The Power of Eccentric Training

By Poliquin Group™ Editorial Staff
1/10/2014 3:07:12 PM

In popular bodybuilding videos often you’ll see the stars lifting barbells and dumbbells explosively. You’ll see them jerking up curls and presses, huffing and puffing their way to a monster pump – and finishing off by slamming the weights back into the racks in exhaustion. Perhaps this 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 all but forgotten about eccentric training.

Just to make certain we’re on the same page, here’s a reminder of the three types of muscle contractions:

Concentric. A muscle develops tension, causing movement to occur.

Isometric. A muscle develops tension while its length remains unchanged, thus producing no external movement.

Eccentric. A muscle lengthens while producing tension, thus braking or controlling the speed of movement.

During a bench press, for example, lowering the weight to the chest involves an eccentric contraction; pausing with the bar on the chest involves an isometric contraction; and pressing the weight to extended arms involves a concentric contraction. Of the three types of contractions, research shows that eccentric contractions produce the most muscle soreness and muscle mass.

There are basically two types of eccentric contractions: fast and slow. Performing a heavy squat requires slow eccentric contractions of the posterior chain and quadriceps, and jumping requires fast eccentric contractions of the hamstrings. Because slow eccentric training is associated with a decrease in the rate of force development, it should be used mainly in the preparatory period. Fast eccentric training, such as plyometrics, should be reserved for the competitive period.

Eccentric strength is specific to many sport movements. During the follow-through of a baseball pitch, the involved muscle groups must provide important decelerative contractions to preserve healthy joint functioning (arthrokinematics). It’s interesting that many textbooks on overuse injuries prescribe eccentric training to rehabilitate overuse injuries yet do not prescribe eccentric training to prevent them.

Eccentric strength is also important in many sports that require exceptional jumping ability, such as figure skating and gymnastics, as athletes in these sports need high levels of eccentric strength to control their landings and minimize the stress on the joints.

In a research paper written by New Zealand sport scientist Warren Frost, major sports were classified according to the level of eccentric activity they require. The highest levels of eccentric strength were reported to be in sports such as American football, figure skating, gymnastics and downhill skiing. Sports such as golf, field hockey and baseball were considered sports that rely more on concentric contractions.

Because fewer motor units of a muscle contract during an eccentric contraction, eccentric 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. The late Per Egil “Pella” Refsnes, a respected strength coach from Norway, advanced that eccentric training is the single-best method to boost strength levels in elite strength athletes. In fact, eccentric strength can improve performance in many exercises; there is research showing that powerlifters (using no supportive gear) who could lift the heaviest weights in the bench press were the ones who could lower their weights more slowly.

Of course, there are a few disadvantages of eccentric training. Embarking on eccentric training too early in an athlete’s career could damage connective tissue and place the athlete at a high risk of muscle injury. Further, it takes considerably longer to recover from workouts that emphasize eccentric contractions versus conventional workouts. Specifically, it can take seven to ten days to completely recover from an eccentric workout, so this type of training should be avoided with in-season workouts.

Many exercises that use heavy weights, such as squats, require several well-trained spotters. In addition, there are several unique pieces of training apparatus that are especially suited for eccentric training, such as eccentric hooks that release additional weights when the attached weights touch the floor (so there is more resistance in the eccentric range than in the concentric).

Practical Applications of Eccentric Training

Strength coaches recommend using anywhere from 100 percent to 175 percent of maximum for optimal loading in eccentric work. Tempo will dictate how much weight to use in eccentric work; you should have a preset time of lowering (e.g., 6 seconds) in your mind 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.

Athletes should try to visualize their muscles as giant brake systems that decelerate the resistance. If you start lowering the weight faster than the preset time, it’s time to terminate the set. Also, the greater the range of motion in the exercise, the longer the preset lowering time.

Other than slow lowering of supramaximal loads, there are many other ways to perform or combine various forms of eccentric training, one of which is a method called complex training. To achieve such hypertrophy athletes could combine lifting maximal loads (1-5 RM) and fast eccentric training (plyometrics). One example is to superset 6 sets of 5 reps in the squat with 5 reps of hurdle jumps. The rationale is that the heavy sets tap into the high-threshold motor units, and the plyometrics create muscle fiber damage that leads to the positive adaptation or hypertrophy of the high-threshold fast-twitch Type IIb fibers.

Caution: Do not attempt any advanced, complex training methods until you have achieved a continuous, progressive buildup of eccentric training. This progression can be broken down into the following six levels:

Level 1
This level is for the athlete with less than two years of training experience. No training with eccentric loads is needed; the simple lowering of loads under control should suffice.

Level 2
Use 70 percent of maximal load (1RM). Go to concentric muscle failure and then do 2-3 forced repetitions with the same load. Repeat for 2-3 sets. As a variation, you could perform only one forced rep, but try to stop the descending weights three times for a count of four seconds.

Level 3
Use 70 percent of maximal load. Go to concentric muscle failure and then do 2-3 forced repetitions with 15 percent more weight. Repeat for 2-3 sets.

Level 4
Use 80 percent of maximal load. Go to concentric muscle failure, and then do 2-3 forced repetitions with 20 percent more weight. Repeat for 3-4 sets. As an alternative for Levels 3 and 4, a training partner can manually apply resistance (i.e., push down on the bar) for the eccentric portion instead of adding weight. These additional negative repetitions will exhaust eccentric strength levels after you achieve concentric muscular failure.

Level 5
Using 110-120 percent of maximal load, do 4-6 eccentric-only reps for 4-6 sets, resting 4-5 minutes between sets. Take 8-10 seconds to lower the weight in each set.

Level 6
Using 125-140 percent of maximal load, do 2-3 eccentric-only reps for 5-6 sets, resting 4-5 minutes between sets. Take 4-6 seconds to lower the weight in each set.

Individuals embarking on an eccentric strength training cycle will be exposed to increased connective tissue damage, increased myofibrillar damage and higher cortisol levels. Nutritional supplements to help deal with this stress include BCAAs, beta alanine and vitamin C.

Eccentric training is a powerful tool that will take you to the fringe of serious training, but it’s one that few trainees are using to the extent they should be. So as the massive bodybuilder on the popular Planet Fitness commercial might say, “I lift things up and put them down…slowly!”

Source: http://www.poliquingroup.com/ArticlesMultimedia/Articles/Article/1097/The_Power_of_Eccentric_Training.aspx