen causes pelvis broadening, breast development, fat deposition in hips and thighs, increased bone growth, and faster closure of growth plates

Puberty in boys—testosterone causes increased bone formation and muscle mass

Body Size and Composition

Testosterone leads to– Bone formation, larger bones– Protein synthesis, larger muscles– EPO secretion, red blood cell production

Estrogen leads to– Fat deposition (lipoprotein lipase)◦ Faster, more brief bone growth◦ Shorter stature, lower total body mass– Fat mass, percent body fat

Body Size and Composition

After puberty, girls’ average relative body fat is about 10% greater than boys.

Men not only have more muscle mass, but also carry a higher percentage of their muscle mass in the upper body compared to women

Body Size and Composition

Innate qualities of muscle and motor control are similar

For the same amount of muscle, strength is similar

Muscle fiber cross-sectional areas are smaller and muscle mass is less in women

Strength Differences

More muscle mass is proportionately distributed below the waist in women

Upper-body strength expressed relative to body weight or fat-free mass is less in women (but differences between genders are less)

Strength Differences

WOMEN have Higher HR response at rest and for same absolute levels of submaximal exercise (about the same Q as men)

Same HRmax but lower Qmax in WOMEN because of lower SVmax

WOMEN have Lower SV at rest and at all exercise intensities due to smaller heart size and smaller BV

WOMEN have Less potential for increasing a-vO2 diff because of lower arterial O2 content

Cardiovascular Responses

WOMEN: Differences in response compared to men are mostly due to smaller body size

WOMEN have Higher respiratory rate at given ventilatory rate

WOMEN have Smaller tidal volume at given ventilatory rate

WOMEN have Smaller ventilatory volume during maximal exercise due to smaller lungs

Resulting in lower maximal pulmonary ventilation

Respiratory Responses

Muscle strength differs between sexes◦ Upper body: women 40 to 60% weaker◦ Lower body: women 25 to 30% weaker◦ Due to total muscle mass difference, not

difference in innate muscle mechanisms

No sex strength disparity when expressed per unit of muscle cross-sectional area

Physiological Responses to Acute Exercise

Causes of upper-body strength disparity◦ Women have more muscle mass in lower body◦ Women utilize lower body strength more

Research indicates women more fatigue resistant

Physiological Responses to Acute Exercise

Cardiovascular function differs greatly

For same absolute submaximal workload◦ Same cardiac output◦ Women: lower stroke volume, higher HR

(compensatory)◦ Smaller hearts, lower blood volume

For same relative submaximal workload◦ Women: HR slightly , SV , cardiac output ◦ Leads to O2 consumption

Physiological Responses to Acute Exercise

Sex differences in respiratory function◦ Due to difference in lung volume, body size◦ Similar breathing frequency at same relative

workload◦ Women frequency at same absolute workload

Physiological Responses to Acute Exercise

Body composition changes◦ Same in men and women– Total body mass, fat mass, percent body fat– FFM (more with strength vs. endurance

training)

Weight-bearing exercise maintains bone mineral density

Connective tissue injury not related to sex

Physiological Adaptations to Exercise Training

Strength gains in women versus men◦ Less hypertrophy in women versus men, though

some studies show similar gains with training◦ Neural mechanisms more important for women

Physiological Adaptations to Exercise Training

Men outperform women by all objective standards of competition◦ Most noticeable in upper-body events

Women’s performance drastically improved over last 30 to 40 years◦ Leveling off now◦ Due to harder training

Sport Performance

Females Males

Innate qualities of muscle and motor control Same Same

Strength Same, for same amount of muscle Same, for same amount of muscle

Muscle fiber in cross sectional areas Smaller Larger

Muscle mass More muscle mass in lower body More muscle mass in upper body

Fat free mass < >

Heart rate at rest ↑ ↓

Maximum heart rate Same Same

Cardiac output Same Same

Maximum cardiac output ↓ ↑

Maximum stroke volume ↓ ↑

Heart size smaller larger

Body size smaller larger

Respiratory rate ↑ ↓

Tidal volume smaller Larger

Ventilator volume Smaller Larger

Lungs size Smaller Larger

SUMMARY

Special concerns for women

No reliable data indicate altered athletic performance across menstrual phases

No physiological differences in exercise responses across menstrual phases

World records set by women during every menstrual phase

Menstruation

Seen more in lean-physique sportsEumenorrhea: normalOligomenorrhea: irregularAmenorrhea (primary, secondary): absentCan affect 5 to 66% of athletes

***Menstrual dysfunction ≠ infertility

Menstrual Dysfunction

Pregnancy

Warm Up and Cool Down

Allows body to adjust to the cardiovascular demands of exercise.

Increase blood supply in skeletal muscles. Must have 5-10 min. of warm up before

actual exercise.

Warm Up

a.) increasing blood flow to active skeletal muscles

b.) increasing blood flow to the myocardiumc.) increasing the dissociation of

oxyhemoglobind.) it leads to earlier sweating thus regulates

the temperature e.) in reducing the incidence of abnormal

heart rhythms in heart conduction

Benefits of Warm Up

a.) increase in blood flow which brings more oxygen to working muscles

b.) an increase in temperature which produces 1.) an increase in the rate transport of enzymes needed for the energy systems 2.) a decrease in the viscosity of the

blood which improves blood flow3.) an increase in oxygen dissociating

from oxyhaemoglobinc.) delays the onset of blood lactic acid

Cardiovascular Changes

gradual increase in muscle temperature and peripheral blood flow

energy metabolism and increased tissue elasticity

improve neuromuscular function maintain acid-base balance reduce oxygen deficit during vigorous

exercise it reduces risk of neuromuscular injuries

Benefits

Follows after exercise prevents venous pooling thus reducing the

risks of fainting keeps respiratory and muscle pumps

working which prevents blood pooling in the veins and maintains venous return

capillaries remain dilated

COOL DOWN

prevention of post exercise hypotension and dizziness

promotes more rapid removal of lactic acid facilitates heat dissipation reduces the risk for ventricular

dysrhythmias (patients with heart disease) cardiac death are reduced

Benefits

This experiment is focus on the cardiovascular system’s response to exercise. From the experiment, it is evident that the heart of the athletic participant is much stronger than that of the other. Referring to the heart rates of both participants, the non-athletic subject shows a far higher heart rate as compared to the athlete and this on the other hand is due to the lack of training but with respect to both subjects, there have been gradual increases and decreases of the heart rates due to the phases of warming-up and cooling-down, respectively. Gender differences is a factor in sports and exercise though of lower significance. Females have smaller heart, lung and body (in general) compared to men but he maximum heart rate, the innate qualities of muscle and motor control are the same for both genders.

CONCLUSION

Plowman, S., Smith, D.(2008). Exercise Physiology for health fitness and performance. Philadelphia. Lippincott Wilkins & Wolter Kluwer business.

  Robergs, Robert. (1997).Exercise Physiology

Exercise Performance and clinical application. United States of America. Von Hoffman Press Inc.

  Power, S., & Howley, E.(2009).Exercise Physiology

Theory and Application to fitness and Performance. New York. McGraw-Hill Companies Inc.

 

References