While hiking in the mountains in alaska, pete encountered a giant grizzly bear. he immediately felt his heart rate increase, his breathing become rapid, and sweat drip down his back. these events were most likely due to effects of the neurotransmitter called

Adrenaline

Explanation:

Adrenaline, also called norepinephrine, is a hormone produced mainly by the adrenal glands (medulla). Its main goal is to prepare the body to “fight or flight” response, it means that under stressful situations (in this case, fear), it triggers heart rate increase, airway expansion (to benefit gas exchange), blood pressure increase, mydriasis, etc.

Adrenaline release is stimulated by the sympathetic nervous system.

take a break move to stretching and slowly work back into physically exercising if the problem continues go to a doctor or physical therapist