Certified Personal Trainer (NSCA) Practice Exam 2026 – Complete Prep Guide

The "fight or flight" response, also known as the acute stress response, is a physiological reaction that occurs in response to perceived harmful events, attacks, or threats to survival. During this response, the body undergoes several significant changes aimed at preparing for quick action.

The correct answer highlights several key physiological changes that occur during this response: increased heart rate, elevated blood pressure, enhanced blood flow to muscles, and the release of adrenaline (epinephrine) from the adrenal glands.

1. Increased heart rate allows for more blood to be pumped throughout the body, delivering oxygen and nutrients to vital organs and muscles. This is critical for enhancing physical performance and readiness.

2. Elevated blood pressure results from constriction of blood vessels, helping to redirect blood flow towards major muscle groups while simultaneously reducing it to areas that are less critical in a survival situation.

3. Enhanced blood flow to the muscles ensures that they are primed for action, providing strength and endurance necessary for either fighting or fleeing.

4. The release of adrenaline stimulates various organs and systems in the body, increasing energy availability and preparing the body to respond quickly and effectively to the threat.

In contrast, the other options present physiological changes that do not align with the fight or flight response