Sex and the long-distance runner

Allen and Varanasi, in Slate (May 23rd, 2016), noted that athletes at the 1988 Seoul Olympics received 8,500 condoms; 100,000 at the 2008 Beijing Games; 150,000 at the 2012 London Games; and 450,000 – including 100,000 female condoms – at the 2016 Rio Games.

In this context, and with the Olympic motto of Faster, Higher, Stronger inspiring fresh libidinous perspectives, one could speculate that swamping the 2020 Tokyo Games Village with prophylactics might boost testosterone concentrations to Olympian heights, raising the possibility of spectators staring at an empty track and wondering where the athletes are.

What is the relationship between sex and athletic performance? The American Olympic athlete Marty Liquori – ranked number one in the world for the mile in 1969 and 1971 – once observed: “Sex makes you happy. Happy people don’t run a 3:47 mile.”

Evidence-based approach

A more evidence-based approach was adopted by the authors of Sexual Activity before Sports Competition: A Systematic Review, published last year in the journal Frontiers in Physiology. They considered nine studies and found that the idea of sexual abstinence before sports competition conferring any benefit was largely based on anecdotal evidence, and that "most studies identified support the absence of negative effects of sexual activity on sports performance".

Yet a non-randomised, uncontrolled trial of one – me – found that daily training for an ultramarathon made it challenging just to raise a smile, never mind anything else, and the review above didn’t evaluate studies that investigated the relationship between prolonged aerobic exercise and libido.

So it was interesting to read the first ever scientific research-based study – published this year in Medicine & Science in Sports & Exercise – to consider Endurance Exercise training and Male Sexual Libido. Testosterone plays a major role in male sexual libido, and although the researchers – led by Prof Anthony C Hackney of the University of North Carolina – say that exercise confers reproductive benefits on sedentary males by raising their testosterone concentrations and libido; they also pointed out that the effect of endurance exercise on male libido hadn't been systematically studied.

Their year-long online survey compiled a range of data from 1,077 healthy adult males involved in endurance sports such as running, cycling and triathlons. It concluded that “men engaged in higher intensities and greater durations of endurance training on a chronic basis (ie years) are significantly associated with decreased libido scores”; speculated that the physical and mental fatigue induced by prolonged intense training may contribute to an individual’s reduced libido; and advised that “[c]linicians who treat male patients for sexual disorders and, or council couples on infertility issues should consider the degree of endurance exercise training a man is performing as a potential complicating factor”.

Prof Hackney told The Irish Times: "It's important to emphasize the benefit exercise has on an individual's health and quality of life. That said, when a man engages in high volumes of endurance exercise training, and along with that performs sessions of high intensity exercise, he can expect to experience some effect on his reproductive system. But, it is critical to realise that this phenomenon is occurring in men who've been doing chronic exercise training at high volumes and intensities for perhaps years – not in the recreational exerciser who trains less."

Prof Hackney’s team also highlighted the fact that women involved in prolonged, intensive exercise “have an elevated risk for developing menstrual dysfunctions and potential infertility”. Studies from the 1980s and 1990s suggest that an energy-deficient diet combined with exercise may contribute to menstrual dysfunction, and in terms of exercise and female fertility, it may be that high-intensity exercise prevents ovulation. For example, a 1982 report describes two Irish runners with amenorrhea who failed to ovulate in response to high doses of a fertility pill, but when they stopped running, normal or low doses of the drug restored ovulation.

What can be said about the relationship between exercise and libido in women?

Clinical psychologist Prof Cindy M Meston of the University of Texas at Austin, and co-author of Why Women Have Sex (2010) told The Irish Times: "Over the past two decades, research has demonstrated a strong link between acute exercise and physiological, ie genital sexual arousal in women, and my research has shown that activating the branch of the nervous system known as the sympathetic nervous system (SNS) can increase sexual arousal in women."

The SNS is involved, for example, in activating the so-called “fight or flight” response, and Prof Meston explained how she set up a series of studies in which women either rode an exercise bike or ran on a treadmill for 20 minutes at 70 per cent of their maximum heart rate and then viewed a sexually arousing film: “On a separate occasion,” she said, “they simply viewed the sexual film without having exercised first. We measured their sexual arousal using a device that measures blood flow into vaginal tissue, which is a physiological index of genital arousal in women that is correlated with vaginal lubrication. When the women exercised prior to viewing the films, they showed a 150 per cent increase in the amount of blood in vaginal tissue when viewing the erotic films.

Engage in something vigorous

This suggests, added Prof Meston, “that, contrary to what a lot of therapists have recommended in the past, which is that women should do something relaxing prior to engaging in sex – take a bubble bath, listen to relaxing music – my research suggests that women should do just the opposite: engage in something vigorous right before sex. Exercising prior to sex seems to ‘jump-start’ a woman’s sexual arousal.”

Prof Meston explained that acute exercise influences a number of bodily systems that could feasibly impact women’s sexual function: “Exercise has been shown to affect a variety of hormones such as cortisol, oestrogen, prolactin, oxytocin, and testosterone, all of which have been linked to sexual arousal in women. In a recent study, high levels of cortisol and chronic stress were related to low levels of genital sexual arousal in women.”

Prof Meston also discussed the role of exercise, SNS activation and female sexual function in the context of women with a history of child sexual abuse (CSA) and post-traumatic stress disorder (PTSD). “Individuals,” she explained, “with both CSA histories and PTSD diagnoses have increased levels of baseline SNS activity, and it’s been suggested that women with a history of CSA and/or PTSD who are experiencing problems with physiological sexual arousal may benefit from treatment that focuses on decreasing, rather than increasing, SNS activity during sexual activity. This might entail engaging in relaxation exercises prior to engaging in sexual activity.”

Running and sex both increase an individual’s breathing rate and, I suppose, sense of fun, but individual circumstances, will determine the amount of time we find ourself devoting to one at the expense of the other.