A rep – short for repetition – is the fundamental element of any weight lifting programme.
If you do not execute a rep correctly, you won’t achieve the adaptive response you are after, whether that is an increase in strength or size.
When you consider all of the reps you do in a month, often ranging in the thousands, its makes sense to understand this most basic, yet extremely important element of weight lifting.
Defining the rep
The rep is defined as a single cycle of a lift. You should perform each rep in a controlled manner, using the correct form, technique and tempo for specific exercises and goals.
You perform two or more reps consecutively to complete a set. A weight training programme typically defines exactly how many reps you need to perform for every set but it seldom defines elements such as timing or tempo.
From a rep structure point of view, the number of reps you complete in a set is governed by the training principles of adaptation.
By the numbers
Low reps will elicit a different response to higher reps, for instance, as these rep structures target different energy, neural and metabolic pathways.
A low rep range between 1-5 is normally used to increase strength and power and generally triggers neurological adaptations as more muscle fibres are recruited to execute these short-duration, high-intensity, often forceful reps.
The rep range that best targets muscle growth (hypertrophy) and structural adaptations is the 6-12 rep range.
When we get into the 13+ rep range, we start initiating metabolic and cellular adaptive responses, like improving lactate thresholds or burning more energy per exercise.
Breaking down the rep
From a mechanical perspective, a rep consists of three distinct phases:
- Concentric
- Transition
- Eccentric
The concentric phase is where the muscle contracts (shortens) when lifting or pulling the weight.
The transition phase is the mid-point of the rep and is generally considered to be the peak point of the contraction. This is followed by the eccentric (lengthening) phase used to return the weight to the starting position.
The eccentric phase also involves muscle contractions, but this is generally in the form of the antagonist muscles contracting to return the agonist (exercise-initiating) muscle to its resting position in a controlled manner.
The technical stuff
Breathing during your rep is also an important consideration. The best technique is to exhale on the concentric phase, which is the when you exert the greatest force, and inhale on the eccentric (lengthening) phase.
The other key element of a rep is the tempo, which refers to the rate or speed at which you lift or pull the weights.
A commonly used tempo is 3:1:3, which denotes the seconds for each phase – the concentric, transition and eccentric phases. When a fourth number is used, for example 1:2:1:2, it generally refers to the pause at the bottom of the movement (i.e. not the transition phase).
Using a specific tempo can help you target specific energy systems and muscle adaptations by increasing the amount of time your muscle spends under tension, as well as limiting the amount of swinging and momentum used in your lifting technique. This further assists in recruiting more muscle fibres in each rep, which will ultimately build more shapely muscles.
Author: Pedro van Gaalen
When he’s not writing about sport or health and fitness, Pedro is probably out training for his next marathon or ultra-marathon. He’s worked as a fitness professional and as a marketing and comms expert. He now combines his passions in his role as managing editor at Fitness magazine.
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