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Tempology - The Science of Tempo

Rep range, intensity, sets, volume, rest period, exercise selection, stability drivers* and length-tension curve manipulators*; Some of the most commonly manipulated training variables. But what about Tempo? Having taught for one of the largest UK training providers for about years, it always surprised me how little attention the variables of ‘tempo’ and ‘time under tension’ received on the resistance training theory sessions.

Indeed as I teach our Advanced Resistance Training CPD course, it seems that a large number of Advanced Instructors and Personal Trainers give it very little consideration during programming, and even less consideration as a tool of progression. Just think about it yourself for a moment… A PT client or one of your gym users comes up to you and says: ‘What can you tell me about Tempo and Time Under Tension?’ What would be your reply? A muttered response about ‘always under control’ or ‘two up, two down’? Think about it… how much could you really tell them? Because it is not given the attention it deserves on our NVQ and VRQ courses, this training variable is ignored and many instructors fail to fully comprehend its potential. Imagine never progressing or varying the rep range for a client, how much would that impede their long-term progression towards their goals?

So let me outline some of the key factors and considerations in relation to Tempo and its intrinsically linked partner - Time Under Tension.

Tempo can be defined as the speed of movement for an exercise. Many strength coaches will say that tempo is one of the training variables, if not THE training variable, that is most neglected for variation within a periodised programme (King, 2000; Poliquin, 2004). In fact variation in the tempo may be critical for prolonged strength development (Bührle and Schmidtbleicher, 1981), particularly for elite athletes in power sports.

Where some trainers may describe the desired tempo for their selected exercise in very basic terms (slow, moderate, fast…), this is simply insufficient for a modern professional in the health and fitness industry. There are a few different methods for showing the tempo; the following is the most comprehensive:

Example - Front Squat | 3 Sets | 6-8 Reps | 4.1.1.0 | 120s

This four digit code is used to describe the tempo for the different phases of a resistance exercise; Eccentric, Isometric, Concentric, Isometric. No matter whether the exercise is executed with a concentric or eccentric phase first, it is always written as Eccentric. Isometric. Concentric. Isometric. Using the example of the front squat, a client would undertake the following tempo:

• 4 seconds for the eccentric phase (the controlling phase from the standing position to the bottom position)


• 1 second for the isometric phase (the pause in the bottom position)


• 1 second for the concentric phase (the exerting phase from the bottom position to the standing position)


• 0 seconds for the isometric phase (the pause in the standing position)

Using this example each repetition would take a total of 6 seconds to complete, which becomes very important when calculating the Time Under Tension for a set. If a trainer wishes to have their client undertake a phase as fast as possible (normally the concentric phase) then an X can be used.

The speed of the movement determines a number of things, including the amount of tension developed, the use of mechanical energy (such as the stretch-shortening cycle), and the load (King, 2000). This obviously has implications for the outcome of the training effect; utilising the mechanical properties of the stretch shortening cycle will elicit more neurological adaptations (for Relative Strength and Power), whilst increasing the muscular tension can elicit more morphological changes (for Hypertrophy).

The term ‘Time Under Tension’ has been used by Ian King for decades and describes how long a muscle or group of muscles is under contractile stress. Time Under Tension, or TUT, is calculated by multiplying the number of repetitions by the tempo or total time for each repetition. For example, if 6 reps of the front squat are performed at a tempo of 4.1.1.0, then the total TUT for that set would be 6 x 6s, or 36 seconds.

The following table describes the training effect elicited from different times under tension (adapted from King, 2000):

It is critical to know the total Time Under Tension for a set, or the desired training effect may not be achieved. For example a young bodybuilder who races through his 10 reps on the squat, at an estimated tempo of 1.0.1.0, will only take about 20 seconds to complete the set. They believe that they are at an ideal rep range for hypertrophy, but because of the tempo used will elicit more relative strength gains.

Considerations with Tempo and Time Under Tension

• The desired training effect should dictate the total time under tension


• Selection of the eccentric tempo will vary depending on the desired training effect. For preparation and hypertrophy training, the usually range is between 3-6 seconds for the eccentric phase. For functional and relative strength 1-3 seconds is used.


• The eccentric duration will also be affected by the range of the exercise, for example it is easier and safer to undertake a 1 second eccentric lowering on a wrist flexor exercise than a front squat with a larger range of motion.


• The Olympic lifts and similar exercises will demand a fast eccentric phase


• If more muscular tension is desired for hypertrophying effects, then the mid-isometric pause should be increased to reduce the effect of the stretch shortening cycle. Research shows that this should be up to 4 seconds to eliminate the elastic energy from the eccentric phase (Wilson et al, 1991).


• For strength training the mid-isometric pause should be between 0-2 seconds and should be 0 seconds for power training.


• The majority of training should be done with concentric tempos of 1 second or less.


• There is a strong argument for inclusion of intra-set pauses in a bio-mechanically advantageous position for the recruitment of fast twitch fibres. These can be up to 10-15 seconds in duration, such as in Cluster Training.


• Variations of tempo can be achieved with chains or bands, which will increase the concentric time under tension.
  
  

* - Stability Drivers would include equipment such as Stability Balls, BOSU, Wobble Boards and Stability Discs. Length-tension curve manipulators would include chains or bands attached to Barbells or Dumbbells.

References

Bührle, M. and Schmidtbleicher, D. (1981). Kompo-. nenten der Maximal- und Schnellkraft. Sportwissenschaft 11:11–27. 6.

King, I. (2000). Speed of Movement. http://www.ptonthenet.com/displayarticle.aspx?ArticleID=1022

Poliquin, C. (2004). PICP Theory Manual Level 1. Poliquin Performance Centre.

Wilson, G.J., Elliott, B.C. and Wood, G.A. (1991). The Effect on Performance of Imposing a Delay During a Stretch-Shorten Cycle Movement. Medicine & Science in Sports & Exercise. 23(3): 364-370.

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