What is ‘time under tension’ training anyway?
In short, it is a term commonly used in strength, conditioning, and bodybuilding and refers to how long a muscle is under strain during a set. Tempo is a variable referencing the speed of movement for an exercise. Tension can be created by doing bodyweight exercises such as push-ups and pull-ups, or traditional weight-lifting moves like bench presses and lat pull-downs. In both scenarios, you contract muscles against a resistive load and create mechanical tension.
Slow it down
Time under tension includes making mindful movements and focusing on motor control. One way to increase your time under tension is to vary the tempo during the different phases of muscle action.
According to ACE, There are three distinct phases of muscle action:
The muscle actively shortens when under tension. For example, the quadriceps shorten in the upward phase of a leg extension.
The muscle actively lengthens under tension or returns to its resting position from a shortened position. For example, the biceps brachii lengthen in the lowering phase of a biceps curl as it returns the arm to the starting position.
There is no visible change in length as the muscle contracts. A plank is an example of many of the major muscle groups performing isometric contractions.
How does it work?
Muscle tension created through resistance training stimulates the growth of new muscle proteins and can lead to gains. According to ACE, muscles that are exposed to that tension long enough can build up various metabolites (e.g., lactate, hydrogen ion, inorganic phosphate, and creatine) and it is this process that creates metabolic stress in muscle tissue triggering hypertrophic growth. In other words, muscles must experience a load that they are not used to, and they must experience that load for a certain duration.
Progressive load vs. Time under tension
Successful weight training should, of course, include progressive loads, meaning you challenge yourself with increasing the weight load.
But, adding a design element of controlled tempo can be critical for creating the desired stimulus for increasing muscle definition or size.
On your next weightlifting or body-weight exercise session, mix in some tempo changes to create additional time under tension in each phase of your muscle action.
Here is an example:
10 – 1/1 pushups, meaning 1 count up, 1 count down.
10 – 2/2 pushups, meaning 2 counts up, 2 counts down.
10 – 4/4 pushups, meaning 4 counts down, 2 counts up.