Sportmed-Corner

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with Kelly McNulty

Author: Patrizia Zanetti Picture: Kelly McNulty Kelly McNulty (25) is a PhD student at Northumbria University in Newcastle upon Tyne, England. McNulty’s research interests are focused on women and girl’s health, the menstural cycle, hormonal contraceptives, breast health, pelvic health, pregnancy and menopause, applied to sport and exercise. She founded and hosted the podcast “The period of the period“, which is a digital education platform.

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SPORTFISI@: At the moment everyone is talking about how women should train with regard to their menstrual cycle (in a cycle-oriented manner). How important do you think it is that this taboo topic is addressed in the sporting world?

McNulty: For a long-time sport and performance support, in sport, has largely been designed for men. For instance, the support we apply to performance whether that be training or nutrition or whatever else is largely based on what has been researched in men, or what has been successful for male athletes. For a long time, that’s how it worked without anyone really questioning whether this direct transfer was valid. However, if we think about it logically this might not always be the most optimal approach as it would almost be naïve to assume that all research in male athletes can be directly applied to the female athlete – given what we know more about the anatomical, physiological and endocrinological differences between the sexes today. It seems evident that female athletes will benefit from sex-specific research and guidelines that look at their physiology – such as the menstrual cycle and how this might be impacting on the likes of performance and training. I guess it seems almost more important now as across the entire board we’ve had an increase in the number of women participating in sport and exercise. For example, the percentage of women competing at the Olympic Games has increased from 26% in Seoul in 1988 to an all-time high of 49% in Tokyo this year. Just like men, women want to get faster, stronger, achieve PBs – whether that’s at your local 5 k every weekend or at that top level gold medal winning performances – we – as coaches, practitioners, athletes, and researchers have to know more about a women’s physiology and how this might impact on the likes of performance and training. I guess that was a long way of saying I think it’s so important that these female specific factors are considered in the same light as other physiological functions that we normally consider in sport and exercise.

How does the menstrual cycle affect women physically and mentally?

The menstrual cycle itself refers to this cycle of hormonal fluctuations that occurs roughly every month in women of reproductive age, so from around the age of 12/13 until 50. Whilst the main aim of the menstrual cycle is to support reproduction, because we have hormone receptors for oestrogen and progesterone all over our bodies (not just in our reproductive system, they’re in our muscles, in our brains, in our gut), the fluctuations in these hormones across the menstrual cycle influence many other of our physiological systems – such as our cardiovascular system, our respiratory system, our metabolic system, and our muscular system. So, basically, these hormones can have an effect around our entire bodies and because of this they can subsequently affect things like performance, training, and recovery. These hormones can have many different effects on our bodies which can then affect us physically and mentally. There’s way too many to mention now, but for example, oestrogen is known for its anabolic and muscle-building effects, its excitatory effects on neuromuscular signalling and is thought to have a protective function against muscle damage by reducing the likes of muscle soreness and swelling. Additionally, it is a feel-good hormone which can influence your motivation to perform and train in a positive way. Given this information it could be theorised that now might be a good time to switch your focus to strength training and some evidence suggests that follicular phase-based resistance training (strength training more in your follicular phase than any other phase of your cycle) is better than regular or luteal phase-based training for developing strength and muscle mass. In contrast, progesterone is thought to inhibit the effects of oestrogen, as well as having its own physiological effects. For example, progesterone is known to influence your body temperature - which rises by approximately 0.3 degrees Celsius in the second half of our menstrual cycle (the luteal phase) and although this temperature rise does not sound like much, it could mean that some women might feel hotter during training which can make them stop, slow down or perceive exercise to be harder in this point in their cycle, which could be further exaggerated in hot or humid climates. Therefore, some women might find that the use of cooling strategies is an effective tool to overcome any potential negative effects, more so in this second half of the cycle. I could go on and on but ultimately, the key takeaway here is that the menstrual cycle can affect women physically and mentally and that these effects are different between individuals and in the same woman across her lifespan, therefore the menstrual cycle is an important factor that we need to be able to discuss and consider when it comes to your sports performance and training.

What influence do these hormone fluctuations have on planning training? Is there a disadvantage compared to male partners (athletes, competitors)? If so, why?

