If you would like to start a strength-training program but don’t believe you have enough time, you may have to re-think that conclusion based on a newly completed study. Researchers from Australia and Japan found significant strength gains can be made with just three seconds of exercise per day.
It might sound too good to be true, but study participants saw their strength increase as much as 13 percent with just one repetition of the bicep curl five days a week for four weeks. Obviously, that’s just one muscle group, but the amount of time added up to just 60 seconds in a month.
Researchers at Edith Cowan University in Australia partnered with researchers from Niigata University of Health and Welfare in Japan to work with 39 healthy university students. They performed one muscle contraction at maximum effort for three seconds per day. They did this five days per week for four weeks.
"The study results suggest that a very small amount of exercise stimulus—even 60 seconds in four weeks—can increase muscle strength," ECU professor Ken Nosaka said. "Many people think you have to spend a lot of time exercising, but it's not the case. Short, good quality exercise can still be good for your body and every muscle contraction counts."
The students performed either an isometric, concentric or eccentric bicep curl. A bicep curl is done with one arm starting at the person’s side and involves lifting a weight up toward the chest with a bend in the elbow. The isometric group held the weight in a stationary position halfway up toward the chest, while the concentric group lifted the weight all the way up. The eccentric group started with the weight in the upper most position and controlled the weight as it went back down to the student’s side.
There was another group of students who performed no exercises during those four weeks. All students had their maximum voluntary contraction strength measured before and after the four-week timeframe. They were measured for isometric, concentric and eccentric strength.
The eccentric exercise group had the biggest gains in strength with an average overall increase of 11.5 percent. Their concentric strength increased 12.8 percent, while their eccentric strength increased 12.2 percent and their isometric strength increased 10.2 percent.
The concentric group only saw an increase in isometric strength (6.3 percent), while the isometric group only saw an increase in eccentric strength (7.2 percent). The non-exercise group saw no increase in strength.
"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," Professor Nosaka said. "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. Also, performing only one maximal contraction per day means you don't get sore afterwards."