Accentuated Eccentric Loading for Strength & Hypertrophy

What is Accentuated Eccentric Loading?

Accentuated eccentric loading (AEL) is an increasingly popular resistance training method that employs heavier loads during the eccentric phase of an exercise than the counterpart concentric phase.¹ AEL is based on the understanding that a muscle is able to exert more force (+20-50%) during a lengthening contraction than the coupled shortening contraction. In other words, it’s easier to lower a load than it is to lift it.

AEL takes advantage of eccentric strength by “overloading” the lowering phase of an exercise, effectively increasing muscle tension during stretch relative to conventional repetitions. For this reason and via mechanisms not fully elucidated in the literature, AEL is believed to enhance strength and hypertrophy.

Because AEL utilizes loads that often exceed concentric strength, exercise setup and execution can be challenging. Having a training partner, weight releasers or a digital resistance machine (e.g., Tonal, Gym Monster, or VOLTRA) available to assist with loading and unloading is a significant advantage, enabling the performance of many effective eccentric-focused exercises. When a partner or specialized machine isn’t available, being skilled in eccentric training techniques—such as the “2/1” technique²—and in manipulating external moment arms to adjust exercise difficulty during the eccentric and concentric phases is imperative for successful AEL execution. An external moment arm is the perpendicular distance between the line of action of an external force (e.g., the downward force of dumbbells due to gravity or the directional force of a cable) and the axis of rotation of the joint it acts upon. The greater the external moment arm, the harder the exercise becomes.

Applying AEL to the Abdominals

Just like exercises for the chest, back, arm, leg and gluteal muscles, AEL can be applied to abdominal exercises to promote strength and hypertrophy. To overload the paired rectus abdominis, a.k.a. the six-pack muscles, try “eccentric-only decline sit-ups” demonstrated in the video below. The concentric phase is bypassed by positioning the dumbbells closer to the legs (reducing the moment arm) and using momentum to cheat to the top of the sit-up. Once at the top position, the eccentric phase begins by flexing the spine, placing the dumbbells on the shoulders and actively unrolling to the bottom position before repeating the process.

To overload the obliques, try “eccentric-only trunk rotations” demonstrated in the next video. The concentric phase is avoided by pulling the cable into the upper abdomen (reducing the moment arm) at the end of each eccentric phase and pressing it back out to the start position of the next eccentric phase.

Incorporating AEL into a training program can potentially boost strength and hypertrophy while also providing exercise variety. As a general guideline, AEL can be performed as standalone sets or integrated at the end of conventional sets once target repetitions have been completed or concentric force is depleted in order to utilize any remaining eccentric force. When AEL is performed as standalone sets, eccentric load can be prescribed in excess of concentric load (e.g., 40 lbs. CON/60 lbs. ECC) or prescribed as “eccentrics-only” in the absence of a concentric load.

1. AEL is most often defined as a resistance training method that employs heavier loads during the eccentric phase of an exercise than the counterpart concentric phase; however, loads are not the only factor at play. The difficulty of an exercise is influenced by both loads (forces) and moment arms, which together produce torque—the rotational force around a joint. Therefore, it may be more accurate to say AEL employs greater torques during the eccentric phase of an exercise than the counterpart concentric phase. ↩︎
2. The 2/1 eccentric overload technique involves both limbs lifting a load concentrically and one limb returning the load eccentrically. ↩︎

References:

Hedayatpour, N., & Falla, D. (2015). Physiological and Neural Adaptations to Eccentric Exercise: Mechanisms and Considerations for Training. BioMed research international, 2015, 193741. https://doi.org/10.1155/2015/193741

Hessel, A. L., Lindstedt, S. L., & Nishikawa, K. C. (2017). Physiological Mechanisms of Eccentric Contraction and Its Applications: A Role for the Giant Titin Protein. Frontiers in physiology, 8, 70. https://doi.org/10.3389/fphys.2017.00070

Wagle JP, Taber CB, Cunanan AJ, Bingham GE, Carroll KM, DeWeese BH, Sato K, Stone MH. Accentuated Eccentric Loading for Training and Performance: A Review. Sports Med. 2017 Dec;47(12):2473-2495. doi: 10.1007/s40279-017-0755-6. PMID: 28681170.

Walker, S., Blazevich, A. J., Haff, G. G., Tufano, J. J., Newton, R. U., & Häkkinen, K. (2016). Greater Strength Gains after Training with Accentuated Eccentric than Traditional Isoinertial Loads in Already Strength-Trained Men. Frontiers in physiology, 7, 149. https://doi.org/10.3389/fphys.2016.00149