R graph gallery is a great resource for this. I would recommend trying the [histogram][1] and [boxplots][2] for starters. I think it would also be great to see visualizations that they can draw conclusions from:
- data stratified by gender and then by different biometrics (for instance, by gender and heartbeat) to look at how it differs among the two groups. What does this tell you about the different gender?
- divide the population based on heartbeat before exercise (low/high heartbeats or any other groups) then compare them to how their heartbeat/breath is after exercise.What does this tell you about the children with different biometrics? What is higher and lower heartbeat associated with?
Bonus: If you use R, then the code is also linked and easy to follow through. [1]: https://www.r-graph-gallery.com/histogram/ [2]: https://www.r-graph-gallery.com/boxplot/