Small business owners regularly work 50-hour weeks and take fewer holidays than the legal minimum entitlement in the UK, according to a survey by Bank of Scotland Business Banking.
The research suggests entrepreneurs now work three hours a week more than they did this time last year and estimates the UK's 1.4m small businesses collectively put in 31.2m extra working weeks a year.
A quarter (26%) of entrepreneurs estimated they would have to work longer hours for the remainder of the year as a result of the current economic conditions.
But it appears putting in the hours really can pay off. The survey found that those whose average working week was significantly longer tended to experience higher levels of average growth.
The average working week for small firms growing at over 10% a year was 52.3 hours, whereas those owners whose companies grew at less than that generally put in around 46.5 hours.
Small businesses in Scotland were the most likely to work long hours, with an average working week of almost 52 hours, compared to entrepreneurs in the south-east who put in 47 hours a week.
Not surprisingly, though, working such long hours has an impact on entrepreneurs' personal life and stress levels, with the current challenging conditions also playing a part.
Seven out of 10 (71%) small business owners now say they felt stressed by running a business compared to 54% last year, while 24% said they would not be able to take a full week's holiday this year.
Entrepreneurs took an average of 15 days' holiday a year, the survey found, with 26% taking under 10.
"Given that the stakes are so high, it comes as no surprise that Britain's entrepreneurs are burning the midnight oil to try and make a success of their business," said Peter Wood, head of strategy and products at Bank of Scotland Business Banking.
"Unfortunately, however, there is a clear downside to the pursuit of success for some small business owners with increased stress levels.
"If we can create an environment for small business in Britain that helps small firms work smarter, by allowing them to get on with the job of running their business, then we will continue to see them grow and prosper."
