In what will be welcome news to anyone struggling after eating too many pieces of Christmas cake, WA researchers have found an exercise short-cut.
An Edith Cowan University study found people who only lowered weights achieved the same improvements in muscle strength and size as those who lifted and lowered weights, despite performing half the amount of reps.
Lower rather than lift
This suggested the focus should be on lowering, rather than lifting, weights.
The team, which also included researchers from Niigata University and Nishi Kyushu University in Japan and Brazil’s Londrina State University, had groups of people perform three different types of dumbbell curl exercise and measured the results.
It found those who only lowered a weight saw the same improvements as those who raised and lowered weights — despite only performing half the number of repetitions.
ECU’s Professor Ken Nosaka said the results reinforced previous research indicating a focus on “eccentric” muscle contractions — in which activated muscles are lengthened — is more important to increasing strength and size of muscles, rather than the volume.
“We already know only one eccentric muscle contraction a day can increase muscle strength if it is performed five days a week — even if it’s only three seconds a day — but concentric (lifting a weight) or isometric muscle contraction (holding a weight) does not provide such an effect,” Professor Nosaka said.
“This latest study shows we can be far more efficient in the time we spend exercising and still see significant results by focusing on eccentric muscle contractions.
“In the case of a dumbbell curl, many people may believe the lifting action provides the most benefit, or at least some benefit, but we found concentric muscle contractions contributed little to the training effects.”
Crunching the numbers
The study consisted of three groups who performed dumbbell curls twice a week for five weeks, plus a control group who did nothing.
Of the training groups, one performed eccentric-only muscle contractions (lowering weight), another concentric-only muscle contractions, and another performed both concentric and eccentric muscle contractions (lifting and lowering weight alternatively).
All three saw improvements in concentric strength, but this was the only improvement for the concentric-only group.
The eccentric-only and concentric-eccentric groups also saw significant improvements in isometric (static) strength and eccentric strength.
Despite the eccentric-only group doing half as many reps as those lifting and lowering weights, the gains in strength were very similar and the eccentric-only group also saw a greater improvement in muscle thickness, an indicator of muscle hypertrophy: 7.2% compared to the concentric-eccentric group’s 5.4%.
“Understanding the benefits of eccentric-focused training can allow people to spend their time exercising more efficiently,” Professor Nosaka said.
“With the small amount of daily exercise needed to see results, people don’t necessarily even have to go to the gym — they can incorporate eccentric exercise into their everyday routine.”
Putting it into practice
Professor Nosaka recommends using a dumbbell with two hands to help with the concentric (lifting weight) phase, before using one arm for the eccentric phase (lowering weight), when performing bicep curls, overhead extensions, front raises and shoulder presses.
When using leg weight machines, Professor Nosaka recommends using the same concentric/eccentric technique when performing knee extensions, leg curls and calf raises.