While finding the time or motivation to exercise regularly can be tricky, a new study shows that a simple dumbbell exercise can lead to a significant improvement in strength, even when done for just three seconds a week. day.
A significant gain in strength
Published in the Scandinavian Journal of Medicine and Science in Sports, this surprising work was carried out by Australian and Japanese scientists on a group of 52 healthy students. Thirty-nine of the subjects were required to perform a 3-second maximal voluntary contraction (MVC) of the biceps five times per week over a one-month period, while the other 13, who made up the control group, were required to perform no exercise. during this same period.
Three types of dumbbell contractions were performed: typical concentric (muscle shortening), eccentric (muscle lengthening), and isometric (muscle keeping still). The researchers measured the maximum voluntary contraction strength of the subjects’ muscles before and after the four-week period, which allowed them to highlight surprising changes.
The eccentric CVM group had the best results, with significant improvements in concentric (12.8%), isometric (10.2%) and eccentric (12.2%) strength, and an increase in overall 11.5%. While the benefits were less significant, members of the concentric CVM group saw a 6.3% increase in isometric strength while those in the isometric CVM group showed a 7.2% improvement in eccentric strength.
According to the researchers, the weaker improvements seen in the latter two groups suggest that eccentric contractions may be the best way to gain strength when the time that can be devoted to training is limited.
Prevent loss of muscle mass and strength associated with aging
Although the mechanisms underlying the powerful effects of eccentric contraction remain somewhat obscure for now, the fact that a single maximum contraction of three seconds per day significantly improves muscle strength over a relatively short period of time has important implications. implications for the prevention of age-related loss of muscle mass and strength.
If the same effects can be replicated for other muscle groups, this could lead to a particularly effective way to engage the whole body.
« We haven’t studied other muscles yet, but if we find that the three-second rule also applies, it may be possible to create a complete exercise that can be done in less than 30 seconds. “, conclude the authors of the study.