Training with your menstrual cycle
A very comprehensive, science backed guide to what we know, what we do not know (yet) and a lot of practical advice for women who exercise regularly.
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Training with your menstrual cycle seems to pop everywhere in the last few years and I’m so totally here for it! That said, I am finding it really hard to get behind sweeping statements, hype, buzz words and jumping on a bandwagon without actually understanding the science and practical considerations, as that leads to misinformation and confusion - I am very much not into that!
I have noticed far too many cases where generalized info is provided without appropriate context (mostly on social media, obviously), but one that stuck with me recently was in an online chat thread about health trackers. A woman was wondering if she should be tracking her sleep and symptoms/observations throughout her menstrual cycle because she is using a hormonal IUD and does not get a regular bleed as a result. She also shared that her coach is adjusting her training based on her menstrual cycle, but she did not know what was actually being adjusted and has never shared symptoms with her coach to adjust things based on. Hmmm… A few red flags here!🚩 Two main issues come to mind:
How can an effective solution be provided when you do not know what issues the individual is experiencing?! Kudos to the coach for being willing to make adjustments, but both coach and athlete are completely missing the point here: it’s just ticking a box to say it’s done without actually understanding the why and doing things properly, which doesn’t help the athlete at all in the end
Many women do not know their body well enough and that, in my opinion, is a big problem
A recent conversation with a friend whose tween daughter (a competitive swimmer) recently got her first period, revealed that a lot of girls on the squad skip training sessions during the week of their period. What?! 🤯. How is that still a thing in 2023?!
This week’s post is all about training with the menstrual cycle - What we know, what we do not know (yet) and practical advice for women who exercise regularly. My goal is to be a bit different than other resources out there and instead of telling you to do x, y, z, my goal is to empower you to take control of your experience as a female athlete by giving you ‘food for thought’ and some tools to make your own decisions with regards to your body, sharing science backed resources, social media accounts by sport scientists that offer solid, accurate, relatable content and more.
I think it goes without saying (but I’ll say it anyways) that this is not just for women - Men, this is for you also… Especially if you are a coach working with women, an athlete training with women, a partner, brother, father to young women, etc.
Alright, grab a cup of your preferred beverage (coffee, in my case) and lets dive right in!
I want to start by saying that we need more research on women. A LOT of research is based on male data and guidelines often extrapolate data from men and apply it to women, which is far from ideal. We need change, without a shadow of a doubt. The shift is happening slowly, but there is so much work to be done in that area… I stepped away from the world of academia in 2010 after grad school, but to be honest this topic seriously makes me consider going back to university to do some research on female physiology and biomechanics.
Menstrual Cycle basics
Understanding how the menstrual cycle works can help you develop a better understanding of how your own cycle works. You can use that information to help you get pregnant, avoid getting pregnant, manage menstrual symptoms and be able to tell when problems arise.
I am assuming most of you know the basics, but here is a super quick overview. The length is a cycle is 21-35 days (21-28 is the average) and there are a few phases within each cycle (the exact number of days varies between individuals and can change over time, too):
Days 1-5: Bleed. The range is 1-7 days, 5 days on average
Days 6-14: The lining of the uterus prepares itself for possible pregnancy by becoming thicker and richer in blood vessels
Days 14-25: Around day 14, an egg is released from one of the ovaries and heads to the uterus. If sperm is present in the fallopian tube, fertilization can happen and the fertilized egg will travel to the uterus to implant in the uterine wall
Days 25-28: If the egg was not fertilized or implantation does not happen, hormonal changes signal the uterus to prepare to shed its lining
The cycle gets repeated
Days 1-14 are considered the Follicular phase / low hormone phase, with low luteinizing hormone (LH), follicle stimulating hormone (FSH), progesterone and slowly increasing levels of estrogens through this phase. Ovulation is around day 14, where there is an increase in estrogen and luteinizing hormone, followed by the Luteal phase / high hormone phase where both estrogen and progesterone levels are high.
Your menstrual Cycle is gold
It gives you very important insight into your health as a women and as an athlete. A natural cycle with phases as outlines above is associated with good bone health and better fertility outcomes (if applicable). Low energy availability that leads to irregularity or the loss of your period is a big red flag as it can affect bone health, lower metabolic rate, reduce immunity, protein synthesis and have a negative impact on cardiovascular health.
Recreational athletes are just as susceptible to RED-S, overtraining, etc. It is hard to meet energy needs for training and staying healthy and your menstrual cycle is your body’s way of telling you if everything is okay or alerting you if things are heading in the wrong direction for your health.
