What physiological effect does the Anti-G straining maneuver aim to mitigate?

The Anti-G straining maneuver is specifically designed to counteract the loss of consciousness that can occur during high G-force situations, which often leads to a phenomenon known as G-induced loss of vision (GLOC). When pilots experience high gravitational forces, blood can pool in the lower extremities, reducing cerebral perfusion and potentially resulting in a temporary loss of consciousness and visual acuity. This maneuver involves tensing the body, particularly the legs and abdominal muscles, along with controlled breathing techniques to maintain blood circulation to the brain, thus helping to prevent these dangerous effects.

Other physiological effects like increased heart rate, hypoxia due to altitude, and muscle fatigue are not the primary focus of the Anti-G straining maneuver. Although increased heart rate may occur as a secondary effect during high G forces, the maneuver itself is centered on maintaining consciousness and visual capability, making the correct choice clearly focused on managing the risks associated with G-induced loss of vision.