Question

Under what conditions does the heart rate change?

Answer 1

There are many conditions that makes someone's heart rate change. Below are a few.

1. The person does some physical activities
2. Someone stops doing physical activities
3. Someone is nervous can cause it to change.

I hope these help. Sorry if I misunderstood the question

Answer 2

Physical activities
Emotions: (fight or flight mentality) nerves, even thinking of someone you like, fear, ect.