She is the mother of two boys, but has also had a miscarriage and an ectopic pregnancy, and has always wondered whether the physical toll of elite sport had damaged her fertility.
Laura is 32 years old and has dedicated her body to cycling for over a decade.
“In every training session I gave 100%, in every race I gave 100%.”
“I took it to the limit: if I didn’t get sick after a race, I thought, ‘Did I try hard enough?'”
This absolute commitment paid off on the velodrome. Two gold medals at the 2012 London Olympics were followed by two more at Rio 2016.
She married Jason Kenny, another cycling phenomenon, later that year and the couple had their first baby, Albie, in 2017. She then secured another gold and silver medal at the Tokyo Olympics (held in 2021).
But she miscarried in November 2021 and five months later had an ectopic pregnancy, in which the embryo implants outside the uterus, requiring emergency surgery.
“Everything was a shock – I went from being very in control of my body to being very out of control,” she told the BBC.
Laura had never worried about her own fertility before. Conceiving Albie was simple and the pregnancy went well.
But since she spoke publicly about losing her baby, other athletes have told her they had been through the same thing.
The question that remains is: can elite sport have a detrimental impact on the fertility of female athletes?
“Was my body exhausted and reacting by saying, ‘I can’t do this anymore’?” she asks.
Miscarriage is common. About one in four pregnancies ends before 24 weeks and many occur at a very early stage. Most couples never find out why.
But are elite athletes at greater risk of some type of fertility problem?
Emma O’Donnell, a physiologist at Loughborough University, says the lifestyle of a professional athlete puts a different strain on her body.
Elite training burns an extraordinary amount of calories, and as a result, athletes’ bodies are often lean and muscular, containing very little body fat.
If they don’t eat enough to keep up with their calorie burn, problems with their menstrual cycles, such as interruptions for months or even years, are “very common,” says O’Donnell.
Almost two-thirds of female athletes experience interrupted periods, particularly in endurance sports. High percentages are also recorded among elite gymnastics, ballet and figure skating practitioners. Among the general population of women, the percentage of interrupted periods is 2% to 5%.
The absence of menstruation can be a sign that ovulation (or egg release) is not happening.
How does this happen in the body?
“We’re not 100% sure,” says O’Donnell, but the main idea is that conceiving a baby is a task that takes so much energy from the body that the brain stops the entire reproduction process if it thinks the body doesn’t have enough energy. .
This starts in the hypothalamus, a small structure in the center of the brain that detects the body’s nutritional status.
Just below the hypothalamus is the body’s hormone factory – the pituitary gland.
Normally, the gland releases hormones that travel to the uterus and ovaries to control the monthly menstrual cycle and egg release, which makes pregnancy possible.
But if the hypothalamus is not happy, this process is interrupted and ovulation does not happen.
“If you’re not ovulating, you can’t have a baby. You can’t conceive because there are no eggs being released,” says O’Donnell.
The main factor for this appears to be the large number of calories burned during physical training, which can make athletes have difficulty eating enough food to compensate.
This phenomenon is known as relative energy deficiency in sport (RED-S) and was first recognized by the International Olympic Committee in 2014.
But other factors are also likely to be involved, says Professor Geeta Nargund, a consultant at St George’s Hospital and medical director of Create Fertility.
Fat in the body helps produce the sex hormone estrogen.
“If sport is affecting body fat level, then clearly there is an effect on estrogen levels,” she says.
Psychological stress — potentially caused by the pressures of training and competition — can also disrupt the menstrual cycle.
“We see this in women with high levels of anxiety,” O’Donnell said.
The cessation of menstruation and the release of eggs is the most clearly recognized impact on a female athlete’s fertility, but this should resolve itself when she retires from sport, she notes.
Ectopic pregnancy and miscarriage
For athletes who manage to get pregnant, there are still risks. After an egg is fertilized, it must implant in the lining of the uterus. However, in an ectopic pregnancy, the egg implants elsewhere, usually in the fallopian tubes that connect the ovaries to the uterus.
Around 11,000 pregnancies a year in the UK are ectopic. It’s not entirely clear why they happen, although inflammation and scar tissue in the fallopian tubes may increase the risk.
“But in this case, I don’t see a direct link between sports and an increase in the incidence of ectopic pregnancy,” says Nargund, who has treated athletes with fertility difficulties.
However, she said there may be a link between very intense exercise in the first three months of pregnancy and miscarriage – although much more research is needed to know for sure.
She cites a large Danish study that followed more than 90,000 women and suggests that the more intense exercise women did, the greater their risk. This happens especially with weight and high-impact exercises.
“If you’re at Laura Kenny’s level of elite athletes, you’re at the top,” says Nargund.
But she explained that the study’s findings need to be interpreted “with caution” because the way the study was designed indicates there may be other explanations that were not considered.
Meanwhile, a very small study of 34 Norwegian athletes found no increased risk of fertility problems, including miscarriage.
“We need to do a lot more research when it comes to sports, exercise, hormonal balance and reproduction,” says Nargund.
Athletes freezing eggs
Lauren Nicholls played elite netball for ten years and then had two children, before becoming coach of the Loughborough Lightning, a British team. She says the conversations current players have about fertility are different from those she had with her former counterparts.
“I know some players who are a little older and they froze eggs and put off those decisions about having a family,” she says. “Because now they’re worried about their career.”
Reconciling the dream of being an elite athlete with starting a family has always been a complicated challenge. For women, peak fertility years coincide with their physical peak.
Male athletes are also not immune to fertility problems.
Burning more energy than you consume can affect testosterone levels, cause sperm abnormalities, and even erectile dysfunction.
But for Emma Pullen, a sports exercise researcher at Loughborough, the lack of definitive answers about the impact of elite sport is emblematic of how poorly female athletes have been researched – from fertility to injury risk.
She said that research on women is falling behind the attention given by science to men’s sport.
“We’re seeing the repercussions of this with the increasing professionalization of women’s sports and more female athletes than ever before,” says Pullen.
Overall, Nargund argues that female athletes likely face more fertility challenges than other women.
“There appears to be a fertility problem due to the potential effect [do esporte de elite] ovulation, including a potentially greater risk of miscarriage,” she says.
But a definitive answer about exactly how much elite exercise is too much is unclear. And that’s enough for Dame Laura, for now.
“I think the conversation itself is really important because I want people to start talking,” says Laura. “Honestly, I would love it if it was a lot more open.”
However, the relationship between exercise and fertility affects us all, even if we are a long way from Olympic glory.
How does exercise affect overall fertility?
Most men and women benefit from exercising and losing excess weight before trying to get pregnant – this is known to increase fertility.
Regular physical activity reduces stress, improves sleep and makes menstruation more regular in people with the hormonal condition polycystic ovary syndrome (PCOS).
But amateur athletes who train intensely can also end up depleting their energy, stopping their periods or making them irregular.
“Not exactly to the same extent, but it happens,” says O’Donnell.
Ensuring there is a balance between energy intake and production is “very important for ovulatory cycles” and key to maintaining reproductive function, she adds.
“[Atletas amadores] are not aware of the fact of how many calories they actually need to eat to meet this energy demand.”
This text was originally published here.
