Sorry for the click bait title but I promise you will be amply rewarded. The world of ‘fitness’ is often battered with so much information that it can be overwhelming. Who do we trust? What is the best way to [insert activity/ process here]. It is often easy to find what has worked in the past and stick with it. How many of us continuously perform the same movements every week because it is what we know and it is what has worked in the past? What if I told you there was an easy way to change up your normal routine so you could BUILD MUSCLE FASTER? In this short blog I break down a very interesting study with the answers you have been seeking. We will not be discussing frequency and how often you should be lifting. If you want to learn more about that checkout my previous blog post here.
Before we dive in, I want to define a few terms for you.
Concentric Muscle Contraction
This involved the muscle shortening. The origin and insertion of the muscle get close together. Think of performing a bicep curl from arms fully hanging to bring weight towards your shoulders. – BBC
Eccentric Muscle Contraction
This involves the muscle lengthening while under tension. Th origin and insertion move further away from each other. Think of lowering a bicep curl with weight, slowly back to arms fully hanging. – BBC
Isometric Muscle Contraction
The muscle produces tension but there is no change in length. Think of performing a bicep curl half way and holding it. Your biceps will be contracted, but there is no further change in length. – BBC
Muscle hypertrophy is growth in the muscle tissue. Placing a larger than average load on the muscle tissue and lifting against gravity creates damage in the tissue. The body utilizes multiple cells/ processes to repair the damaged muscle fibers but in doing so creates thicker fibers.
How long does it take to create muscle hypertrophy?
Recently, research has shown that muscle hypertrophy that occurs at initial stages of resistance training (~4 sessions) is mostly attributable to muscle damage induced cell swelling with the majority of strength gains resulting from neural adaptations (8−12 sessions). Within the latter phase of resistance training (6−10 weeks), muscle growth begins to become the dominant factorDamas F., et al.
With this study, we need to keep in mind:
- sex of the individual
- history of resistance training experience
- socioeconomic factors
There are many pieces to training but the overall consensus is 6-10 weeks for most healthy individuals.
Lets Dive In
Now that we have a few definitions under our belts, lets dive into the study:
Researchers compared 20 different studies to find the overall effects of concentric versus eccentric on muscle mass and strength in HEALTHY individuals.
Who was studied?
Men and women with mean ages ranging from 19 – 33 years old.
How long did the studies last for?
Researchers followed participants between 4 – 12 weeks with the mean ranging around 10 weeks total.
How often did they exercise?
2-4 sessions per week
What muscle group did they test for strength/ mass?
- Knee extensors (Quadriceps)(15 studies)
- Elbow flexors (Biceps) (3 studies)
- Rotator cuff (2 studies)
Since human movements result from the combination of different muscle actions, total strength was calculated as the average of the strength gains (average peak torque or 1 RM) of the three different types of muscle contractions used while testing (average of concentric+eccentric+isometric torque). The meta-analyses of all participants in 15 studies, regardless of whether they trained at higher or equal eccentric than concentric training intensities, showed no difference in improved total strength.Damas F., et al.
Meta-analyses of those training at a higher eccentric than concentric intensity showed significantly greater increases in eccentric peak torque of 13.71 N.m.Damas F., et al.
When do we use eccentric strength? Some examples include walking down stairs, slowing down from a sprint, running downhill, lowering weights, lowering into squat position, push ups, pull ups, etc.
The meta-analyses showed no significant differences in concentric strength gains of participants training eccentrically compared with concentrically regardless of the overall or subgroup analyses.Damas F., et al.
Meta-analyses showed no difference in isometric strength gains between participants exercising eccentrically compared with those exercising concentrically at different or equal training intensitiesDamas F., et al.
Meta- analyses on all studies and the subgroup analysis demonstrated significantly greater increases in muscle mass as measured by girth by 0.46 and 0.49 cm, respectively, among participants exercising eccentrically compared with participants exercising concentrically.Damas F., et al.
Some things to note
- It should be noted that a majority of the studies found greater muscle mass results from increased intensity.
- Muscle girth measurement has user error and is difficult to replicate precisely between researchers.
- A variety of tools were used for muscle mass density including MRI, DEXA, ultrasound, and CT Scans.
There you have it, eccentric strength training to build more muscle! Try incorporating this into your routine 1-2x per week and see what you think!
Damas F., Libardi C.A., Ugrinowitsch C. The development of skeletal muscle hypertrophy through resistance training: The role of muscle damage and muscle protein synthesis. Eur. J. Appl. Physiol. 2018;118:485–500. doi: 10.1007/s00421-017-3792-9.
Roig M, O’Brien K, Kirk G, Murray R, McKinnon P, Shadgan B, Reid WD. The effects of eccentric versus concentric resistance training on muscle strength and mass in healthy adults: a systematic review with meta-analysis. Br J Sports Med. 2009 Aug;43(8):556-68. doi: 10.1136/bjsm.2008.051417. Epub 2008 Nov 3. PMID: 18981046.