EXERCISING for just three seconds a day is enough to build muscle, research suggests.
Scientists found a single bicep curl done three times a week significantly improved arm strength.
GettyThree seconds of exercise done three days a week could be enough to build muscle, scientists say[/caption]
The team at Edith Cowan University in Australia last year discovered that doing it five days a week made people stronger.
But their latest work looked at the minimum number of days required to reap the benefits.
The study, published in the European Journal of Applied Physiology, found three separate occasions was the sweet spot.
Co-author Professor Kazunori Nosaka, said: “Our previous work has shown regular, shorter exercise is more beneficial than one or two big training sessions in a week.
“Now, we have a clearer idea of where the tipping point is where you start to see meaningful benefits from such a minimal exercise.”
A total of 26 healthy adults participated in the study, which was carried out over a month.
Each did a single three-second bicep contraction using their dominant arm, either two days or three days a week.
This is similar to slowly lowering a heavy dumbbell, from a bent arm to a straight arm.
Those who performed the move twice weekly saw no significant changes.
But the three-day-a-week group saw a small but significant increase in concentric strength (2.5 per cent) and eccentric strength (3.9 per cent).
Eccentric (or muscle lengthening) movement occurs as you slowly lower your arm down towards your waist during a bicep curl.
Curling your arm back up to your shoulder is a concentric (or muscle shortening) movement.
“These new results suggest at least three days a week are required, at least for the single three-second eccentric contraction training,” Prof Nosaka said.
But he was keen to point out that five times a week provided the biggest boost, with a 10 per cent increase noted in both categories, as well as isometric strength (contraction without motion).
More work is needed to establish if the same applies to other workouts – though experts agree even a small amount of physical activity is good for our health.
Prof Nosaka, who worked alongside researchers from in collaboration with Niigata University of Health and Welfare in Japan, said: “If it is not possible to have 20 minutes a day for exercise, even five minutes a day makes a difference for fitness and health.
“Of course, more studies are needed to confirm this, but our recent studies show the importance of accumulating small amounts of exercise as frequently as possible in a week.
“It is important to note that even a very small amount of exercise can make a difference to our body, if it is performed regularly.”
Prof Nosaka, from Perth, added that the mini workouts could stave off weakness and frailty in old age.
“It can prevent muscle strength loss due to diseases, sedentary lifestyle and space flights,” he said.