Most of us will have put off going to the gym at some point in our lives (let's be honest, probably on more than one occasion).
But a poll has found two in five British women postpone their gym workout because they do not feel fit enough.
A new survey also found that 33% of women do not want to go to the gym because they feel intimidated by other fitter or more competitive people.
A third are embarrassed what people will think of them when they exercise and 27% said they felt put off because they do not know how to use gym machines, according to the British Heart Foundation survey.
The charity polled 2,000 adults from across the UK as part of its new MyMarathon challenge. Over the month of May, people are being encouraged to run 26.2 miles - yep, that's what London Marathon runners did in a day - while helping to raise money for heart research.
Lucy Wilkinson, senior cardiac nurse at the British Heart Foundation, said: "Keeping active is vital to help improve your heart health, so it is concerning that what's putting so many women off exercise is a fear of being judged about how they look and their level of fitness, and feeling self-conscious around others when exercising. Women should feel proud to exercise knowing they are helping to keep their hearts strong.
"And now with the MyMarathon challenge you don't have to be a slave to the gym. You decide the pace and you decide the place, so it's a great way to get active without feeling intimidated, and help us beat heart disease."
To find out more visit mymarathon.bhf.org.uk