Does heavier eccentric resistance
build more strength?

One press. Two resistance settings.

On our homepage, a client presses a handle away from a single Beyond Power VOLTRA I. The animation’s display shows 20.0 lb as the client presses the handle away from their chest and 28.5 lb as they guide it back toward their chest. For the home-training service I’m preparing in Cary, that ability to set different resistance for the two parts of a repetition is one of the device’s interesting features.

In that press, the working chest and arm muscles shorten as you push the handle away. That’s the concentric phase. As you guide the handle back toward your chest, those muscles lengthen while resisting the cable’s pull. That’s the eccentric phase. Both are active parts of the exercise. In a biceps curl, the eccentric phase is lowering the handle. The direction depends on the exercise; muscle lengthening under tension is what defines it.

This is a documented VOLTRA feature. Beyond Power’s eccentric adjustment adds resistance during the eccentric phase while keeping the base resistance for the concentric phase. It is an adjustment within Weight Training mode. Using a greater load in the eccentric phase is called accentuated eccentric loading.

Here we’re comparing the resistance in two phases of a repetition. Changing resistance with cable extension within a phase, or moving more slowly, are separate choices. The question in this article is whether extra eccentric resistance earns its place in your training.

The featured paper

A promising idea. A comparison worth reading carefully.

A 2016 study by Walker and colleagues compared ten weeks of traditional lower-body training with a program using 40% more resistance during the eccentric phase. Twenty-eight strength-trained young men completed the study: ten in each supervised group and eight continuing their usual training.

The eccentric-strength test improved significantly within the accentuated-eccentric group only, but its group-by-time interaction was not significant. An improvement being statistically clear in one group and unclear in another does not, by itself, establish that the groups improved differently.

As a statistician, I care about which comparison supports a claim. This small leg-training study gives me a reason to consider the method, not proof that it beats ordinary loading for everyone. It did not test VOLTRA training in clients’ homes.

First, a movement you can control.

I wouldn’t begin by copying the animation’s numbers. We’d first find a suitable mount and position, then learn a controlled repetition with a manageable setting. A stable setup matters in both phases. If balance or positioning is limiting the exercise, adding eccentric resistance would not be my next step.

Once the movement is familiar, I could introduce a modest increase in eccentric resistance if it fits your goals and ability. I’d watch whether you can maintain the intended range and control, and ask how the set feels. I’d also ask about soreness and recovery before the next session. If the change makes the exercise harder to manage without a useful benefit, we can reduce it or return to the same setting in both phases.

This is part of the appeal of bringing digital resistance to your home: I can adjust those settings while coaching you. It gives us another option to evaluate. It does not make every option necessary, and you can build a demanding program without using every mode on the screen.

Record both sides of the repetition.

If I write down only “20 lb,” I’ve left out something important about a set with extra eccentric resistance. I’d record both resistance settings alongside the exercise, side, repetitions, setup, and your reported effort. I’d also note changes in range or tempo that make one session harder to compare with another.

Then I’d look for a useful pattern across sessions: are you completing the planned work with control, progressing on a repeatable exercise, and recovering well enough for your next appointment? We’d review those records together and decide whether to keep, adjust, or remove the extra eccentric resistance.

Your training log would help us make decisions. It would not turn a before-and-after improvement into proof that this particular feature caused it. Practice, consistency, other exercise, and recovery can change at the same time. Keeping comparisons reasonably consistent is how my statistical background can make the records more useful.

The reason I’d use extra eccentric resistance is that it serves your program. The reason I’d keep it is that the work remains manageable and the progress is worth continuing. That’s the judgment I want to bring with the equipment.