When those butterflies reach up into your throat, what’s your focus? Our guess is that you’re concentrating not just on the required movements but on performing them as fast as you possibly can. Let’s face it, all things being equal, speed wins. Whether the WOD is an AMRAP (as many rounds/reps as possible in a certain time period), an RFT (rounds for time) or even an EMOM (every minute on the minute), speed of movement means efficiency, less work, more rest and, ultimately, success.
To be fast, CrossFitters learn and adapt. And the primary way we learn to increase speed of movement and efficiency is to reduce unnecessary movements, thereby conserving energy. What are unnecessary movements? They are the lowering/negative phases of the movements, which at the level of the muscle are called “eccentric” actions. And therein lies a potential problem.
Types of Muscle Contractions
Biologically, a muscle contraction is simply “an attempt to shorten” a muscle, which causes movement at a joint because the shortening muscle pulls on bones. Too often, athletes and coaches assume that a contraction necessarily entails a shortening of the muscle. It does not. Recall that there are three general types of muscle contractions:
1. A concentric contraction occurs when the active muscle produces a force greater than the resistance it is opposing. In that case, the “attempt” is successful; the muscle is capable of overcoming the resistance, so it shortens and creates movement at the joint.
2. An eccentric contraction is one in which the active muscle does not produce sufficient force to overcome the resistance. Therefore, the attempt to shorten is unsuccessful, and the muscle lengthens against the resistance.
3. An isometric contraction is one in which the amount of force produced by the muscle equals the resistance, so no movement occurs. Think of your hands against the floor in a plank or your deltoids holding a bar in overhead lunges.
It’s also important to understand that we can’t look at joint movements to define what is happening at the level of the muscle; contractions and joint movements are two different things altogether. For example, if you look at a standard biceps curl, you would be correct to say that in a successful lift, the biceps are contracting concentrically. In that case, the triceps are allowing the movement by relaxing. However, if I add 100 pounds to your curl at the top of the movement and you can’t hold it, you’ll begin to lower the bar even though you’re fighting with all your might to curl it back up. Your biceps are contracting eccentrically, but — and this is important — your triceps are not contracting concentrically, even though the joint action is elbow extension (which is normally caused by concentric triceps contraction).
Further, when it comes to eccentric actions, keep in mind that you can intentionally create an eccentric contraction. For instance, in a front squat, you can and often do purposefully control your descent. As you descend, your quadriceps contract eccentrically against the resistance. In a submaximal front squat, your quadriceps can overcome the resistance (they have sufficient force to cause a concentric contraction, which they will perform on the way up), but you consciously control the descent by applying only the right amount of quadriceps force in order to descend at the appropriate speed.
The Importance of Eccentric Contractions
And again, speed is what’s at issue here. Often, in a WOD, we focus on speed, which means we perform explosive concentric contractions while minimizing time in the lengthening/negative phase. Eccentric work gets cut out of the mix.
For instance, in “Randy” (75 snatches for time), do you consciously lower the bar with the same effort and control with which you pulled it overhead? No. In “Grace” (30 clean-and-jerks for time), do you bring the bar back down to the rack position and then descend as you ascended? No. You descend as fast as you can, often coming close to simply dropping the bar. Controlling the negative portion of the lift would take more time and energy.
The problem is, eccentric adaptations are required for muscles to develop fully and comprehensively. In fact, eccentric training is so important to athletic performance that there are now companies designing what are called “accentuated-eccentric load” machines. This equipment increases the weight when an athlete gets to the eccentric portion of the movement.
Here are some reasons we need eccentric work to be fully prepared functional athletes.
You’re stronger in the eccentric part of any lift. In fact, studies show that you’re roughly 1.5 to 1.75 times stronger in the eccentric portion of a lift than the concentric portion. Avoiding the eccentric portion of the lift means missing out on strength adaptations our bodies would make by encountering loads we’re capable of resisting in the negative phase but which we can’t overcome in the positive phase.
Eccentric training creates greater intramuscular friction between muscle microfilaments (actin and myosin). This friction brings about damage and subsequent repair, and that repair means growth in muscle size.
Strength in connective tissue is enhanced by eccentric actions much more than by concentric or isometric work. Stronger connective tissue reduces risk of injury and assists in stabilizing joints.
Range of Motion
Eccentric loading with heavy weight has been shown to improve flexibility. The intramuscular friction from the negative movement promotes not only greater muscle size but also increased muscle fiber length, and longer muscles can move through a greater range of motion. One study, published in 2004 in the Journal of Athletic Training, found that eccentric training can improve joint mobility by 20 percent or more.
More Power, Earlier
Because eccentric work can handle heavier loads, muscles working eccentrically call on more type II muscle fibers. These fibers, also called fast-twitch, produce more force earlier in the movement. The more you train these fibers, the more they grow, ultimately allowing for more power earlier in your lifts.
A good box ensures its athletes do not become WOD-only athletes. One criticism of CrossFit is that it tests strength, power, endurance and agility without building them. That’s why athletes really need to work at the MOD (movement of the day; sometimes also called “skill work”).
The MOD should be where strength and technique are built. This is also where eccentric training should be standardized. Sure, some of the descent on a wall ball during a WOD will be a ballistic drop, but that should only be made possible by practicing a good slow-speed squat that incorporates controlled eccentric and concentric contractions. The focus of a MOD ought to be on building physiological factors that can be tested in a WOD. Eccentric or negative training must be a regular part of that training.