Performance and the Cycle Phases
There is higher pain tolerance and many women report higher energy levels and better mood during the Follicular phase, so perhaps high intensity workouts are best here. At the later stage of this phase and around ovulation, where estrogen levels are at their highest, strength is at its peak. Load can increase, there is more resilience to stress and immune response is higher.
During the Luteal phase, progesterone levels increase, along side estrogen, making us feel a bit more tired, energy is lower and muscle recovery might be lower compared with the follicular phase. Weight might increase due to fluid retention, breathing rate and body temp increase potentially affecting exercise in the heat and sweating response could be delayed, affecting thermoregulation.
The information mentioned above is in theory and research has been limited and inconclusive. Sadly, this is where things seem to get confusing and misleading. I have seen some resources claiming that the information above means that women should do more intense training sessions during the follicular phase, then do easier sessions during the luteal phase. Some sources go as far as saying that gentle exercise like yoga and no intensity is the way to go during the later stages of the luteal phase and during the bleed phase (which is of course the early follicular phase).
F’ that. I call total BS on that kind of blanket interpretation and application. Afterall, we know that women are capable of winning medals at ALL phases of the menstrual cycle! You are not a fragile flower that wilts at that time of the month and you can certainly do as you wish, intensity and all, if you feel good and feel like it.
In fact, estrogen and progesterone are at their lowest when women are on their period, so in theory, it can be a great time of month to push harder, set PRs, and see an increase in performance. Of course, this depends on YOU, the individual.
Injury Risk
During the late follicular phase and around ovulation, strength is at its peak, but that could come with some potential risks as there might be evidence showing that muscle and tendon injuries are more common in the late follicular phase compared to the early follicular or luteal phase. The evidence is mixed and more research and observation is needed.
Hydration and the Cycle
The increased levels of progesterone in the luteal phase could increase sodium losses in theory, which is potentially a problem for performance because of the direct relationship between blood sodium and blood plasma volume. Low total body sodium leads to a reduction in blood plasma volume which then leads to increased heart rate during exercise as a compensation pattern. This also affects thermoregulation (see below).
In practice, this is a lot less clear though. At the end of the day, the overall effect of the menstrual cycle on sodium and fluid balance seems to be fairly minimal and does not have major consequences, especially in the early follicular phase, and the body is pretty smart in having mechanisms in place to prevent major deviations that could cause problems.
Core Temperature & Heat Tolerance
Body temperature is increased and sweating response could be delayed, potentially affecting thermoregulation during the luteal phase due to the high levels of progesterone, which could have an effect on the body’s ability to tolerate exercise in hot and humid environments. This means you might want to focus more on cooling strategies and proper pacing to help cope with the heat better.
This is all in theory. In practice, research has shown that menstrual phase did not affect performance in the heat… It is best to track you own response to heat at different phases of your cycle and take action based on your own needs and observations.
Macronutrient & Micronutrient
There is some evidence that shows the considerations below, but take these with a grain of salt as findings are conflicting and studies show either very minor differences or no differences at all across the menstrual cycle, meaning a lot more evidence is needed before we can give solid, meaningful recommendations here.
Calories - Resting metabolic rate is higher during the luteal phase, and you might feel more hungry, so caloric intake might need to increase as a result.
Follicular Phase - During the follicular phase, muscle carbohydrate stores are lower and there is reduced ability to use these stores, and more carbohydrates are used for energy, so in theory, eating more carbohydrates before intense training sessions during that phase could be beneficial. Of course, one might argue that this is common sense before high intensity sessions as it is.
Luteal Phase - Women might rely less on carbohydrates compared with the follicular phase, burning more fat as fuel. You might have higher protein needs to support recovery and need good quality fats (especially omega 3’s), both of which can also help with keeping you full if you feel like hunger is increased during this phase.
It seems that when you consume adequate carbohydrate amounts to support your activity level, there isn’t a significant difference in glycogen storage between menstrual cycle phases.
During your period - Remember the Iron and hepcidin article published mid February? Well, here is a bit extra and relevant information I did not mention there - When bleeding starts, hepcidin release after training decreases and iron absorption increases. You might want to include iron rich meals and increase magnesium and zinc intake.
Immunity & Inflammation
Inflammation levels are higher after ovulation and menstruation is obviously inflammatory. Some women also report getting sick more often right before their period. It might make sense to pay extra attention to immunity and recovery and focusing a bit more on adequate sleep, hydration and quality nutrition (more colorful fruit and vegetable, perhaps?).
