The Science of Negative Reps and How They Benefit Your Fitness

negative reps

Muscles eventually adapt to the stimulus you place on them. In the beginning, muscles grow and become stronger quickly as conventional training places a stimulus on them that they aren’t accustomed to. As you gradually increase the challenge by using progressive overload, you find yourself becoming stronger and the size of your muscles increases. But after months of training, you may eventually reach a plateau and need to stimulate the muscle differently. That’s where negatives come in.

The Components of a Rep

When you do a repetition using a weight or your own body weight, the rep consists of two phases: the concentric and the eccentric phase. With conventional training, you probably think more about the concentric portion of the movement. The concentric phase is where you actively contract the muscle, usually while holding a weight. For example, with a chest press, the concentric phase is where you push the weight away from your body. In contrast, the eccentric or negative is the portion of an exercise where the muscles lengthen. For a chest press, it’s when you lower the weight back to your chest. This even applies when you run or walk. Running or walking downhill is an eccentrically focused movement while walking or running uphill emphasizes the concentric.

Most people think the concentric phase contributes the most to muscle gains, but research shows that a hefty amount of muscle damage occurs during the eccentric phase of a movement. How could that be? You’re actively contracting the muscle during the concentric portion of the movement, but your muscles still work during the eccentric phase. The muscle or muscles have to “brake” to control the rate at which the muscles lengthen. Not only are the muscles still contracting and generating force during the lengthening phase, but the muscle is getting hit even harder with damage. Research shows the sarcomeres, the component of the muscle that houses the filaments that slide past one another when the muscle contracts, are disrupted more by eccentric muscle contractions than concentric ones.

Muscle Damage Must Be Repaired

Once disrupted, the muscle damage needs to be repaired. Therefore, satellite cells and anabolic signaling molecules initiate a coordinated symphony of changes that bring about muscle protein synthesis. As muscle cells build new muscle proteins, the damage is repaired, and the muscle fibers increase in size. The increased potential for muscle damage means more robust repair and, hopefully, greater muscle growth.

The downside to eccentric contractions is that they lead to greater muscle soreness. After a workout that emphasizes eccentric or negative reps, you can count on feeling sore and stiff for a few days. Studies show that the damage to the sarcomeres is so severe that some muscle fibers actually die. The muscle also becomes swollen and loses some of its ability to generate force. This explains why muscles feel so stiff and why you can’t lift as much weight for a few days after negative training. It’s delayed onset muscle soreness at its finest! It’s also why muscles need longer to rest and recover after eccentric or negative training.

Why Would You Want to Do Negative Training?

Since emphasizing the negative leads to more muscle damage and muscle soreness, why would you want to do them? The increase in muscle damage stimulates muscle repair and growth, especially if you’re stuck in a plateau. In addition, research shows that we can generate between 20% and 30% more force during the eccentric phase of a muscle contraction relative to the concentric phase. Therefore, you can handle more resistance during the eccentric phase and that boosts muscle hypertrophy.

Another reason to do negative training is that doing so may reduce the risk of injury. Research shows that eccentric training lowers the risk of repeat hamstring injuries after athletes have already suffered from one. One study carried out on professional and amateur soccer players found that eccentric training reduced the risk of new and recurring hamstring injuries. Physical therapists even use eccentric training to rehabilitate and strengthen muscles after a sports injury. One study even found that eccentric training was equally effective as surgery for training athletes with patellar tendinopathy. Studies show that it increases tendon stiffness so that the tendon is less prone toward injury.

How to Do Negative Reps

There are several ways you can approach negative training. If you have a partner, you can work with a weight that’s heavier than what you normally lift. Your partner helps you complete the concentric phase of the movement and you do the eccentric portion on your own. This works because you can manage more weight eccentrically than you can concentrically.

An even simpler way to get the benefits of eccentric or negative training is to do exercises, like curls, at a slower tempo, especially during the eccentric phase. When you do biceps curls, bring the weights back to the starting position slower than normal. Use a tempo 3-0-6 where you concentrically contract the weight at the normal tempo but take twice as long to complete the eccentric phase. The key is to prolong the time the muscles are under tension during the lengthening phase.

Add an eccentric twist to push-ups. When performing a push-up, lower your chest to the ground at the usual rate, around 8-10 seconds. Once you reach the bottom, push yourself back up as quickly as possible, similar to a plyo push-up. You can adapt a variety of exercises to emphasize the negative more.

Be Judicious with Eccentric Training

Since negative reps cause more muscle damage, your muscles need more time to repair after an eccentric training session. So, don’t do them too often. Once a week is enough to offer benefits yet still give your muscles enough time to recover. Start by doing only a few eccentric reps, possibly by including a set at the end of your workout. Add more as you become stronger but keep the time you devote to negative reps limited due to the taxing nature of this type of training. But keep eccentric training in your back pocket as a way to help you break out of a plateau.



·        J Physiol. 2001 Dec 1; 537(Pt 2): 333–345.

·        American Journal of Sports Medicine 39(11): 2296-303 (201100

·        Exercise and Sport Sciences Reviews: April 2005 – Volume 33 – Issue 2 – p 98-104.


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Accentuated Eccentric Lifting: a Different Approach to Conquering Strength-Training Plateaus

Strength Training: What Is an Eccentric Contraction?

Is Eccentric Exercise a Metabolism Booster?

How Often Should You Change Your Strength Training Routine?


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