The amount of weight an athlete lifts in an exercise, relative to the 1 repetition maximum (1RM) for the same exercise, determines how much tension a muscle produces and the number of motor units recruited. These are two hugely important factors in strength development.
Unfortunately, there is a trade off between the intensity, and the overall volume that is feasible in a given workout. Which of these is prioritised (intensity or volume) at a particular stage of a performance plan, is decided primarily by the training objective.
In general, where relative strength is the quality most required by an athlete, the intensity will need to be greater than 85% of their 1RM, for the majority of their strength training. Intensities of this level and above result in increased strength through enhanced neural drive that is best developed through heavy lifting. When sufficient volume is accumulated, lifts in the 85-100% of 1RM best stimulate the development of the type 2b muscle fibers which are required for generating high levels of power and speed.
Where maximal hypertrophy gains are desired, intensities between 70-77% are usually most appropriate, while athletes seeking an optimal compromise of maximal strength and hypertrophy development may find that 77-85% is the best range when training for this outcome.
Intensities below 70% are best used for strength-endurance and in some instances for body composition training.
The amount of weight you aim to lift will influence all other loading parameters, including even exercise selection. This series of articles will explain how these training variables are manipulated to achieve a specific response that is optimal for an athletes performance in their sport.
A question that seems to be common among strength trainee’s is “how many reps & sets should I perform to get (insert objective here)?”
The answer to this question, unfortunately, is not as simple as you might assume. The truth is that two athletes can perform the same number of reps & sets and at the same % of their maximum, and still elicit different training effects.
There are many common factors which can contribute to this decision including range of motion, stance or grip, and even rest. However there is another key, yet little understood, variable that goes hand in hand with repetitions; Tempo.
The tempo that each rep is performed at will dictate the total time under tension (TUT) for any given set. This component is one of the major keys to achieving the desired training response. A better question to ask, may in fact be “what time under tension should I strive to achieve per set to get (insert goal here)?”
To understand tempo its important to understand the different types of muscular contractions, primarily concentric, eccentric & isometric. If you have skipped ahead, now is a good time to go back and learn about these! Each of these contraction types play a role at varying ratios in most strength training repetitions.
When prescribing tempo, we use a method popularised by the late strength coach Charles Poliquin. In this method a 4 digit system is used to represent the time it takes to complete the different phases of each repetition, for example “41X0”. Here, the first digit (4) prescribes the length of time to perform the eccentric lowering of the movement, for example lowering the barbell to your chest during a bench press. The second digit (0 in this example) refers to the moment when the bar has reached the bottom position of the lift. This is usually in the stretched position, and between the eccentric and concentric phases of the rep. Using the 41X0 example the athlete would hold that position for a count of 1, prior to initiating the concentric action. This action is represented by the third digit, most often written as “X” as in our example, particularly when assigned to an athlete who requires explosiveness for their sport. X implies that the movement should be performed at maximal effort/speed, it is important to note that it is the intent which matters most here and while the bar may in fact be moving quite slow during a heavy repetition, the attempt of the athlete to accelerate the bar is what is most important. Of course this third digit could also be a number, in which case the athlete would attempt to control the speed of contraction to match the prescription as may be the case with rehabilitation exercises or other supplementary lifts. Finally, the fourth digit refers to the time of the pause, if any, in the contracted position, usually the top of a particular range of motion.
To demonstrate how this may look for our two athletes and to illustrate how a different training effect may result, we will use the following examples. For this set, both athletes are to perform 6 repetitions of a front squat with varying tempo prescriptions.
TUT for each Rep = 8 seconds
TUT for each Set = 48 seconds (8seconds x6reps)
TUT for each Rep = 4seconds
TUT for each Set = 24 seconds (8seconds x6reps)
These two sets, while both performed for equal repetitions resulted in significantly different outcomes in terms of total time under tension.
Continue to the next article to understand how the optimal tempo, reps and time under tension are determined for a given training goal.