It's one of those bittersweet truths in life - the frantic sexual desire that comes with a new relationship tends to fade with time, so how can we keep the flame going? One theory offers up an extreme, if a little odd, solution: sex without orgasm.

Dr Alice Bunker Stockham, a Chicago feminist and obstetrician in the late 1800s, invented a novel way to strengthen marriages by encouraging men and women to avoid orgasm, focusing instead on the lovemaking itself. She coined the theory "Karezza" after the Italian word for "carezza" which means "to caress".

In a recently published book entitled Cupid's Poison Arrow author Marnia L. Robinson takes a fresh look at Karezza as a way for couples in long term relationships to connect without the pressure of orgasm. She believes that the high expectations that come with orgasm can ultimately be damaging to a relationship.

"Such feelings, although perfectly natural, can create projections and resentment that cause disharmony, especially after our temporary honeymoon neurochemistry wears off," she writes.

A combination of society and age-old knowledge suggests that long term relationships are in fact beneficial to our health which means that we tend to have monogamous relationships even when our instinctual mating drives might have us feel otherwise.

This mating drive is programmed to heighten at the beginning of the chase, and to slowly wear off as time moves on, which means we experience steadily less passionate lovemaking over time.

The trick is to by-pass this "mammalian mating system" by focusing on what Robinson calls a "relaxed union".

She believes that the theory is rooted in neuroscience. "Orgasm really isn't in our genitals, but actually between our ears," she argues.

"The brain in love triggers neurochemical reactions for infatuation, lust and attachment. Too often, however, those phases are followed by boredom, irritability, heartache, the urge to self-medicate with drugs or alcohol - and attraction to new potential mates," reads the succinct blurb of her recently published book Cupids poison arrow.

Research shows that dopamine levels peak straight after orgasm - similarly to the way it does when we shoot up with heroine. But if the "orgasmic high" has such a close physiological similarity to when we take heroine, then so too must the come down which results in a neurochemical "hangover". Men typically experience this come down immediately after sex, while women's chemistry is affected for as long as two to three weeks after an orgasm.

Moreover, overstimulation can result in a desensitisation of the brain to the usual sources of pleasure. This can result in disappointment felt by the pleasure seeker and a feeling of being ineffective felt by the pleasure giver.

Robinson believes that Karezza offers up a simple and effective solution because lovemaking is a continual experience that is never "finished off" like a normal lovemaking session would be at orgasm.

Not only does the method encourage continual sexual energy to flow, it also helps to promote oxytocin production - known as the cuddle hormone for its association with bonding.

Practitioners of the method say that it has given them a new hope in their relationship. In fact, unusually many men advocate Karezza's unique way of encouraging an increase in sexual energy, prevention of boredom in the bedroom and of course, a way to continuously bond with your long term partner.

Robinson recommends couples try the method over a month to see how it impacts their sex lives. She believes the results speak for themselves.

"They wake up every single morning and they are not even thinking about genital stimulation. They are snuggling, holding and breathing with eye contact and flow. It's very conscious - from the genitals to the heart."

Read Marnia Robinson's book Cupid's poison arrow to learn more.