When the ventricles of the heart contract, blood is forced into the arteries. The arteries are elastic and muscular—they expand to receive the blood, then contract to push it forward. This expansion and contraction creates a wave that travels through the arteries. This wave can be felt where arteries lie close to the skin, such as at the wrist or neck.

Materials Needed

• Stopwatch or wristwatch
• A partner
• Notebook and pen/pencil

Procedure

1. Locate the pulse: Place the fingers (index, middle, and ring) of your right hand on your left wrist, just below the base of the thumb. You should feel a throbbing sensation. Alternatively, you can feel the pulse at the side of your neck.

2. Count the beats: Use the stopwatch to count the number of pulses you feel in one minute. Record this number.

3. Repeat for accuracy: Repeat step 2 two more times. Then calculate the average of the three readings. This average is your pulse rate.

4. Test after exercise: Do some physical exercise, such as jumping or running in place for about 30 seconds. Immediately after exercising, repeat steps 1, 2, and 3 to measure your pulse rate again.

5. Record and compare: Write down both your resting pulse rate and your post-exercise pulse rate. Compare them.

Example Results Table

• Resting pulse rate is measured when the body is calm. It reflects the heart's basic activity level.
• Post-exercise pulse rate is higher because the body needs more oxygen and nutrients during physical activity. The heart pumps faster to meet this increased demand.
• The difference between the two readings shows how quickly your heart responds to the body's need for more blood.

• Physical activity: Exercise increases pulse rate.
• Emotions: Stress, anxiety, or excitement can raise the pulse rate.
• Health conditions: Fever, illness, or heart problems can change the pulse rate.
• Age: Babies have faster heart rates (about 70–190 beats per minute) than adults.

• Use the tips of your fingers, not your thumb (your thumb has its own pulse that may confuse the count).
• Ensure the stopwatch is started exactly when you begin counting.
• Do not press too hard on the artery, as this can block blood flow and affect the reading.
• Measure at the same location each time for consistent results.

In Tanzania, understanding pulse rate is useful for monitoring health during physical labour on farms, such as harvesting maize in Morogoro or keeping track of fitness while playing football. A student learning to measure pulse rate can use this skill to check their own health or help a family member monitor conditions like high blood pressure, which is common in adults. Simple tools like a phone stopwatch or a basic wristwatch are enough to carry out this experiment anywhere, making it a practical skill for everyday life in rural and urban Tanzania alike.