In this activity, learners discover how their heart rate changes in different situations. Learners measure their baseline heart rates and compare them to their heart rates after completing various physical challenges and cardiovascular activities. Learners record this data on a table and plot it on a graph. This lesson plan includes questions to ask learners, online resources, and black-line masters. This is a good introductory activity to physical health, or a good activity for students to practice data collection and analysis.