As shown by various studies and field observations, speed of execution of exercises may be one of the various parameters that may have an impact on muscle hypertrophy.
What is the relationship between hypertrophy and speed of movement execution?
In 2009, the International Journal of Sports Medicine published a study conducted on seniors by Nogueira and colleagues, showing that performing concentric contractions at the rate of one second had a higher efficiency on muscle development, compared to a rate of 3 seconds.
This study showed that a faster speed of execution was more effective in both the upper and lower limbs. This difference can be attributed to increased recruitment of motor units due to increased fatigue. Paradoxically, other studies (1-2) show that training at moderate speed is also highly effective.
This may seem contradictory, but in fact it underlines the complementarity of the different speeds of contraction, because for more moderate speeds it is no longer fatigue and the increase in the number of motor units that are in the foreground, but ischaemia, hypoxia and therefore an increased metabolic requirement. (3)
Although concentric and isometric contractions provide good answers regarding hypertrophy, it seems that the speed of execution of the eccentric phase of a movement may be even more important.
A large majority of studies emphasise the effectiveness of eccentric work, basing this superiority on greater muscle tension, with collateral effects including a faster rise in protein synthesis and a greater increase in IGF-1 levels.
To complete this advantage, we can add a selective recruitment of fast fibres, which effectively creates a scenario very favourable to muscle hypertrophy, the latter being the most voluminous. (4) It is therefore understandable that for eccentric contractions, the different variations in the speed of execution must be taken into consideration.
To summarise the various studies concerning the speed of execution of exercises and our personal experience, we can consider that speeds of between 1 and 4 seconds for concentric work and 2 to 6 seconds for eccentric work can be recommended.
If, as we have mentioned, certain results may seem contradictory, this in fact only highlights the importance and complementarity of the interactions of the different modes of contraction and the speed of execution of the exercises. The important thing is to make these parameters coincide with the objectives and to know how to organise them within the session and to plan them during the different training cycles.
Note: We have already dealt with the choice of exercises, intensity, volume and rest intervals in previous issues.
