How do you measure up in bed?

A MOBILE application to monitor sexual performance is giving a new meaning to "taking your cellphone to bed".

But experts warn that a "report card" on how many thrusts per minute you average, how long you go for, and exactly how loud it gets, could ruin relationships.

Spreadsheets, which costs about R30 to download, monitors sexual performance to provide statistical and historical feedback, including a record of the date and time of encounters.

According to its website, the application gathers data from the user's movements and audio levels from the bedroom through an accelerometer and microphone.

The application does not record or play back audio or video because it "would be creepy" but encourages sharing the data with "your doctor if you're trying to get pregnant, your nutritionist since you're burning calories and with your friends to let the facts speak for themselves".

Johannesburg clinical sexologist professor Elna McIntosh said keeping a track record of bedroom activity was "compulsive" and "extreme behaviour". Furthermore, it could lead to insecurities.

"In any relationship you will find one person wants something more than the other. So he or she is basically saying, 'You don't desire me enough so let's measure how much you desire me.' If both are into it, that's wonderful, but if you are not a willing participant, it gets worse because afterwards you will be analysed.

"This is becoming like a medical exercise. It's almost like doing an ECG on someone. Looking at how many thrusts, how many minutes. It sounds awful," she said.

McIntosh said there were already too many "measures" for lovers to live up to.

"The average penis is this big or the average couple has sex this many times a year. There is so much sensationalism around sexual performance because it's always about bigger and better.

"This application now takes it a step further. One could say, we have sex only three times a week and leave it at that but now it's giving you a print-out and a performance card," she explained.

"I think it will definitely lead to performance anxiety.

"On the plus side, it could be fun. Couples could say: 'Wow look how high your heart rate went' or 'We are really good at thrusting'. So monitoring can be fun but it's a matter of what you are going to do with the results," McIntosh said.

Port Elizabeth clinical sexologist Leandi Buys said the app could be a distraction: "A lot of people say they cannot have sex with a baby in the room. This could actually be the baby in the room and make it awkward. Any level of awkwardness immediately puts pressure on the relationship. Instead of tracking one's sex life, couples should talk to each other about what they want."