At least three days of exercise a week is required to stay fit but if you could stretch it to five days a week, it would be optimum for your health, according to a study.

The findings showed that having the willpower to put in a couple of extra days of exercise per week will produce better results.

The study can help to further improve the understanding of how the human body responds to exercise.

"Our previous work has shown regular, shorter exercise is more beneficial than one or two big training sessions in a week,” said study lead professor Ken Nosaka from Edith Cowan University (ECU) in Western Australia.

"Now we have a clearer idea of where the tipping point is where you start to see meaningful benefits from such a minimal exercise," Nosaka said.

The study, published in the European Journal of Applied Physiology, saw participants perform a single three-second, maximum-effort eccentric bicep contraction similar to slowly lowering a heavy dumbbell, from a bent arm to
a straight arm.

Participants in the new study were split into two groups, with the first group performing a single three-second contraction two days per week, and the other performing the same exercise on three days per week.

After four weeks, researchers compared the participants’ bicep strength.

Those who performed the exercise two-days per week saw no significant changes; however the three-day group saw small but significant increases in concentric strength (2.5 per cent) and eccentric strength (3.9 per cent).

However, when performed daily for five days a week for 4 weeks it significantly improved muscle strength.