Are you familiar with the term “negative rep” or “negative training?” This form of training places emphasis on the negative, or eccentric, portion of an exercise. The reps that you do when you weight train or work with your own bodyweight consist of a concentric phase and an eccentric phase. The concentric phase is the phase where the muscle shortens or contracts against a resistance or against gravity whereas the eccentric phase is when you lengthen the muscle against resistance.
For example, when you do a push-up, the concentric portion is when you push your body away from the mat. In this case, your triceps and deltoids are working against gravity to lift your body up. For biceps curls, it’s when you bring the weights up toward your chest. In contrast, the eccentric, or negative phase, is when a muscle lengthens against resistance. With the push-up, it’s the lowering phase when you bring your body back toward the mat as you try to resist gravity and descend in a controlled manner. For biceps curls, you work eccentrically, or negatively, when you lower the weight back to the starting position while maintaining control. Likewise, the concentric portion of a squat is when you lower your body toward the floor and the eccentric, or negative, is when you return to the starting position.
Negatives or Eccentrics Create More Stress & Muscle Damage
Negative training places more focus on the eccentric phase of an exercise. Why would you want to do this? Studies show that during the eccentric phase of a movement muscle fibers sustain the most damage. In turn, this damage sparks greater muscle protein synthesis for repair. In response, growth ensues. The downside is you will likely experience a significant degree of DOMS, or delayed-onset muscle soreness due to the extra stress your muscle fibers sustained. When a muscle contracts eccentrically, muscle fiber are forced to bear more stress and damage than during a concentric contraction. Training eccentrically, in moderation, is good for muscle growth and muscle strength gains but a negative in terms of how your muscles feel afterward.
There’s another way that negative training helps muscles grow stronger and increase in size. Your muscles can handle more weight during the eccentric phase of a movement. You might comfortably handle only 12 pounds in each hand doing biceps curls concentrically, yet you can easily work with 15 pounds per hand during the eccentric phase of the movement. So, you can use a heavier weight than you would normally be able to handle when you only do the eccentric portion of the movement. In fact, studies show you can support up to 30% more weight eccentrically than you can concentrically. Using a heavier weight could very well be the shock your muscles need to break out of a plateau.
Finally, emphasizing the negative, or eccentric, portion of a movement taxes your nervous system more and improves the capacity of your nervous system to recruit fast-twitch muscle fibers, the type of fibers that are optimized for strength and power. So, the benefits are occurring at the level of the muscle (greater muscle damage) and at the level of the nervous system.
Putting Negative Reps into Practice
One way to train eccentrically is to use a weight that’s heavier than your one-rep max (about 110% of one-rep max), since you can work with more weight eccentrically than concentrically. You can do this by having a spotter help you move the weight concentrically and you control the weight during the eccentric portion of the movement by slowing bringing the weight down. Another way is to use a weight that’s around 70 to 80% of your one-rep max. Lift the weight concentrically at your normal tempo and then lower the weight slowly, taking 4 or 5 seconds to reach the starting position. Doing this emphasizes the eccentric portion of the movement.
You can even use your own bodyweight to train negatively. If you’re still doing push-ups on your knees, get into a plank position with your hands on the floor. Slowly lower your body down to the mat. Since you’re stronger eccentrically, you can likely complete this phase of the push-up, even if you aren’t yet strong enough to push yourself back up. By working on the eccentric or negative phase of the push-up, you can build up strength and work toward doing a full push-up.
You can also train negatively using machines. For example, on a bench press machine, you can use two hands to push the weight up (the concentric phase) and one hand to lower it. (the eccentric phase) Using this method, you’re overloading one side eccentrically and forcing it to work harder than it’s accustomed to.
Another approach is to slow the eccentric phase of an exercise, so you’re keeping the muscle under tension longer during the eccentric phase. For example, do the eccentric phase in 5 seconds rather than 3. In this case, you’re increasing the eccentric volume that you do, by increasing the time under tension, without overloading the muscle. However, you’ll get the most benefits by actually overloading the muscle during the eccentric phase rather than just increasing the volume.
Be Judicious about Negative Training
Although negative reps can spur greater growth and strength gains, it’s demanding on your muscles and your nervous system. If you’re doing three sets of an exercise, you only need to do negatives on one of those sets and not for every exercise. A few negative reps per routine is usually enough. Also, don’t train negatively more than once per week to avoid exhausting your muscles. It’s easy to overdo negative training and this can actually end up limiting your growth since your muscles don’t have enough time to recover and repair.
The Bottom Line
Negative reps, used judiciously, are an effective strategy for building strength and muscle size and for breaking through or avoiding a plateau. Take advantage of the additional opportunity for growth that they offer.
Journal of Strength and Conditioning Research. 2015 APR 2015;29(4):1027-32.
J Physiol. 2001 Dec 1; 537(Pt 2): 333–345.doi: 10.1111/j.1469-7793.2001.00333.x