Is there a way for Apple watch to notify me of heart rate above 120 bpm WHILE exercising?

Greetings FroggieFit,

That's a wonderful question! Currently high and low heart rate notifications don't occur when utilizing a workout in the Workout application. You can learn more about heart health notifications via the following link and utilize the steps below to a adjust the heart rate notification settings.

1. "On your iPhone, open the Apple Watch app.
2. Tap the My Watch tab, then tap Heart.
3. Tap High Heart Rate, then choose a BPM. 
4. Tap Low Heart Rate, then choose a BPM."

Heart health notifications on your Apple Watch

Apple appreciates all feedback regarding their products, services, and features. If you would like to provide this feedback for Apple to review, you can do so via the Product Feedback website.

Take care!

Yes you can. On watchOS 9, When you set up the workout metrics, make sure to include heart rate zones. The new heart rate zones have a feature where you can set up alerts that are based on BPM.