What type of exercise involves generating tension in a muscle without changing its length?

The correct answer is isometric exercise, which involves generating tension in a muscle without any change in its length. During isometric exercises, the muscle engages and contracts, creating force, but does not shorten or lengthen. This type of exercise is effective for improving muscle strength and endurance, as it allows for targeting specific muscles through static holds, where the joint angle remains constant.

Isometric exercises are also beneficial for maintaining muscle strength during periods of inactivity, as they can be performed without equipment and in various positions. Examples include planks and wall sits, where the muscles are activated but the overall joint position does not change. This contrasts with other types of exercises like isotonic and dynamic exercises, where movement and change in muscle length occur. Static stretching, while beneficial for flexibility, does not involve the active tension generation characteristic of isometric contractions.