Circulatory and respiratory systems – heart rate during activity
Integrated ScienceLife ProcessesAges 13–14
Use it with your class: students open it from a link or a QR code, with no account needed.
Next in Life Processes
The four-chambered heart contracts to pump blood through the pulmonary circuit (heart → lungs → heart) and the systemic circuit (heart → body → heart); the blood changes between bright red and dark red as gas exchange happens in the lungs and in body tissue. Choose an activity (sleep, rest, walk, run) to see heart rate, blood pressure, blood flow, breathing rate and tidal volume change, along with a real-time ECG trace and lungs inflating and deflating. The Exercise and recovery screen shows heart rate, cardiac output, aerobic and anaerobic respiration, lactate, oxygen debt (EPOC) and recovery time for a chosen intensity and duration; the Pulse practical measures the pulse over 15 s before and after exercise and records the results in a table.
Lesson: Blood and the circulatory system; The respiratory system
What it shows
Humans have a double circulation: the right side of the heart pumps blood to the lungs and the left side pumps oxygenated blood to the body. During exercise, heart rate and stroke volume rise, so cardiac output (heart rate × stroke volume) increases. When the oxygen supply cannot meet the muscles' demand, anaerobic respiration makes extra ATP and lactate builds up; after exercise the body keeps taking up extra oxygen (oxygen debt, EPOC). A fitter person has a lower resting heart rate and a shorter recovery time. The pulse practical compares counting by hand with a digital monitor.
How to use
In Circulation, press Sleep, Rest, Walk and Run and compare the readings. In Exercise and recovery, set the intensity, exercise time and resting heart rate, press Start exercise and watch heart rate, O₂ uptake and lactate; note the O₂ deficit, oxygen debt and recovery time. In Pulse practical, press Take pulse (15 s) at rest, then Exercise, then measure again straight away and after each Wait for the next minute.
Parameters you can change
- Activity Sleep, Rest, Walk, Run
- Resting heart rate 50–100 bpm
- Show blood flow in vessels
- Show respiration (lungs, breathing rate)
- Screen Circulation, Exercise and recovery, Pulse practical
- Exercise intensity 20–100 % of VO₂ max
- Exercise time 1–20 min
Questions to explore
- Why do both heart rate and breathing rate increase when a person starts running?
- In which organ does dark red, deoxygenated blood become bright red, oxygenated blood?
- Why does the pulmonary artery carry deoxygenated blood even though it is an artery?
