A new study has shown that slowly lowering weights strengthens and builds muscles as well as lifting and lowering them as with a typical rep.
This means that, for example, you could use two hands in order to lift a dumbbell and one hand to lower it slowly. However, this would not compromise the results. Japanese researchers believe that focusing on the lowering, or the “eccentric contraction”, can make a gym session more efficient.
The study published in the European Journal of Applied Physiology divided people into three groups of 14, for a five-week, twice weekly comparison.
One group did dumbbell curls, from full extension to approximately one-quarter of their maximum, for two seconds up and two seconds down in three sets. The researcher reset the weight after each rep. A further 14 people did the lifting portion and the remaining 14 only the lowering.
The lifters who both lifted and decreased the weights had an 18% increase in maximum strength and 11% increase in thickness.
People who lifted only the weights almost matched it, increasing their maximum strength by 14% and their muscle size by 10%. While the lifting-only group saw an increase in their max force of 11%, it was not enough to make a significant difference in muscle size.
Two ways your muscle fibers work are possible. Your biceps muscle uses a “concentric contraction” when you lift a dumbbell with a straight arm to your shoulder. The “eccentric” contraction is when the dumbbell is lowered back down by the biceps muscle.
The lifting-plus-lowering group saw the biggest gains because they were pretty much doing twice the number of reps. Similar gains in strength and muscle were made by the lowering-only group, but with half the effort.
Masatoshi Nakamura, PhD, a Japanese professor at Nishikyushu University, believes eccentric muscle contractions cause greater neurological adaptations in your spine and brain than concentric. Your nerves send more “pull harder” signals to your muscles, in other words.
The spring action of a protein called “titin”, in muscle fibers, produces more force during eccentric contractions, while using less energy. This is why hypertrophy, or an increase in muscle size, could be caused by titin.
Nakamura states that muscle hypertrophy could be explained by the presence of vitamins in muscle fibers. We believe other factors, like neurological adaptations, play a significant role in increasing muscle strength.
A key factor was the short range of motion in dumbbell curls. A 2019 study published in the Journal of Strength and Conditioning Research found that exercising with triceps exercises in a partial range of motion produced more muscle growth than full-range-of-motion movements.
Although dumbbell curls were not performed in the latest study, Nakamura said that it was similar to other muscle exercises.
Nakamura recommends using a heavier weight for single-arm dumbbell curls. Your muscles are stronger when you lower than they are when you lift. To raise the dumbbell to 50 degrees, use both your arms. Then lower it slowly over a two-second count. You can ask a spotter for help with two-handed bent- and straight-bar curls.
The same technique can be used with leg curls or leg extension machines. Two legs are used to lift the weight, and one leg is used to lower it.
Your gym may soon have more equipment designed to lower your movements.
Nakamura states that “Other machines which can emphasize eccentric contraction” are being developed.
This post was written by Darryl Johnson, Co-Owner of Apex performance. At Apex performance we are a community of highly trained experts looking to provide performance enhancement and a permanent lifestyle change for our clients in a fun and interactive environment. Members can take advantage of one-on-one training, small group classes and specialized courses for a wide variety of athletics, sports training and body goals! Click Here to learn more!