The Heart Lab
Experiment with your heart science
Lab 1
Heartbeat Simulator
68BPM
Illustrative value for “Rest”
Rest
Sitting calmly. Your muscles need relatively little oxygen, so your heart can beat slowly. Resting rates vary widely between healthy people.
Simulated, illustrative values and a stylized trace — not your heart rate, not a diagnostic ECG, and not a target for anyone.
Lab 2
Blood Flow Explorer
Moving dots show the direction of flow. Red = oxygen-rich, blue = oxygen-poor (real blood is always red).
Body → heart
Oxygen-poorOxygen-poor blood returns from the body through the superior and inferior vena cava.
Lab 3
Exercise and Your Heart
Lab 4
Heart Rate Recovery Explorer
- End of exercise
- 162
- Drop at 1 min
- 44
- At end
- 75
All values are simulated beats per minute from a simple teaching model.
What does recovery mean?
When you stop exercising, your nervous system shifts back toward “rest and digest,” and heart rate falls — quickly at first, then more gradually. Harder efforts usually take longer to settle. Heat, hydration, sleep, illness, and fitness all affect recovery.
This simulator can't assess you
Lab 5
Myth vs. Fact
0 of 8 cards flipped
Sources
- National Heart, Lung, and Blood Institute (NIH): How the Heart Works — How the Heart Beats(opens in a new tab)
- Centers for Disease Control and Prevention: How to Measure Physical Activity Intensity(opens in a new tab)
- National Heart, Lung, and Blood Institute (NIH): How the Heart Works — How Blood Flows through the Heart(opens in a new tab)
- American Heart Association: All About Heart Rate (Pulse)(opens in a new tab)
Clinical review: pendingUpdated 2026-10-25