Finding time to go the gym or even complete workouts at home can be a tricky task for busy folk, but a new study suggests even lifting a dumbbell once or twice a day can be worth your while, particularly when it comes to combating the effects of aging. The research examined the effects of different forms of bicep curls and found one in particular can lead to significant strength improvements, even when undertaken for just three seconds a day.
The research was carried out by scientists at Australia’s Edith Cowan University and Japan’s Niigata University of Health and Welfare, and involved a group of healthy university students. Thirty-nine of these subjects were made to perform a bicep curl at maximum effort for three seconds a day, five days a week, over a four-week timeframe, while another 13 students performed no exercise over the same period.
Subjects in the exercise group were made to complete one of three types of bicep curls, either a typical concentric curl where the dumbbell is raised toward the shoulders (shortening the muscle), an eccentric curl where it is slowly lowered back below the hips (lengthening the muscle), or an isometric curl where the arm holds it at a 90-degree angle (keeping the muscle stationary).
The researchers measured the maximum voluntary contraction strength of the subjects’ muscles both before and after the four-week period, which illustrated some surprising changes. The eccentric group enjoyed easily the best results, exhibiting significant improvements in their concentric strength (12.8 percent increase), isometric strength (10.2 percent) and eccentric strength (12.2 percent). Their overall muscle strength improved by 11.5 percent in total.
All exercising participants exhibited some improvement, with the concentric group improving their isometric strength by 6.3 percent, and the isometric group increasing their eccentric strength by 7.2 percent. These subjects saw no improvement elsewhere, however, indicating the eccentric contractions might be the best avenue to strength gains if time is limited.
“Although the mechanisms underpinning eccentric contraction’s potent effects are not clear yet, the fact only a three-second maximal eccentric contraction a day improves muscle strength in a relatively short period is important for health and fitness,” said Professor Ken Nosaka from Edith Cowan University.
The scientists say the findings could prove important when it comes to preventing the loss of muscle mass and strength associated with aging. They imagine if the same effects could be replicated in other muscle groups, it could lead to a particularly efficient way to work the entire body.
“We haven’t investigated other muscles yet, but if we find the three-second rule also applies to other muscles then you might be able to do a whole-body exercise in less than 30 seconds,” said Nosaka. “Also, performing only one maximal contraction per day means you don’t get sore afterwards.”
The research was published in the Scandinavian Journal of Medicine and Science in Sports.
3-second daily dumbbell workouts lead to significant gains in strength [New Atlas]