Time under tension in exercise refers to the duration a muscle is actively contracting during a specific set of repetitions. This includes both the lengthening (eccentric) and shortening (concentric) phases of a lift, essentially the total time a muscle is working, as defined by the reference.
Understanding Time Under Tension (TUT)
Here's a breakdown of what time under tension involves:
- Concentric Phase: This is when the muscle shortens while lifting weight. Example: the bicep muscle shortening during the upward curl of a dumbbell.
- Eccentric Phase: This is when the muscle lengthens under tension while resisting the load. Example: the bicep muscle lengthening as you lower the dumbbell back down in a controlled manner.
- Total Time Under Tension: The combined time of the eccentric and concentric portions of each repetition. This is simply the amount of time a muscle is under tension during a workout as stated in the reference.
Why is TUT Important?
Controlling time under tension provides a method to increase the intensity of a workout without necessarily lifting more weight. This can be beneficial for various fitness goals:
- Muscle Growth: By increasing time under tension, you can stimulate muscle growth through increased metabolic stress and muscle damage, which are crucial for hypertrophy (muscle growth).
- Strength Gains: While it’s not the primary factor for strength gains (high load, low rep schemes take precedence), TUT can enhance muscular endurance and capacity, indirectly contributing to strength.
- Endurance: Longer periods of time under tension are more suited to building muscular endurance.
- Injury Prevention: Controlling the eccentric (lowering) portion of the movement, which contributes to TUT, is often crucial for injury prevention.
How to Control Time Under Tension
You can manipulate TUT through a number of ways:
- Tempo: Slowing down the speed of each phase of a lift is the most common method to increase TUT. For example, performing a squat with a 2-second eccentric and 2-second concentric will result in more TUT compared to a standard pace.
- Pause Reps: Pausing at the bottom, or top, of a movement can increase time under tension.
- Rep Range: Higher repetition schemes will naturally increase the total time under tension in a set.
Time Under Tension Table
| Phase | Description | Effect on TUT |
|---|---|---|
| Concentric | Muscle shortens while lifting the load | Contributes to total TUT |
| Eccentric | Muscle lengthens while resisting the load | Contributes to total TUT |
| Pause | Briefly holding the weight at a certain point (top or bottom) during a repetition | Increases total TUT |
| Slower Tempo | Performing reps at a slower pace | Increases total TUT |
| Higher Reps | Performing more repetitions per set | Increases total TUT |
Practical Application
For example, when performing a bicep curl, instead of a rapid lift, one might perform the curl using a 2-second concentric phase (lifting the weight) and a 3-second eccentric phase (lowering the weight). This control increases the total time under tension for the working biceps.