With eccentric-only training, begin the movement at the point at which the concentric portion of the prime movers (the muscles primarily involved in the lift) ends. So, in the case of a shoulder press, you start the movement from the lockout position, get under it and slowly lower the weight. Remember that you can lower more weight than you can raise, so (after a good warm-up), don’t hesitate to challenge yourself.
Eccentric-only training can be quite metabolically costly. Prepare to be taxed. Keep the volume low and focus on two to three sets of three to four of 110 to 120 percent of your maximum.
Try this. In a squat, ascend (or execute the concentric phase) at normal speed and then descend twice as slow as you ascended. Concentrate on counting at a normal pace, being sure to be consistent.
Once you’ve mastered that, try a set or two at three times as slow on the way down. The optimal rate is 1:4 (one second up, four seconds down). This will take some real stability and stress your technique, but in the end, it will improve your mechanics, range of motion and muscle strength. That increased strength will translate into power during a WOD. Here, because you are working with submaximal loads, your volume can be a bit higher; try four to five sets of six to 10 reps at 70 to 80 percent of your maximum.
In partner-assisted eccentric training, often referred to in globo gyms as “negatives,” you will use loads above your maximum. Your partner can assist by helping you get positioned under a weight and slowly giving you more and more of the load until you have control of the weight. Immediately, the weight will drive you into the negative phase. Fight the weight on the way down, and be careful to not descend too quickly because that may predispose injury.
Communication with your partner here is critical. You should be prepared mentally and physically for what will be a very high workload; it is quite taxing to drive with all your might against a load that’s moving in another direction. Be sure to maintain good mechanical position throughout.
Bob LeFavi is a professor of sports medicine at Armstrong State University in Georgia and co-owner of CrossFit GroundSpeed. He also competed in the 2013 Reebok CrossFit Games, Masters division.
This is a great exercise to work eccentrically because it translates strength gained to so many other CrossFit movements — cleans, thrusters, wall balls and box jumps, just to name a few. While partner-assisted and accentuated-eccentric training work well with front squats, we suggest adding eccentric-only work to your front-squat regimen.
After warming up, increase to a load that is at least 115 percent of your front-squat maximum. Most experienced lifters who focus on eccentric training would not hesitate to go to 140 percent of maximum, but do not start there.
Position yourself under the bar situated in a rack. Grasp the bar in a front-rack position. The step back is critical because for very brief periods during the walk, you’re on one leg. In fact, the walk away from the rack may be the most difficult part of the movement for some. Try to keep the walk to one step with each leg.
Descend slowly and under control, inhaling on the way down. Focus on your quadriceps taking the load, always ensuring that your heels are flat and torso upright. When you get to your bottom position, dump the bar quickly in front of you.
Many athletes were first introduced to “negatives” with standard bench presses. Sure, CrossFit HQ has been programming bench presses more and more, but while the exercise per se will likely never be a CrossFit standard, the movement translates to push-ups, burpees, planks, handstand push-ups and any overhead exercise.
Negatives on bench presses are best performed partner-assisted. Be very careful with these, particularly when using a barbell. The bar forces your shoulder joint into a specific position, and suddenly loading that joint can be dangerous; the shoulder joint was simply not designed to endure high impact in the bench-press position. Your partner should allow you to engage the weight gradually. In addition, your partner should be positioned at your head and have a reverse grip on the bar in barbell bench presses. With dumbbell presses, your partner should lift the weight at your wrists, not your elbows. Two to three sets of four to six reps is more than adequate for this high-intensity movement.
Eccentric training for pull-ups and ring dips can be performed by using the eccentric-only and accentuated-eccentric methods. Both can be accomplished through weighted descents. There are two general ways to perform weighted descents in these exercises.
For an athlete who does not have the strength to perform a pull-up (strict, kipping or butterfly) or ring dip without assistance, simply using bodyweight in a jumping pull-up or ring dip is a very good method to bring in eccentric muscle work. To perform a jumping eccentric pull-up or ring dip, jump high enough so (a) in a pull-up, your chin clears the top of the bar, or (b) in a ring dip, you achieve the top lockout position. At that point, your task is to lower yourself as slowly as possible.
For an athlete who can perform pull-ups or ring dips, using weights from the top/lockout position is the best way to add eccentric training to these movements. We do not recommend jumping with weights. The additional weight can come by way of a loaded flak jacket, a weighted hip harness (which loads weight from a chain that dangles between the legs) or a dumbbell pinched between bent knees. The key is to start the movement from the top position and lower yourself as slowly as possible. With each set, try to slow the descent down to a maximum of four seconds. Be careful to not drop too quickly into a descent.
Eccentric training for overhead deltoid work can be accomplished with all three methods. To perform eccentric-only and/or accentuated-eccentric shoulder presses, use a rack with a loaded bar set 2 inches lower than your standing lockout position. Keeping a tight torso and elbows locked, step under the bar and carefully stand with it in an overhead position. Lower the bar, fighting it on the way down. You can use lower pins to rack the bar or dump it. In the next rep, descend even more slowly, again working to a four-second descent.
To do partner-assisted negatives, use the same racking technique, but following a slow descent, your partner helps you raise the bar back up by providing force to the bar. Having your partner assist by pressing on your elbows is a commonly used technique, but that position is less safe. It’s also important that your partner be positioned directly behind you and that he or she is strong enough to maintain force on the bar to the top of the movement. If that’s not the case, perform presses from a seated position in the rack. Be careful to gauge the load so that it’s possible for your partner to provide enough assistance to safely raise the weight.