Science of Eccentric Training

Q: I hear good and not so good things about negative training. I get very sore when I do it, but I’m not sure if I’m benefitting or just damaging my muscles. What are your thoughts?

A: In popular bodybuilding videos you often see the stars lifting barbells and dumbbells explosively. You see them jerking up curls and presses, huffing and puffing their way to a monster pump—and finishing off by slamming the weights back onto the racks at exhaustion. Perhaps that is a bit of Hollywood embellishment, but somewhere along the way to learning how to “lift things up and put them down,” bodybuilders, personal trainers and strength coaches have forgotten about eccentric, or negative, training.

Just to make certain we’re on the same page, let’s review what happens during an eccentric contraction: The muscle lengthens while producing tension, thus braking or controlling the speed of movement. As such, during a bench press, lowering the weight to the chest would be considered the eccentric contraction. Research shows that of the three types of contractions, eccentric will produce the most muscle soreness and mass. Here are examples of how to emphasize eccentric contractions in four popular exercises:

Leg curls. Exercise machines offer greater stability than free weights, and with a leg curl machine you can take advantage of that difference by lifting the weight with two limbs and lowering with one. Obviously, you can also use this technique with leg extensions—but don’t use it on a conventional leg press because of the high shearing forces that placed on the pelvis.

Back extensions. To increase the eccentric overload to better match the strength curve on this exercise, hold a dumbbell close to your chest, proceed to the top position, and then extend the dumbbell in front of you. Lower slowly. By changing the leverages, you increase the resistance at the top of the movement. This technique is more difficult than you might think, and most trainees will find it sufficient to use a light weight, such as 2 1/2 to five pounds.

Chinups. A lot of trainees, especially women and those who are overweight, cannot perform a single chinup (palms facing the body) or pullup (palms facing away from the body) in good form. Eccentric training is ideal for quickly achieving that goal. Have a training partner help you lift one leg (keeping it back, behind you) and assist so that you can lift your chin over the bar. At that point the partner lets go (or holds on lightly without providing assistance), and then you lower yourself to extended arms. Another version is to set a barbell at hip height or slightly lower in a power rack, and then rest the fronts of your ankles on the bar as you pull yourself to the top of the rack. That will reduce the amount of bodyweight you have to lift. As a general rule, when you can lower your body to a count of 30, you should be able to perform a single concentric, or positive, rep in good form.

Shoulder external rotation. The rotator cuff muscles are important for sports that involve throwing, as they help decelerate the arm. They are also important for sports in which there is little eccentric movement, such as swimming, where structural imbalances often develop that can increase the risk of injury. This external-rotation movement is done on a cable. With the cable handle in hand, position yourself with your arm bent at 90 degrees and your upper arm pinned at your side. Pull perpendicular to your body, using your free hand to help yourself pull the weight to the midline position. From there release the free hand, and slowly allow the cable handle to return to the start position. You will find that you can use considerably more weight on these than you can when you perform conventional external shoulder rotation.

Because fewer of a muscle’s motor units contract during an eccentric contraction, negative training can generate up to 1.3 times more muscle tension than concentric training. Greater tension provides increased stimulus to the muscle fibers, which in turn encourages greater biological adaptations.

Of course, there are a few disadvantages of eccentric training. Embarking on it too early in your athletic career can damage connective tissues and place you at a high risk of muscle injury. Further, it takes considerably longer to recover from workouts that emphasize eccentric contractions vs. conventional workouts. Specifically, it can take seven to 10 days to completely recover from an eccentric workout, so you want to avoid it when you’re doing in-season workouts. In addition, for many exercises that use heavy weights, such as squats, you will need several well-trained spotters to lift the weight for you.

Strength coaches recommend using anywhere from 100 to 175 percent of maximum for optimal loading in eccentric work; however, it’s tempo that dictates the optimal weight. You should have a predetermined period for lowering in your mind—say, six seconds—before doing your set. Muscle failure in a properly performed eccentric exercise is associated with a response in which the muscles are shaking involuntarily as they do their decelerating work.

Try to visualize your muscles as giant brake systems that decelerate the resistance. If you start lowering the weight faster than the predetermined time, it’s time to terminate the set. Note that the greater an exercise’s range of motion, the longer the preset lowering time.

Besides the slow lowering of supramaximal loads, there are many other ways to perform eccentric training. In what’s called “complex training,” athletes achieve hypertrophy through a combination of lifting maximal loads of one to five reps and fast eccentric training, meaning plyometrics. One example is to superset six sets of five reps in the squat with five reps of hurdle jumps. The rationale is that the heavy sets tap into the high-threshold motor units, and the plyometric movements create muscle fiber damage that leads to the hypertrophy of the high-threshold fast-twitch type 2B fibers. Keep in mind that this is an advanced method. For more on complex training, see Chapter 7 of my book Poliquin Principles.

Editor’s note: Charles Poliquin is recognized as one of the world’s most suc-cessful strength coaches, having coached Olympic med-alists in 12 different sports, including the U.S. women’s track-and-field team for the 2000 Olympics. He’s spent years researching European journals (he’s fluent in English, French and German) and speaking with other coaches and scientists in his quest to optimize training methods. For more on his books, seminars and methods, visit www.StrengthSensei.com. Also, see his ad in this issue.   IM