By Todd Bumgardner ProSource
As lifters, we often only consider a lift's concentric phase, the phase that takes the barbell from the bottom position to the top position, reinforcing success on the way. But this limited view confines our training potential. We narrow our focus too greatly and miss the benefit of eccentric-emphasis lifts.
Eccentric-focused lifts offer size and strength potential that boosts performance and aesthetics.
What is an Eccentric Contraction?
Let's do a swift and informal muscle contraction review.
Eccentric contractions occur when a muscle contracts while lengthening . Visualize your pecs and triceps lowering the bar while bench pressing. These under-utilized strength heroes are accompanied by isometric and concentric contractions.
During an isometric contraction, the muscle doesn't change length. Concentric contractions, however, shorten muscles. Envision your pecs and triceps while pressing the bar.
Eccentric contractions take us to the bottom position of most barbell lifts (squats, presses, rows, etc.), an essential lift phase that's disregarded.
Benefits of Heavy Eccentrics
Eccentric-emphasized reps are an often-untapped size and strength resource. The benefits, however, are backed by science and thousands of hardworking reps.
Eccentrically emphasized lifts keep muscles under tension longer than lifts performed at even tempos. Time under tension tells the CNS and the peripheral nervous system that the task is important and it needs to beef up musculature to meet demands.
Lengthening contractions are also more inflammatory than isometric or concentric contractions. That means more muscle damage and more signaling that there's been a massive disruption to be dealt with. Muscle damage, when accompanied by appropriate rest and nutrition, can lead to fantastic hypertrophy.
Strength and Power
Where muscle fades into tendon, there is a nervous system device called the golgi tendon organ (GTO). It's a peripheral nervous system minion that monitors and maintains muscular tension. If it denotes a marked, rapid increase in tension it inhibits neural drive to the muscle to reduce the tension and prevent tearing. The GTO is active at all levels of muscular contraction. It doesn't require great force for it to appraise the muscular situation. It will, however, end a contraction it deems damaging.
It's a great, inhibitory reflex if you're in a survival situation and muscle tearing ensures sudden death, but it's a drag if you're training to display strength and power.
Extended, heavy eccentrics seem to hinder the GTO, allowing muscles to handle greater forces at higher speeds. This inhibitory GTO training increases muscular reactivity; strength and power are displayed at faster rates.
The main heavy eccentric exercises I use are squats, bench presses, bent rows and Romanian deadlifts. Why? These exercises are easily, and safely, loaded with an extended eccentric contraction. They also offer enough input to invoke strength and size adaptations, but not so much that your nervous system overloads.
I avoid using conventional deadlifts and overhead presses in the heavy eccentric format. Deadlifts are too CNS taxing and the overhead press risk far outweighs the reward.
Performing the Eccentric-Based Rep
What should an eccentric-based rep look and feel like?. Slow and controlled during descent, violent during ascent.
Think of slowly pulling yourself into the bottom position while keeping time with a cerebral metronome that ensures you lower at the precise pace. The pull to the bottom feels like a squeeze, think of slowly coiling yourself like a spring.
Once you hit the bottom position, you're off like a rocket. There's no pause in the bottom and the concentric phase is performed as rapidly as possible.
How to Implement Heavy Eccentrics
An eccentric phase lasting four to six seconds per rep works well to turn off the muscular governor and create hypertrophy inducing stress.
Eccentric phases last from two weeks to a month, depending on the trainee's goals. Performance goals require faster transitions into training phases that accentuate the other muscular contractions. More frequent change increases speed and power adaptations. After two or three weeks you're moving on.
Aesthetic goals, however, specifically hypertrophy, require the eccentric phase to exist in the training plan for longer. They'll last for three weeks to one month; the extra weeks create more total eccentric volume that enhances hypertrophy.
You'll do eccentrically-based lifting during every training session while in a heavy eccentrics phase, from two to four training days per week, depending on time and goals.
Folks with performance goals may utilize two eccentric days while hypertrophy-focused trainees employ four day eccentric templates.
Eccentric phases are utilized several times throughout the training year, between two to four times, depending on how long each phase is designed to last. Most often eccentrics exist early in the training year, promoting hypertrophy for aesthetic athletes and strength and healthy tissue adaptations for sport athletes.
How Many Exercises?
It's often that every exercise in a hypertrophy program eccentrically based will consist of four to five big, compound lifts. Strength and power programs, however, differ. It's often that only the main exercise emphasizes the eccentric contraction, while the rest of the movements are performed using normal tempos.
The answer lies in the goal. Need more hypertrophy inducing stress? Use more eccentrics. Training to be stronger and faster? Use the eccentric to catapult your power during your main exercise.
How Many Reps?
Again, it depends mostly on the percentage of load used.
Sets performed in the eighty percent to eight-five percent range use one to three reps. This rep and load combination offers enough stress to train strength and power without promoting bad form or (even worse) rep failure. Use between three and five sets while loading in this heavy percentage range.
Sets performed in the seventy to eighty present range (usually assistance work) are done using up to five reps per set. Lots of time under tension with an appreciable load, this means strength and muscle. Use between four and five sets for assistance eccentrics.
A cautionary note: avoid eccentrically-emphasized reps with loads at or above ninety percent of one rep maximum. The risk of injury greatly outweighs the potential strength benefit.