How should you think about the benefits during lifting (concentric) and lowering (eccentric) of the weight during your workout? Maria Ekblom from Team EBT summarizes the studies on the topic!
Resistance training involves two types of movements, concentric and eccentric. Concentric movement is when the muscle shortens while producing force (contracting the muscle). This happens when you are raising the weight during a biceps curl. Eccentric movement is when the muscle lengthens while producing force, like when you’re lowering the weight back down during a biceps curl. One can say that you’re often stronger in the eccentric phase of the lift since you’re holding back the weight.
Eccentric Training Creates More Muscle Damage
Both movements are said to lead to increased hypertrophy/muscle mass. Some evidence suggests that eccentric training promotes muscle mass more than concentric. This may be due to a more rapid response of muscle building (anabolic) signaling and induced muscle damage.
The hypothesis is that more muscle damage mediates a greater anabolic response, and that response strengthens the muscle. However, no one really knows the exact mechanism that causes muscle to grow, and EBT has previously written about the relationship between muscle damage and muscle growth.
Most studies favor the eccentric movement to produce a higher increase in muscle hypertrophy compared with concentric training, however, the difference in effect is very small – on average 3.2% more muscle growth from eccentric movements, without statistical significance (1–2).
If There is a Benefit it is Probably Very Small
More studies have come to the same conclusion (3–5), that there’s no difference in muscle hypertrophy between concentric and eccentric training. There may be a slight advantage to eccentric but if there is, it’s a very small one and probably not significant.
It Might Just Be the Weight!
Loading differences between the two movements can contribute to the small advantage of eccentric lifting. During eccentric lifting one often tend to use a heavier weight. It may also be because you’re nearing your maximum and therefore lifting more weight. Growth-related effects of eccentric training appear to be related to the higher loads developed during eccentric contractions (6–8).
Regardless, this research suggests that whole muscle growth is best achieved by performing a combination of both concentric and eccentric movement during resistance training (1).
Post provided by @maria_ekblom, a member of #teamEBT. Licensed physiotherapist and personal trainer.