EFFECTS OF EXERCISE ON HEART RATE AND BLOOD PRESSURE 1
Medical expertshave identified hypertension as a critical risk factor in theanalysis of cardiovascular disease mortality and morbidity. Existingevidence indicate that the both fatal and nonfatal cardiovasculardisease have a active relationship with blood pressure (Carter,Banister & Blaber, 2003). As such, higher levels of bloodpressure have a corresponding increase in the severity of nonfataland fatal cardiovascular diseases (Fletcher et. al., 1996). Thispaper discusses the effects of exercise on the heart rate and bloodpressure by incorporating a statistical analysis of the process.
Systolic and Diastolic Blood Pressure
The termssystolic and diastolic are used to indicate the blood pressurereadings. Systolic refers to the top number whereas diastolic is thelower number with regards to the blood pressure readings (Sesso et.al., 2000). It is a term coined from Greek word systole which means“a drawing together or a contraction.” When the heart beats, thecontraction pushes blood into the arteries to the rest of the body.The contraction of the heart results in systolic blood pressure. Anormal systolic blood pressure is deemed to be 120 and below. Readingbetween 120 and 139 refers to an average blood pressure that ishigher than the ideal and as such is known as borderline high bloodpressure (Sesso et. al., 2000). The importance of systolic bloodpressure measurement increases with an individual’s age. Systolicblood pressure is concerned with the left ventricles of the heart asit allows the contraction of the blood vessels.
The diastolicpressure number, on the other hand, refers to the bottom number whenthe heart relaxes and rests from beats. The term is coined from Greekword diastole which means drawing apart. Therefore, the diastolicnumber is 80 or less (Sesso et. al., 2000). However, a readingbetween 80 and 89 is considered average but higher than ideal.Diastolic is therefore the pressure exerted on the walls of thearteries in between heart beats as the body relaxes. This form ofblood pressure should be extensively monitored in young individuals.This type of blood pressure offers minimal pressure on the arteries,and the ventricles of the heart are filled with blood (Sesso et. al.,2000).
Mean Arterial Pressure (MAP)
The mean arterialpressure is a medical term that refers to an individual’s averageblood pressure. To achieve its objective, it uses the readings of asingle cardiac cycle (Sesso et. al., 2000). As blood is pumped intothe left ventricle of the heart, a certain amount of pressure isgenerated. To determine effectively the mean arterial pressure (MAP),various components are required. They include cardiac output (CO),organized vascular resistance (SVR), and the central venous pressure(CVP) (Sesso et. al., 2000). Therefore, the formula for determiningmean arterial pressure (MAP) is as follows
MAP= (CO x SCR) + CVP
Any changes ineither the cardiac output (CO) and systematic and vascular resistanceculminates in corresponding changes in mean arterial pressure (Sessoet. al., 2000). The MAP varies between a combination of diastolic andsystolic values. To achieve the most desirable results, equal weightis given to all the infinitesimal time intervals. It is, for thisreason, that means the arterial pressure is not equal to the simpleaverage of systolic and diastolic pressure (Sesso et. al., 2000).
The experiment serves to highlight the changes that are witnessed inthe heart rate and blood pressure when individuals engage inexercises.
How Exercise Influences the Heart Rate and Blood Pressure
The bloodpressure of an individual varies depending on the kind of activitythey are engaging. With regard to the flow of blood, researchindicates that when the body is at rest, only 20% of the circulatingblood within the body is directed at the skeletal muscle. During thisperiod, over 60% of blood in the body is directed towards the liver,kidneys and the brain (Sesso et. al., 2000). However, as the exercisecommences, blood flow is directed towards the working muscles of thebody. The amount of blood flow to the lungs increases massively as aresult of greater activity in the right ventricle (Sesso et. al.,2000). This is the section of the heart that pumps blood to otherparts of the body such as lungs (Carter, Banister & Blaber,2003).
Systolic bloodpressure increases in linear proportion to the intensity of theexercise. When more blood is being pumped from the heart, thepressure levels also increase substantially in the body organs thattransport the blood from the heart to other parts of the body.However, in most instances, there is minimal change concerning thediastolic pressure among individuals engaged in exercises (Sesso et.al., 2000). The higher the intensity of the exercise, the higher theheart rates will be, and the greater the subsequent increases insystolic blood pressure will be. The low-intensity aerobic exercisesare safest and, therefore, recommended to individuals withcardiovascular complications as well as those embarking on a newexercise regime. Regular exercise has been identified as one way oflowering the blood pressure (Fletcher et. al., 1996). This is becauseregular exercises make the heart stronger and as such it can pumpmore blood with less effort (Carter, Banister & Blaber, 2003).
To obtain thereadings necessary for analysis in the paper, individuals undertookan exercise with the primary objective of determining subsequentchanges to the heart rate and blood pressure. The procedure was asfollows:
1. The participants were required to sit down
2. A device that wraps around the wrist and configures Heart Rate(HR)and Blood Pressure (BP) readings is then used
3. The participants then conduct continuous step-ups on a 2-foot boxfor 3 minutes
4. After three minutes, post exercise HP and BP are then taken
The PreExerciseand PostExercise readings were obtained. The mean and 2SE forPreExercise heart rates were 77.0882 and 3.889 respectively. For thePostExercise reafings, the mean and 2SE were 104.529 and 9.5684respectively.
Figure 1: Heart Rate
For systolic pressure, the following readings were obtained. ThePreExercise mean and 2SE were 128.765 and 5.65 whereas thePostExercise mean and 2SE were 149.529 and 10.442 respectively.
Figure 2: Systolic Pressure
The diastolicblood pressure readings for PreExercise mean were 77.9118 and 2.6412for 2SE the PostExercise readings on the other hand were 82.3824 and2.485 for the mean and standard deviation respectively.
Figure 3: Diastolic Pressure
Based in the meanand standard errors obtained in the study, the 95% confidenceinterval (CI) for the PreExercise heart rate is 73.1992-80.9772whereas that of the PostExercise heart rate is 94.9606-114.0974.Since the two 95% CI do not overlap, it can be concluded that themean values are statistically different from one another.
The 95%confidence interval (CI) for PreExercise systolic pressure is123.115-134.415 whereas that of PostExercise systolic pressure is139.971-159.971. Based on the fact that the two 95% CIs do notoverlap, it can be concluded that the mean values are different fromone another.
The 95%confidence interval (CI) for PreExercise diastolic pressure is75.2706-80.553 and 79.8974-81.8974 for PostExercise diastolicpressure. Based on the values obtained, it can be concluded that thevalues overlap and as such, the mean values are statisticallyrelated.
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Fletcher, G. F., Balady, G., Blair, S. N., Blumenthal, J., Caspersen,C., Chaitman, B., … & Pollock, M. L. (1996). Statement onexercise: Benefits and recommendations for physical activity programsfor all Americans a statement for health professionals by thecommittee on exercise and cardiac rehabilitation of the council onclinical cardiology, American heart association. Circulation, 94(4),857-862
Sesso, H. D., Stampfer, M. J., Rosner, B., Hennekens, C. H., Gaziano,J. M., Manson, J. E., & Glynn, R. J. (2000). Systolic anddiastolic blood pressure, pulse pressure, and mean arterial pressureas predictors of cardiovascular disease risk inmen. Hypertension, 36(5), 801-807