There are many strength loading parameters that you can manipulate to achieve your desired goal, be it exercise selection, angle, reps, sets, and rest period. However, one parameter that is least manipulated or effectively utilised in any training system is that of tempo.
There are more than a dozen principles associated with tempo and time under tension (TUT), which this article alone could not cover, as it would turn into an essay. However it is important to understand the basic principle of tempo to effectively utilise it in your training.
Tempo Explained
Tempo has previously been written using a sequence, a three digit system and is now more commonly seen as a four digit system, representing the time it takes to complete a single repetition.
An example tempo may look like this 4-0-1-0
The first number in the sequence (4) represents the eccentric lowering, when you lower the resistance, e.g. descending in the squat, or bring the bar to your chest in a bench press. This is when the muscle is being stretched, resulting in an eccentric contraction where the muscle is being lengthened.
The second number in the sequence (0) denotes a time of pause in the stretched position. This pause usually occurs between the eccentric phase and the concentric (lifting) phase. In the above example there is no pause, however if we look at a 3-1-1-0 tempo during a bench press, the ‘1’ would refer to a 1 second pause when the bar makes contact with the chest.
The third number in the sequence (1) is the concentric contraction or lifting of the weight e.g. ascending out of the squat or pressing the bar at arms length in the bench press. During this action the muscle is being shortened. If an ‘X’ represents this portion of the lift it denotes moving the weight in an explosive manner.
The fourth number in the sequence (0) represents a time of pause in the contracted position, e.g. the top of a triceps extension or top position of a chin up. In the above 4-0-1-0 example there would be no pause at the top before going into the next repetition
Taking a look at a chin up and a tempo of 3-2-1-1, would mean 3 seconds to lower yourself to arms length, followed by a 2 second pause in the stretched position, taking 1 second to raise yourself to the bar, and pausing for 1 second at the top.
Time Under Tension
When the goal is fat loss or hypertrophy research support the principle of 40-70 seconds, which states that a muscle be loaded within that time frame to optimise the response i.e. a high release of human growth hormone (HGH). If strength is the goal the duration of a set should be between 20-40 seconds, this will enable you to recruit higher threshold motor units, which use high energy phosphagens as a source of fuel.
Furthermore longer time under tension especially during the eccentric phase promotes motor learning for improved technique and helps strengthen tendons.
Time Under Tension for Strength and Related Energy System and Fuel Source
Time Under Tension Energy System Fuel 1 - 10 seconds Anaerobic Alactic Power ATP-CP
11 - 20 seconds Anaaerobic Alactic Capacity CP
21 - 40 seconds Anaerobic Lactic Power Glycogen
41 - 120 seconds Anaerobic Lactic Capacity Glycogen
As a rule of thumb the length of the eccentric contraction is proportionate to the range of motion of the exercise, meaning the longer the range of movement, the longer the eccentric tempo, this will enable you to control the weight whilst maintaining efficient technique and correct bar path, reducing the potential for injury. Therefore, exercises such as squats, deadlifts, chin ups and presses should have a slower eccentric contraction.
There you have it a brief introduction to tempo and time under tension, add this important system into your training for a few weeks, yes you will not be lifting the same weight as before but I guarantee you your muscles will have worked harder, their capacity for work will have increased, and in the long term you will be lean, more athletic and stronger as a result.
If you are interested in any of the other principles associated with time under tension, send me a message and I will be happy to go into more detail in a future article.