Feeling lighter now that you have been gymming for a week? Convinced the pounds have started melting, improving your looks? It's all in your mind.

It's the exercise and not higher levels of fitness that is improving your body image, says a study by Heather Hausenblas, an exercise psychologist from the University of Florida, and her student Anna Campbell. After analysing 57 studies to see how physical activity impacts an individual's body image, they found even if exercise didn't improve fitness levels, it did make people feel better about themselves.

What's more, it wasn't how hard you exercises, or how much but just that you did.

One study showed no difference in body image improvement between people who exercised minimum 30 minutes a day, five days a week and those who didn't. "We would have thought that people exercising this amount would have felt better about their bodies than those who did not work out as much," Hausenblas said.

In another study, women were found to feel slightly better about their bodies than were men if they sweated it out. "We believed the gap would be much bigger, but what could be coming into play is the rise of body image issues among men. We're seeing more media portrayals of the ideal physique for men rather than the overriding emphasis on women we did in the past," Hausenblas said.

And the older you get, the better exercise impacts you psychologically perhaps because older people are more concerned about their bodies as physical activity among them is lower than younger people.

Low body image is becoming something of an epidemic across the world due to unrealistic images being flashed in the media. "Body dissatisfaction is a huge problem in our society and is related to all sorts of negative behaviour including yo-yo dieting, smoking, taking steroids and undergoing cosmetic surgery. It affects men and women and all ages, starting with kids who are as young as five years old saying they don't like how their bodies look," said Hausenblas. The analysis has been detailed in Journal of Health Psychology.

If you don't like what you see in the mirror, time to switch to the mirror in the gym. Mind matters.