Personally, I don’t think they are a disadvantage at all, and I think we need to change that perception of women’s hormones being a negative thing – we are all hormonal all of the time and it’s a good thing! And ultimately in sport we rarely compete male vs. female and therefore I don’t think we need to think of it as a ‘battle of the sexes. Instead, I think we should see our hormones and physiology as a woman as an advantage – so as I talked about before there is evidence suggesting that follicular phase-based resistance training (strength training more in your follicular phase than any other phase of your cycle) is better than regular or luteal phase-based training for developing strength and muscle mass. It’s interesting to think that we could potentially make the most of our physiology at this point in our cycle to gain these types of advantages. Ultimately female athletes have won competitions and set world records at all phases of their menstrual cycle. So, hopefully you can see that these effects are not necessarily

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negative or a disadvantage and might help you to gain a better understanding of where you are in your cycle, what’s happening with your hormones, and how to adjust your performance and training accordingly so that you can get the most out of yourself on any day of your cycle.

Red-S Syndrome: Osteoporosis caused by a long duration without periods, how dangerous is it really?

Yes, so RED-S is a condition of low energy availability affecting male and female athletes of all levels and ages, but female athletes have a warning sign of irregular cycles or absent periods, known as amenorrhea. RED-S has a wide range of adverse effects on all physiological systems and can seriously compromise long term health and performance, for example like you mentioned, bone health. However, often with the elite female athlete space RED-S is considered normal. However, it’s vital to stress that not having a period is not a normal part of training and performing and it should be something you speak to your doctor or support practitioner about as soon as possible.

How far do you advise your patients to go in cycle-oriented training? For example, do you suggest strength training mainly in the first phase of the menstrual cycle and stabilisation training mainly in the second phase?

As a start, I recommend everyone to have a go at tracking their cycle to learn more about their own unique menstrual cycle. For example, what symptoms they experience and how they perform, train, and recover on certain days. However when it comes to cycle-oriented training I think we can all be placed on a spectrum from say those who breeze through their menstrual cycle and probably experience very little training and performance effects to those at the other end who definitely do not breeze through their cycle, so they might have lots of symptoms and be very sensitive to hormonal fluctuations and experience a lot of different training and performance effects – your athlete can be sat at anywhere along this scale. In my opinion, if your athlete has tracked their cycle and found no real differences then cycle-oriented training is probably going to have little effect for them. In contrast, if your athlete has tracked their cycle and noticed lots of performance and training changes – then they are likely to benefit the most out of cycle-oriented training. Overall, whilst scheduling performance and training based on the menstrual cycle is an interesting concept, and to some degree very popular at the moment in the press, currently because of the lack of research we don’t have enough published, high-quality evidence to suggest general guidelines for cycle-oriented training. So, instead, the focus should be on the individual so that we encourage female athletes to start tracking their own individual cycle and collect their own data and use this to inform training and performance if needed, whilst using the evidence-base that is available to them currently to direct these decisions. Why does cycle-oriented training also include non-hormonal contraception? Additional question: is it better to use different contraceptives (mini pill, IUD)?

Cycle-oriented training is based on the evidence that fluctuations in our sex hormones – oestrogen and progesterone – across the menstrual cycle can influence many of our physiology systems which can lead to changes in performance, training, and recovery, for example. So, if you’re a naturally menstruating women this might affect you. Now, because non-hormonal contraception use does not alter our hormonal profile it means non-hormonal contraceptive users, such as those who use the copper coil, or the IUD still experience this fluctuation in sex hormones and therefore are still open to any potential performance and training effects. However, on the flip side we need to remember that not all sportswomen experience a natural menstrual cycle, and many female athletes use hormonal contraceptives or have internal changes in their cycle, such as irregular cycles or amenorrhea so we need to be able to understand how these different hormonal profiles can influence performance and training to be able to cater for them also.

What advantages do women gain from cycle-oriented training?

Again, the advantages are going to depend highly on the individual but at the elite level where we are always searching for small improvements – so marginal gains – understanding the effects of female sex hormones on our physiology and how this links with performance and training might lead to these small gains needed for success. And the same is also true at a recreational level in terms of performance and training improvements, but also at this level having an understanding of the menstrual cycle and its potential effects will also help us be able to keep women and girls active across their entire lifespan. Finally, I think the biggest advantage we get comes from the application of doing the basics right in training plans, but also from creating an environment where athletes can openly discuss their menstrual health and where education on these topics is a part of this, as ultimately cycle-oriented training is going to be futile if basic training principles are not in place and if you have an environment that doesn’t allow these factors to be considered or discussed.

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