Did you know that the way we exercise (or not) can have an impact on our fertility? In this article we look at the science behind why this matters and how you can use it to help with your conception:

So I think it’s fair to say that most of us realise that exercise is a good thing. However, our modern lifestyles sometimes don’t make it very easy, and believe it or not, there are some pitfalls around apparently ‘healthy exercise’ that can actually hurt our fertility and hormonal balance…yep…

Take me for example. I have always thought of myself as a very health-conscious person who enjoys (once I get there!) exercise. However, what I didn’t realise is that my ‘healthy’ lifestyle and exercise regime was actually hurting my fertility.

How?

Well, with hindsight it seems crazy that I didn’t see it coming, but I honestly believed I was being healthy, particularly with exercise. Here’s how it happened:

My previous job in investment banking = long periods of time behind a desk, and I mean loooong periods, where my main activity was walking to the cafe (about 20 paces from my desk.) I would finish work and then go straight to intense work outs in short, sharp bursts (HIIT, spin or pounding a treadmill) at least three to four times a week. So long periods of being very sedentary against sharp bouts of very intense frequent exercise. Great if you want to stay slim and get good cardio, but not so good if you want a healthy hormonal balance, which is key for conception.

So, when I realised there was a potential link between my exercise habits and my fertility, I delved into the latest hard medical and scientific research around the subject. Here are a few of the key points I found when it comes to fertility and exercise.

The good:

ONE: Exercise really does have an impact on fertility and its not just simply controlling weight (which is an important factor around fertility and growing a healthy baby). Regular physical activity has been shown to be effective in regulating our blood glucose control and our sensitivity to insulin i.e. it’s hormone balancing regardless of your BMI. Why does this matter? Well, if you have PCOS it matters a lot (click here for a reminder as to why) but for everyone else ‘insulin sensitizers seem to have a beneficial effect on ovulatory function and fertility’, PCOS or not. (1)

TWO: I’m sure I’m not the only one that heads into a work out dreading it but comes out buzzing and feeling a lot better. That’s the endorphins for you. We know that stress and mood is very important for fertility. We also know that being very stressed is one of the major enemies of conception (click here for a reminder of the science behind stress). Regular exercise has been strongly associated with reduced stress, anxiety and depression. Tick.

THREE: boys – this applies to you too. I am constantly surprised when people assume that fertility is only a women’s issue. However, we know that sperm counts are rapidly on the decline (click here for more on what is behind that). We also know that exercise has an impact on sperm, with research showing that: ‘moderately physically active men had significantly better sperm morphology.’ (1)

HOWEVER – and this is where I was going wrong…here’s the not so good:

FOUR: too much is as bad as too little. Performance athletes and people who participate in more extreme exercise regimes have been known to suffer from fertility issues – once again stemming largely from the impact it has on hormones; after all extreme exercise is a stressor. I hadn’t realised but my own regime and the general trend towards high intensity exercise was actually impacting me: ‘Increased frequency, intensity and duration of exercise were found to be significantly correlated with decreased fertility in women.’ (1)

FIVE: the same applies to guys, and in fact studies have shown that ‘bicycling more than five hours per week has been demonstrated to have a negative correlation with both total motile sperm counts and sperm concentration.’ Eeek! Once again it comes down to intensity as well: ‘In males where results seem more controversial, it has been observed that prolonged intensive exercise (and training) may lead to adverse effects on physiological systems, particularly the reproductive system and fertility with alterations in reproductive hormone levels…abnormal sperm morphology and reduced sperm motility.’ (2)

SO: like most things in life it, think Goldilocks: not too much and not too little.

SIX: what about exercise around embryo implantation? Sounds a bit OTT? Well actually your body reacts differently to exercise depending on where you are in your cycle (yep, I didn’t know that either – click here to learn more). The time between fertilisation and implantation is of course a vulnerable one, so I wondered whether or not exercise could have a negative impact. Once again, it’s just about avoiding the extremes. The science suggests that moderate activity and increasing insulin sensitivity ‘may be beneficial to implantation’ as it reduces the chances of what is known as ‘hyper-insulinemia’, which reduces key molecules that appear to help adhesion during implantation. (4) The flip-side is that ‘vigorous activity lowers leptin levels. Leptin appears to be important in regulating embryo implantation and endometrial receptivity.’ (4) So it seems there’s no reason to avoid moderate work outs at this time.

Conclusion: the first point to know is that regular moderate exercise is undoubtedly beneficial for fertility in men and women. However, very regular extreme high Impact/intensity work outs could potentially have the reverse effect, as of course exercise (particularly to that extent) is a stressor on the body. Everyone is different so it is important to listen to your body and if in doubt consult an expert.

So, what type of exercise should you do?

If you’re not doing things to extreme, most exercise is good. Resistance training, cardio and of course yoga, Pilates and swimming all have their benefits. The other thing is to find exercise that you enjoy. As long as you are not going to extremes it should have a positive effect. However, click here for some wise words from pre- and post-natal specialist Natalie Ferris.

References:

1. SHARMA R, BIEDENHAM KR, AGARWAL A: Lifestyle factors and reproductive health: taking control of your fertility: Reproductive Biology and Endocrinology: RB&E: 2013: 11: 66

2. SKAKKEBAEK N, RAJPERT-DE MEYTS E, JUUL A: Male Reproductive Disorders and Fertility Trends: Influences of Environment and Genetic Susceptibility: Physiological Reviews: 2016 Jan 96(1): 55-97

3. GASKINS A, WILLIAMS PL, CHAVARRO JE: Maternal physical and sedentary activities in relation to reproductive outcomes following IVF: Reproductive biomedicine online: 2016 Oct: 33(4): 513-521

4. EVENSON KR, CALHOUN KC, STEINER AZ: Association of physical activity in the past year and immediately after in vitro fertilisation on pregnancy. Fertility and Sterility. 2014 Apr: 101(4): 1047-1054

5. HINMAN SK, SMITH KB, SETH SMITH M: Exercise in Pregnancy: Sports Health. 2015 Nov: 7(6): 527-531

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