Vasthoudfase

Vasthoudfase, or the holding phase, is a term used in Dutch exercise science to describe the portion of a muscular contraction where the muscle length remains constant while force is produced. This is an isometric phase, occurring at a fixed joint angle and without movement at the joint. The concept is applied in both training and rehabilitation to target static strength, joint stability, and neuromuscular control.

In training, vasthoudfase is often incorporated into tempo prescriptions. During a repetition, an exercise may involve an eccentric lowering, a vasthoudfase held at a specific angle, and a subsequent concentric lifting. Common examples include planks, wall sits, overhead holds, and held contractions at a sticking point in a curl or press. The intensity is driven by the duration of the hold and, when applicable, the amount of external load.

Physiological effects of the holding phase include high muscle tension with minimal length change, resulting in different metabolic and neural responses compared with dynamic contractions. Benefits can include improved static strength, enhanced joint stability, tendon stiffness, and better neuromuscular coordination. Prolonged holds increase time under tension and can contribute to hypertrophic stimuli through metabolic stress, particularly when combined with progressive overload or added load.

Safety and progression considerations are important. Maintain proper technique and controlled breathing; avoid notable Valsalva maneuvers in susceptible individuals. Start with shorter holds and gradually increase duration or load. In rehabilitation or clinical contexts, vasthoudfase can target specific ranges of motion and is often integrated under professional guidance.