"Time under tension" is a concept commonly used in the realm of fitness and bodybuilding. It refers to the amount of time a muscle or muscle group is actively engaged and under stress during an exercise. The idea behind this concept is that by increasing the duration that a muscle is under tension; you can potentially stimulate more muscle growth and strength development.
In practical terms, time under tension is manipulated by adjusting the tempo of your repetitions during an exercise. This involves controlling the speed at which you perform both the eccentric (lengthening) and concentric (shortening) phases of a repetition. For example, in a typical bicep curl:
Eccentric Phase: The lowering of the weight (e.g., when lowering the dumbbell during a bicep curl).
Isometric Phase: The pause at the midpoint where there's no movement.
Concentric Phase: The lifting of the weight (e.g., when curling the dumbbell up during a bicep curl).
By slowing down the lowering (eccentric) phase, pausing at certain points, and then also slowing down the lifting (concentric) phase, you increase the time your muscles spend under tension. This can be achieved by using a consistent count or rhythm for each phase, for example, a 3-second eccentric, 1-second pause, and 3-second concentric phase. This would result in a 7-second repetition, maximizing the time your muscles are working during that specific repetition.
Different tempos can be used based on your fitness goals. Slower tempos emphasize muscle tension, endurance, and muscle growth, while faster tempos might be more suitable for building power and explosiveness.
It's important to note that while time under tension can be a valuable tool in your training arsenal, it's just one of many factors that contribute to muscle growth and strength development. Varying your training approaches and focusing on proper form, progressive overload, nutrition, and adequate recovery are all essential components of a well-rounded fitness program. Always consult with a fitness professional or healthcare provider before making significant changes to your exercise routine.