From the teeth-gritting clench of a bicep curl to the dip of a squat, we tend to think of upwards movements as the most beneficial part of strength training.
The “lifting” motion in which our muscles shorten – known as concentric exercise – is important. But what happens on the way down, when we lower a weight and our muscles lengthen – known as eccentric exercise – can be just as beneficial, according to a new article published in the Journal of Sport and Health Science.
Professor Ken Nosaka, director of exercise and sports science at Edith Cowan University and the article’s author, has been researching eccentric exercise, which includes movements such as chair squats, wall sit-ups and walking downhill, for decades.
What is eccentric exercise and who is it for?
There are three different ways our muscles contract: concentrically (lifting), eccentrically (lowering) and isometrically (staying static). Many common exercises combine all three.
But Nosaka believes we often overlook this second type of movement. His research suggests can be just as beneficial as concentric movement for building strength and muscle size, as well as less fatiguing.
“Eccentric movement is a more powerful stimulus for muscles to get stronger,” he says.
This includes findings that the same strength gains can be achieved with half the reps if you lower instead of lift, while a 2023 study of his found even a single, three-second eccentric arm contraction each day can improve strength.
Given that eccentric exercises require less metabolic energy and oxygen to perform, Nosaka thinks they are particularly beneficial for older and/or sedentary adults.
However, Dr Lewis Ingram, a physiotherapy lecturer at the University of South Australia says purely focusing on just one component of exercise can be a little reductionist.
“I think that the general population should just do the whole exercise. Breaking the exercise down and just doing the eccentric component is a lot more work to do in terms of the feasibility of it,” he says.
A bicep curl, for example, needs to involve an upwards movement for it to be repeated.
But Nosaka says one way to focus on eccentric movement is with the “2:1 method”, which involves using both limbs to lift a weight, and just one to lower it.
He adds that this style of exercise can be just as beneficial for bone density.
“When you are doing eccentric contractions, the tendon is more stretched. The stretch signal is going to the bone, which is getting stronger,” he says. “When you are descending stairs, you have put more weight on one leg, right? So then that can increase bone mineral density.”
While Ingram points out many studies referenced in the paper don’t rely on robust enough evidence – small sample sizes, for example – he says it is important to slow down and focus on eccentric movement to build muscle (around three seconds, according to Nosaka).
He says solely focusing on eccentric movement can be beneficial for elite athletes, and exercises in which someone is not strong enough to perform an “upwards” concentric movement, such as a pull-up.
What muscle soreness after exercise means
Another common belief about exercise is “no pain, no gain”, the idea that muscle soreness correlates to effort and results.
“Eccentric contraction can cause muscle soreness, especially the first time you do it or after a long time without exercising,” says Nosaka.
“But the important thing is that muscle damage or muscle soreness is not necessary if you want to get strong or get a bigger muscle size.”
To prevent the muscle soreness that can come from eccentric exercise, he recommends performing fewer reps at lower loads to start with.
However, hypertrophy or skeletal muscle building does require increasing load over time, says Nosaka.
Ingram agrees that soreness is generally most attributed to eccentric contractions, but is not necessarily an indicator of a good workout, and tends to dissipate with repetition over time.
Keep it simple
One of Nosaka’s favourite eccentric exercises is one we do daily.
“We normally sit down on the chair maybe 20 times a day – at mealtimes, for example, and when you watch TV or you go to the toilet. So whenever you sit down, try to lower yourself more slowly,” he says.
Ultimately, Ingram says the general population should just keep it simple, particularly given most adults fail to meet benchmarks for physical activity.
He says most people should aim to follow the World Health Organisation’s guidelines, which recommend 150 minutes of moderate-intensity physical activity or at least 75 minutes of vigorous-intensity physical activity throughout the week, and at least two strength training sessions per week.
“If we can just get people to do the basics right, then that’s a lot more effective.”
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