For clients with hypertension, NASM recommends low-intensity core stabilization exercises that avoid excessive isometric contractions of large muscle groups, avoid heavy loading, and maintain controlled breathing to prevent excessive blood pressure spikes. The prone isometric abdominal exercise (commonly known as a forearm plank) activates deep core stabilizers, such as the transversus abdominis and multifidus, without requiring high spinal loads or large dynamic movements. The Study Guide emphasizes that
"stabilizers... contract isometrically to stabilize the trunk and joints as the body moves" and that core stabilization should be prioritized before progressing to more dynamic exercises. The other options, like two- leg floor bridge or marching, can be useful for core activation but may involve more hip movement and higher intra-abdominal pressure. Standing cobra is a postural endurance exercise for the upper back and shoulders, not specifically a primary core stabilization drill. The prone isometric abdominal exercise thus fits both the physiological safety needs for hypertension and NASM's progression model.