Working with researchers from the Universities of Niigata and West Kyushu in Japan and Londrina State University in Brazil, the ECU team recruited three groups of people to perform different types of dumbbell curls twice a week for five weeks.
One set performs concentric contractions (lifting weights) and eccentric contractions (lowering weights). Another group focused on concentric contractions only, and a third group performed eccentric contractions only. An inactive group served as a control group.
It's better to lose weight than to lift weights
The results showed that those who only lowered the weight saw the same muscle improvement as participants who both raised and lowered the weight — despite only doing half the number of repetitions. Even more interesting, the eccentric-only group had a 7.2% increase in muscle thickness, compared to a 5.4% increase in the concentric-eccentric group.
ECU's Professor Ken Nosaka explained that these findings suggest that focusing on “eccentric” muscle contractions (i.e. activated muscles lengthen) is more important in increasing muscle strength and size than increasing muscle volume.
“We already know that if you perform just one eccentric muscle contraction per day, five days a week, you can increase muscle strength — even if it's only 3 seconds per day — but concentric muscle contractions (lifting weights) or isometric muscle contractions (lifting weights) don't. may not provide such an effect,” said study author Professor Ken Nosaka.
“This latest research shows that by focusing on eccentric muscle contractions, we can spend our time exercising more effectively and still see significant results. benefit or at least some benefit, but we found that concentric muscle contraction contributed little to the training effect.”
