As is commonly known amongst fitness circles for a muscle to fully contract it needs to do two things- it needs to “stretch” and “flex”. For this article I will be using the proper names for the these being eccentric and concentric, for clarification eccentric refers to the “stretching” phase of the movement and concentric refers to the “flexing” phase of the movement. To put this into a real life example- the bottom part of a bicep curl would be the eccentric motion as the bicep muscle is stretched, while the top part of the curl would be the concentric motion as this is the “flexing” motion. So with this in mind I will enter into the true meaning of the article.
A long time ago a gym regular and close friend told me about how “squeezing the muscle at the concentric point will increase gains. I am sorry to say that I did not really take this on board until about 12 months later. I started with squats- making sure to always squeeze my glutes, hamstrings and quads. Then I moved to my shoulder session- and so on. It is safe to say that I should have listened to this advice sooner. But what really is it? And how does it work?
Well, like I briefly mentioned in the initial paragraph for a muscle to work there needs to be an eccentric and concentric phase. It is the transition, under a load, that causes muscle fibres to stress and damage. So if you can, in anyway, increase the difference between these two phases then the damage and hypertrophy will increase. Increased hypertrophy will therefore mean more muscle mass built. Seemingly it increases the intensity of a workout, but does it impact recovery?
In short, no. It does not. As this handy graph I found shows the optimal sets per body part is 3-5. Anything below that will not create enough hypertrophy and anything above that will impact recovery. Simply performing your reps with that squeeze will not tip you over into the over training section.
But there is even more that you can do on a rep by rep basis to make the most out of what you have. By slowing down the eccentric portion of the movement. Heres why…
To try and break things down I shall translate the four parts of this graph.
- A large force (heavy weight) eccentrically creates a small velocity
- A small force (less weight) eccentrically will create a large velocity
- A large force (heavy weight) concentrically will create a small velocity
- A small force (less weight) concentrically will create a large velocity
Basically if you want to lift something with speed then use a slower force. If you want to lift slowly then use a larger load.
So with these principles in mind we can begin to tackle why you should slow down the eccentric motion. As I am sure you all know, and have experienced, the lower part of the bicep curl is much easier than the top part. In science terms- the eccentric part is much easier than the concentric part. This is for a number of reasons. Firstly often times you are not working against the effects of gravity in the eccentric phase and secondly you are naturally 30-50% stronger on the eccentric phase as per a 2015 study. But an issue arises. To lift any kind of load you need to be equally strong on the eccentric as you are on the concentric. This is why you slow down the eccentric motion- by making it harder you even out the strength imbalance and ensure strength for the future.
Now, this is all well and good, but how does it link with the title? Well by keeping slow and steady in mind you can utilise the squeeze and slow eccentric to its fullest effect. Keeping calm and collected under the weight will not only improve the effectiveness of the lift but also allow you to perform these two key actions.
Thank you for sitting through that- the sports science geek inside me was loving every second of that. Any questions then do ask me as there are some fairly complex ideas in here and I would have failed if you did not understand what they are.