Electrical charges occurring during the cardiac cycle can be monitored from the surface of the body in a recording called an electrocardiogram (ECG/EKG in short). A normal ECG recording associated with a single cardiac cycle contains three distinctive waveforms. The P wave is generated when the atria depolarize as the action potential wave spreads out from the sinoatrial node. The QRS complex (which consists of the Q, R, and S waves) is triggered by the depolarization of the ventricles just before ventricular systole. The last waveform, the T wave, is triggered by the repolarization of the ventricles at the end of ventricular systole.
An ECG recording can be used to measure a number of different important intervals, namely the duration of the P-R interval, duration of the R-T interval, duration of the T-R interval, duration of a single heart beat, blood conduction time. However, what we will be measuring in this experiment Is the duration of a single cardiac cycle. It is the measurement from the peak of one R wave of the QRS complex to the peak of the next R wave. Using this value, the heart rate (bpm) can be calculated by dividing 60 by the cardiac cycle duration.
Heart Rate =
OR
Heart Rate =
Unit of Heart Rate = bpm (beats per minute)
Relation of Exercise to Heart Rate
Different types of activities, in this case exercises, affect the heart rate of a human differently. In this case, badminton and weightlifting go into two different categories of activities. Badminton is an aerobic activity, and weightlifting is an anaerobic activity. The difference between aerobic and anaerobic activity and the effect it has on the human heart rate will be outlined below:
- Aerobic Activity
Aerobic means "with oxygen." Aerobic exercise and activities are characterized by a slightly elevated heart rate that allows you to sustain the activities for long periods. During aerobic activities, your heart rate is increased to provide for the additional oxygen required, but it is not so high as to not be maintainable.
- Anaerobic Activity
Anaerobic means "without oxygen." Anaerobic exercise usually consists of high-intensity activities including sprinting and weight lifting. During these activities your body cannot provide enough oxygen to account for normal aerobic respiration. Your heart rate elevates to near maximum levels, attempting to pump more oxygenated blood, but it cannot keep up.
Variables
Independent
- The type of exercise (badminton or weightlifting) compared to stationary position
- The effect of exercises on the heart rate when compared to stationary position will be investigated
-
There is no applicable unit for this variable, but subject will be asked to do the activity constantly for 30 minutes before attaching the electrocardiogram sensor to him
- The way to control and measure it is by using a stopwatch
- The different exercises used are badminton and weightlifting. Stationary position will also be recorded.
Dependent
- Heart rate of the subject
- This variable is to be affected by the independent variable, which is type of exercise
- It will be measured using the Pasco Data sensor in electrocardiogram
Control
- The intensity of exercise should be closely monitored in order to produce accurate measurements. Although there are no feasible ways to measure intensity of exercise except to attach a heart rate monitor on subject, this variable should be taken into serious consideration. It is not viable to attach a heart rate monitor on subject in this experiment’s case because then it will defy the whole point of the electrocardiogram because we will already know the subject’s average heart rate even before EKG measurements.
- The person conducting the 3 independent variables must be the same. The person cannot change because different people have different initial heart rates, depending on their physiological fitness and healthiness of cardiovascular system. Therefore, the same person must be used to do all 3 activities in order to accurately portray the effects of different exercise on the heart rate of a person compared to stationary position.
- Other exterior stimuli such as abrupt noise and movement should be prevented in order to keep the results accurate.
Procedure
Apparatus:
- A laptop with Data Studio software on it
- PASCO: PASPORT EKG Sensor – PS-2111
- PASCO: EKG Sensor Electrode Patches
- Badminton Racket
- Weightlifting apparatuses
Method:
- Set up the Data Studio program on laptop.
- To measure the subject’s stationary heart rate, prepare subject for experiment by attaching adhesive electrode patches clipped with the EKG leads according to the following diagram:
- Press START on Data Studio program on the laptop to start recording the subject’s voltage and heart rate.
- Record subject’s voltage and heart rate for 30 seconds, then press STOP.
- Repeat these steps after subject conducts 30 minutes of badminton and weightlifting.
Note: These activities should be conducted with an interval of at least 24 hours apart from each other to avoid the previous activity interfering with the results of the next activity.
Flowchart
DATA COLLECTION AND PROCESSING
Raw Data Table
Data Processing and Calculations
Stationary Run #1
Stationary Run #2
Stationary Run #3
Badminton Run #1
Badminton Run #2
Badminton Run #3
Weightlifting Run #1
Weightlifting Run #2
Weightlifting Run #3
Processed Data Table
CONCLUSION AND EVALUATION