London: Half of people find it hard to motivate themselves to leave the house to have fun after a hard day at the office, a survey has found. A third of participants involved in the Weight Watchers study confessed to turning down a night out with friends or family because the effort of getting ready was simply too much.

And almost a fifth said they were too exhausted for romance with their partner at the end of the day, a daily reported. The study of 2,638 adults found that lack of time, long working hours and being too busy were the key reasons for the sedentary lifestyles.

Participants also revealed that their friendships were suffering due to their lack of vim, because they were choosing to text loved-ones rather than make the effort to call them.

According to the findings, the average person does nothing but sit down for an average of four nights a week, and a fifth of us do absolutely no exercise on any night of the week.

Some 21 per cent put their lack of exercise down to being busy balancing work and family life, while 32 per cent claimed they are just too exhausted after a day at work.

"Lack of time is a commonly stated barrier to doing more, or any, physical activity," said Stuart Biddle, a professor of physical activity at Loughborough University.

"However, researchers have stated that this is more a perception than reality. It is more to do with motivation and priorities than lack of real time," he added.

Zoe Hellman, head of public health at Weight Watchers, said that our lack of motivation could also put our health at risk. "According to our research, more than 14million adults are leading more inactive lifestyles than is healthy. The lack of motivation is putting people at risk of health issues later in life, including obesity and type-2 diabetes," she stated.