1) You Are Stronger Eccentrically
You are stronger during the eccentric phase of any lift—as much as 1.75 times as strong as during the concentric phase! Think about it: You can lower more weight in the bench press or deadlift than you can raise.
Remember, the eccentric phase of a lift occurs when the muscle lengthens. This is the down motion of the bench press, biceps curl, or squat. The concentric phase of the lift occurs when the muscle shortens, as in the up motion of the bench press, biceps curl, or squat.
2) For Maximal Strength & Hypertrophy, Control the Eccentric Phase of Every Lift: Never Let Gravity Do the Work
It is well accepted that the lengthening motion of an exercise triggers hypertrophy the most. Therefore, for strength and mass gains you NEVER want to ignore the eccentric motion of an exercise and let the weight fall with gravity.
You should always lower the weight in a controlled fashion and follow a prescribed tempo (a specific number of seconds to lower the weight).
3) The Eccentric Motion Causes More Muscle Damage & Hypertrophy
By programming the eccentric motion of your exercises, you can achieve the greatest muscle growth by making sure you have the right intensity of load and use the ideal time under tension to cause maximal muscle fiber damage.
Studies suggest that protein synthesis is greatest after eccentric-enhanced lifting. For example, a simple way to build more muscle is to use a longer tempo for the eccentric motion (4 to 6 seconds) with an explosive or 1-second concentric motion.
In studies that have compared eccentric-only and concentric-only training, eccentric-only is far superior for producing muscle damage and hypertrophy. This is because the eccentric motion damages the myofibers and it preferentially recruits fast-twitch fibers. This means there is a greater amount of stress per motor unit with eccentric exercises, producing greater muscle growth.
In contrast, concentric-only training doesn’t lead to significant hypertrophy. One well known study had males perform concentric-only or eccentric-only training using 4 to 6 sets of 8 to 12 reps 3 times a week. At the end of 12 weeks, slow-twitch fibers didn’t increase in either group.
But the fast-twitch type II fibers increased 10 time more in the eccentric-only group than the concentric-only group! Still, studies indicate that the very BEST stimulus for hypertrophy is training that uses both the eccentric and concentric motions but favors the eccentric motion—the reason is ATP or energy.
4) The Eccentric Motion Uses Less Energy
Another difference between eccentric and concentric motions is that the eccentric part of a lift requires less energy (or ATP) to complete. This is important because it means you can perform more work eccentrically, which has implications for body composition, strength, and size gains.
Let’s say that you are performing a set of squats with a heavy load and are nearing concentric-failure—for example, a load that is 85 percent of your squat 1RM and you are on the 6th rep of 8. Your muscles are running out of energy, or ATP.
You are close to being unable to sustain the contraction and lift the weight out of the squat. Upon reaching fatigue, the fibers physically “lock up” due to insufficient ATP, and if an eccentric action is then performed, small tears occur in the muscle, requiring muscle remodeling and growth.
5) Heavy Negatives and Forced Reps Produce an Anabolic Response
The locking up and tearing of muscle fibers is not the only reason eccentric training is superior for hypertrophy. Heavy negatives and forced reps are more advanced techniques that allow you to train at a higher intensity, thus producing greater stress and adaptation. These methods also trigger an anabolic, protein synthesis response.
For example, heavy negatives are performed with an above maximal concentric load—one that is 20 to 50 percent greater than your concentric 1RM. An ideal way to do this is with eccentric hooks that add weight, which you put on the end of a barbell. You lower the extra load using a prescribed tempo (4 seconds, for example), the hooks drop off when they hit the floor, and you raise the weight with the lighter load.
Studies show heavy negatives will produce greater motor unit recruitment, more protein synthesis, and a greater increase in insulin-like growth factor-1 than if lighter eccentric loads were used.
Forced reps will also recruit more motor units and lead to more growth hormone release. To do them, choose a load that is heavier than normal for the given number of repetitions.
For example, for a program that includes 4 sets of 8, identify the maximal load you can perform for 8 reps and then increase that load by 5 or 10 percent. Perform your intended 8 reps with the heavier load and use a spotter when you reach concentric failure to eek out a few more for a better anabolic response.
6) Eccentric-Enhanced Training Lets You Increase Concentric Power
A proven benefit to doing fast eccentric training is greater concentric power. An interesting study shows that eccentric-enhanced training will allow you to produce more power for sports such as football, rugby, lacrosse, and boxing and it provides variety to combat boredom for the recreational trainee.
This study used college athletes and tested the effect of using different eccentric loads with a set concentric load of 40 kg in the bench throw. Eccentric hooks were used on the barbell to test loads of 40, 60, 70, and 80 kg for the eccentric motion. The hooks dropped off at the bottom. Then the athletes explosively bench pressed or “threw” a 40 kg bar and power output was measured.
Results showed that the heavier eccentric loads (60, 70, and 80 kg) allowed the athletes to produced greater concentric power than the 40 kg load. The greatest concentric acceleration was produced with the heaviest 80 kg load.
Researchers think the athletes were able to produce more power because lowering a greater weight increases muscle tension and cross-bridging of fibers.
7) Fast Eccentrics Produce Hypertrophy in the Most Powerful, Biggest Type II Muscle Fibers
Fast and heavy eccentrics aren’t just for athletes. Anyone who wants to gain muscle size will benefit because fast eccentric actions cause more protein synthesis and muscle damage than slower eccentrics. Plus, they stimulate gene signaling pathways and activate satellite cells, which participate in muscle growth.
For example, one study compared an 8-week power training program using 30 to 60 percent of the 1RM with a traditional strength program using 70 to 85 percent of the 1RM. Results showed that the power training group had a much greater increase in type II muscle fibers than the traditional program.
8) Apply Fast Eccentrics with Complex Training To Get Bigger and Stronger
One of the best ways to apply fast eccentrics is to perform complex training in which you do a heavy strength exercise followed immediately by a fast power exercise. For example, do squats at 85 percent of the 1RM followed by vertical jumps.
In addition to activating the high-threshold motor units on the heavy, slower lift, your performance in the power exercise will benefit from pre-activation by the heavy load. Hang cleans followed by squat jumps are another option.
9) Eccentric-Enhanced Training Strengthens Tendons
Eccentric training is well known for strengthening tendons. Just like eccentric training is a robust stimulus for muscle growth, it also rebuilds tendon tissue. It is commonly used to rehabilitate ruptured tendons, but including eccentric training in your program can help you prevent such a debilitating injury.
10) Eccentric Training Increases Flexibility
Eccentric training has been shown to be one of the very best methods for increasing flexibility. It’s much more effective than static stretching, and a new analysis found that eccentrics can increase hip range-of-motion by an average of 22 percent. Range-of-motion in all joints measured was found to increase by at least 13 degrees.
It works because the eccentric motion causes muscle fiber growth, increasing the sarcomeres in series within a muscle, meaning the muscle becomes longer and you get more flexible.
Just about everyone wants to be more flexible, and the more technical lifts require a large degree of flexibility to perform them correctly. If your deep squat, deadlift, power clean, or front squat technique suffer due to poor flexibility in the ankles, hips, shoulders, or wrists, you won’t be able to get the most out of your training—and you’ll look like you don’t know what you’re doing. Eccentric training is the solution.