Eccentric (lowering phase)

Eccentric: what is it?

Every rep has three parts: the muscle lengthens (eccentric), holds (isometric) and shortens (concentric). The eccentric is the one most lifters rush through, because gravity does the work for you if you let it. Controlling it changes the stimulus of the exercise, and it is the phase most tied to muscle damage, soreness and tendon adaptation. Coaches control it with tempo prescriptions and, for advanced clients, with methods that load the eccentric more than the concentric.

Why the eccentric matters

A muscle can resist more load while lengthening than it can produce while shortening. That is why a client who cannot press a weight up can still lower it slowly with control, and why a spotter can help on the way up and let the client own the way down. The eccentric is where most of the mechanical tension on the muscle fibers happens at high force, which is one reason it is associated with hypertrophy and with the strengthening of tendons.

The same property explains DOMS. The soreness a client feels one to two days after a new exercise comes mainly from the eccentric portion: downhill running, the lowering of a Romanian deadlift, the slow negative of a pull-up. A session built purely on concentric work (sled pushes, for example) produces much less soreness even at high effort.

Prescribing the eccentric with tempo

The standard way to control the eccentric is a four-digit tempo code. The first digit is the eccentric, in seconds. A "3010" back squat means a 3-second descent, no pause at the bottom, a 1-second ascent and no pause at the top. Slowing the eccentric increases time under tension per rep and forces the client to use less weight, which is often the goal with a beginner learning to own the movement.

Eccentric overload methods

Because the eccentric can handle more load than the concentric, advanced clients can be loaded beyond their concentric maximum on the way down. Common methods include two-up, one-down (lift with both limbs, lower with one on a leg press or leg curl), assisted negatives (a spotter helps the concentric, the client controls the eccentric alone), and weight releasers or bands that add load only on the descent.

These methods create a lot of muscle damage. They belong at the end of a training block, in low volume, and never for a client who is new to the exercise or still sore from the previous session.

• Two-up, one-down on machines (leg press, leg curl, leg extension).
• Negative-only reps on pull-ups or dips for clients who cannot yet do a full rep.
• Slow negatives (4 to 6 seconds) as a finisher on isolation exercises.
• Supramaximal eccentrics with a spotter, reserved for experienced lifters.

Common mistakes

The first is dropping the weight. A client who lets the bar fall on a bench press or bounces out of the bottom of a squat is skipping the eccentric entirely, and usually also the part of the range where the muscle is most stretched. The second is the opposite: making every eccentric painfully slow. A 5-second negative on every set of every exercise reduces the load so much that strength progress stalls. Use slow eccentrics as a tool, and keep most working sets at a controlled 2 to 3 seconds.