New York, July 27 (IANS): Having more action between the sheets may not make you happier. More sex can actually lead to low sexual desire in the long run, says a study.

In couples who were told to increase their frequency of sexual intercourse for a three-month period, researchers from Carnegie Mellon University in Pittsburgh found that it actually led to a decrease in sexual desire.

The desire to have sex decreases much more quickly than the enjoyment of sex once it has been initiated, the study observed.

"Instead of increasing the frequency, the couples should work on creating an environment that sparks their desire and makes the sex that they do have even more fun," said lead researcher and professor George Loewenstein.

For the results, the researchers recruited couples aged between 35 and 65 and assigned them into two groups for a three-month period.

One group received no instructions on their sexual frequency while the second group was told to double their frequency of sexual intercourse, home.bt.com reported.

The participants answered questions measuring their health behaviours, happiness levels and the occurrence, type and enjoyableness of sex. The couples in the second group reported lower sexual desire and a decrease in sexual enjoyment.

However, the researchers hope that the results can help couples improve their sex lives and raise their happiness levels. "Find the spark first and act later," they said.