Final answer:
Calisthenics exercises can be both isometric, involving muscle tension without joint movement, and isotonic, involving muscle contractions with joint movement. Isometric exercises, like holding a plank, do not change the angle of joints, whereas isotonic exercises, such as bicep curls, involve movement. The correct option is b.
Step-by-step explanation:
Calisthenics can include both isometric and isotonic exercises through the utilization of body weight. An isometric contraction occurs when the muscle produces tension without changing the angle of a skeletal joint, such as holding a plank position.
In contrast, isotonic exercises involve the movement of a joint during muscle contraction, like when the biceps contract to lift an arm in a bicep curl.
When the biceps contract and become shorter, this motion produces a bending at the elbow joint, lifting the forearm towards the shoulder, which is an isotonic action. If the triceps were to then contract, it would extend the arm, moving the forearm away from the shoulder.
Physical exercise involves both anabolic processes, such as muscle building, and catabolic processes, like glucose breakdown for energy during a workout. This balance is necessary for effective exercise results and overall health. The correct option is b.