Most men worry their partner secretly fancies a more handsome friend. But recent research suggests competition from another male can increase a man’s production of testosterone.
And higher testosterone levels trigger arousal in women when they smell them in androstenol, a chemical called a pheromone secreted in men’s sweat.
In a study at the University of California in 2014, men viewed pictures of other men while next to their female partner as researchers took before and after blood samples to measure testosterone levels.
The results, published in the journal Hormonal Behaviour, showed testosterone increased when they perceived men as a potential sexual rival (because of their handsome features or athletic build), but changed little if they did not feel threatened.
This response was strongest when women were ovulating and most likely to be in the mood (men pick up clues to this through a subtle change in body odour and a slight increase in her voice pitch).
As Dr Arthur Cassidy, a psychologist who specialises in sex therapy, explains: ‘There is extensive research showing pheromones play a crucial role in attraction.’
In 2013, University of British Columbia researchers found women often wear red or pink when they are most fertile, similar to the way females in the animal kingdom display red or pink body parts to signal their fertility.
The researchers tracked 124 women through their menstrual cycles and found those at peak fertility — and, therefore, most likely to feel in the mood — are three times more likely to don a red top than those at low fertility.
Researchers at Glasgow University also found that women’s faces flush more during ovulation because high levels of the hormone oestradiol — which boosts fertility — also dilates blood vessels near the skin’s surface.
Ovulation starts roughly a week after the beginning of a woman’s period and this is when she is most likely to be receptive to sexual advances.
ANOTHER REASON TO HAVE AN APPLE A DAY
In case women need further motivation to get their five-a-day, one study suggests apples could work wonders for their libido.
A 2014 study at Santa Chiara Regional Hospital in Trento, Italy, found women eating apples daily had higher sex drives, increased arousal and more frequent orgasms than those rarely eating them.
The researchers said that chemicals called polyphenols — found in apples and most fruits — contribute to more oxygen-rich blood reaching the genitals during sex.
POTION THAT MAKES SEX LAST LONGER
One in four men in the UK has premature ejaculation, lasting an average of 1.8 minutes compared to the average of 7.3 minutes.
There is a prescription medicine, called Priligy, which can help by briefly raising levels of the feel-good brain chemical serotonin, delaying orgasm. But it costs £8 per tablet and is not available on the NHS.
A cheaper option is ‘delay’ creams which slightly numb the penis with a small dose of anaesthetic.
In a review published in the journal Sexual Health, researchers at Sheffield University looked at nine trials of delay creams and found they prolonged sex for longer than antidepressant drugs — like paroxetine — sometimes prescribed to postpone ejaculation by raising serotonin levels.
Delay cream can be bought over the counter (e.g., EMLA cream, from Superdrug, £20 for 5g tube).
SLASHING CALORIES FOR BETTER SEX
Restricting calorie intake slows ageing. But could it also boost your love life — even if you are already slim and healthy?
A study published in JAMA Internal Medicine found that healthy people enjoyed better sex if they cut daily calorie intake by a quarter, or to 1,500 calories for a woman.
Scientists at Pennington Biomedical Research Centre in Louisiana studied 218 adults, half of whom cut down on calories by 25 per cent while others stuck to a regular diet.
After two years, the calorie-restricted group had stronger sex drives while the rest reported no change.
However, there may be benefits to being on the cuddly side — a study in the International Journal Of Impotence Research found that overweight men are less likely to have premature ejaculation.
Researchers at Turkey’s Erciyes University found 14 per cent of normal weight men suffered premature ejaculation compared with six per cent of overweight or obese men.
The reasons are not clear and the study did contradict other research suggesting excess weight increases the risk of premature ejaculation; obesity also puts men in greater danger of erectile dysfunction.
One theory is that excess fat drives down the production of testosterone, low levels of which can delay ejaculation.
ELECTRICK SHOCK TO BOOST YOUR LOVE LIFE
It sounds unlikely, but zapping a tiny nerve in the ankle, using a technique called percutaneous tibial nerve stimulation, could improve a woman’s sex life.
It stimulates the tibial nerve with a mild electric current. This nerve is connected to muscles in the pelvis responsible for controlling a woman’s ability to orgasm.
The technique is used to treat overactive bladder in women.
But in a recent study at Careggi University Hospital in Florence, Italy, doctors tested it on 21 women with sexual dysfunction — defined as low desire, lack of arousal and inability to orgasm. After a single treatment, nine showed significant improvement, reported the Journal Of Sexual Medicine.
MEN NEED TO WORK THEIR PELVIC FLOOR
Pelvic floor exercises are best known for tackling urinary incontinence in women as a result of childbirth and ageing. But they could bolster men’s sex lives, too.
In 2015, researchers at the National Hospital of Denmark in Copenhagen studied 30 men with poor bladder control, as a result of a stroke, and taught half pelvic floor exercises to do daily.
After three months, the men’s scores on the International Index of Erectile Function — a one-to-five point system doctors use to measure impotence — went from five (the lowest) to three. Men who didn’t do the workouts stayed at five.
Physiotherapist Becky Aston, a specialist in women’s health, has seen increasing numbers of men seeking help. To do the exercises, men need to squeeze the muscles ‘as if they are trying to stop wind’.
‘Hold that for a few seconds at first but eventually you should aim for about 20 seconds. Do that ten times in a row, twice a day, for three to six months to strengthen the muscles and then every other day to keep them in shape.’
Meanwhile, women could benefit by working their own pelvic floor muscles through Pilates or yoga. A study in the Journal Of Sex And Marital Therapy found weekly classes improved libido and orgasms in healthy women aged 20 to 50.
Turkish researchers reported that after three months, women’s scores on a sexual function questionnaire (examining everything from desire to orgasm frequency) rose from an average 25.9 points to 32.2 — anything under 26.66 is ‘poor’.
Other studies have found yoga has similar benefits, probably because, as well as working the pelvic floor, both forms of exercise improve cardiovascular fitness, increasing blood flow to the genitals.
KEEN RUNNERS HAVE A HIGH SEX DRIVE
If a woman wants a man to satisfy her sexually and father her children, she should pick a long-distance runner.
Cambridge University researchers discovered that male runners are likely to have strong sex drives and high sperm counts.
But the research applies only to seasoned marathon runners. They studied 542 marathon runners, noting finishing times and the length of their fingers.
Previous studies show that men whose ring finger is longer than their index finger were exposed to more testosterone in the womb, increasing sperm count and sex drive.
The ten per cent with the most masculine digit ratios were 24 minutes faster than the 10 per cent with the least masculine ratios, suggesting increased fertility.
SUPPLEMENT THAT COULD BE WORTH A TRY
While there is little good evidence that dietary supplements improve sexual performance, one sexual medicine that experts think is worth trying is L-arginine, an amino acid the body needs to make proteins.
It’s taken as a capsule an hour or two before sex and works in a similar way to Viagra, says Dr Geoff Hackett, a consultant urologist and chairman of the British Society Of Sexual Medicine — increasing levels of nitric oxide, a chemical that dilates blood vessels.
‘It boosts chemicals needed to drive an erection,’ says Dr Hackett.
When researchers at Foch Hospital in Suresnes, France, tested the supplement on 26 men, sexual performance improved significantly — but changed little when taking an identical placebo.
The capsules are available from health foods shops at around £2.20 for 50.