Sleep Variations
Estrogen levels start increasing right before ovulation. This can affect melatonin and sleep. The follicular phase may be associated with decreased sleep efficiency and increased Deep/slow wave sleep compared with the luteal phase.
After ovulation, sleep is disrupted and body temperature is increased, which could negatively affect sleep patterns. Reduced sleep quality right before and during menstruation is common in women with PMS or painful menstrual cramps.
It is best to track your sleep throughout your cycle to see how your sleep is affected. I hope you are starting to see a theme here?!
The Effects of Birth Control
Most women use some form of birth control, which obviously affects the menstrual cycle. This is a massive topic on its own so I will keep this short.
IUD’s - Inserted into the uterus by a doctor, there are two main kinds: 1) hormonal and 2) non hormonal (copper). Most women will still have a natural cycle on the hormonal IUD, meaning ovulation will still happen, but they might not have a bleed (this depends on the type of IUD as hormone levels vary and individual variability). With the copper IUD, you will have a natural cycle (side note: if you have heavier periods, it might not be the best choice for you)
The birth control pill suppresses the natural production of estrogen and progestin to prevent ovulation all together. The bleed is not a period, it is a withdrawal bleed and doesn’t indicate a healthy cycle, so it might be harder to detect any health problems since there is no natural cycle on the pill. The research around effects of the pill on performance is not consistent.
It is really important to note that women who are taking the pill are always in a ‘low hormone phase’ and attempting to train with their cycle is completely pointless. That does not mean they should not be tracking symptoms though, as there could still be variations throughout the ‘cycle’ and it is potentially a good habit to develop anyways.
What we don’t know yet
To be honest, there is still a fair bit we don’t know and the fact that women vary in their cycle does not make things easier for science, not to mention the birth control curveball... Some of the info above is in theory only and in practice, things are a heck of a lot less clear and the evidence is far, far from conclusive - As mentioned above, findings are conflicting and studies show either very minor differences or no differences at all across the menstrual cycle.
Since there isn’t enough research at the moment, and the evidence we do have shows very small differences, recommendations on adjusting your training based on the menstrual cycle are not reliable overall and we really should not make sweeping and generalized recommendations at this time.
In addition, most of the research has focused on looking into the pre defined cycle phases, but there are day to day hormonal changes that happen and the phase transition periods are important but are less researched.
Lets get practical
Okay, so maybe we don’t need to drastically change our training based on our cycle… But I think we can all agree that there are differences between the phases and perhaps we can tweak things a little bit here and there for our (training) advantage. Here are some points for your consideration:
Training zones should be set as a range not a target (which is not exactly news, anyways). Based on symptoms, adjust within the range based on how you are feeling. For example, during the follicular phase you might train at the higher end of the range and during the luteal phase, you might train at the lower end of the range. It’s all good - You are still going to get training benefits and adaptations within those ranges!
Every cycle is individual to each woman and can vary month to month also. You need to track your cycle over extended periods of time to get a better understanding of your individual trends. Why play a guessing game when you can make informed and empowered decisions based on your personal needs?!
Don’t be too strict with periodization - You can shift your recovery week, or recovery days a bit to fit within your individual needs and cycle related symptoms… It’s okay not to follow a typical, pre-set pattern. If you know that you always feel flat on day 25, but not on day 23, its okay to shift key sessions a bit - But it does mean you need to track things appropriately and if you are working with a coach, you need to communicate with him or her effectively. Afterall, its easy enough to finesse your training week to make sure everything fits your individual needs.
You need to know what makes you feel better. If you get cramps before and during your period, what are the strategies that help you with that? If your lower back and hips feel tight around ovulation, what alleviates the discomfort? If hunger levels vary, what should you do about that? The first step is to be aware of these things by tracking your cycle and symptoms. The second step involves a bit of trial and error to see what works for you, ideally consulting and communicating with your coach and/or a professional like a sport scientist, to make sure you are not just ‘throwing darts in the dark’
For racing… You can’t really control what time of the cycle your race will fall on, so it is a matter of estimating where in the cycle you will be and then just be ready to deploy appropriate strategies to suit your individual symptoms. Of course, you need to track your symptoms for a period of time for this to work, and take into account that taper and event related stress could affect your cycle too.
What should you track?
Since cycles are unique, vary women to women, can vary month to month and change over the years, it is important to keep track of your menstrual cycle. Now that we established that you should track your cycle, what exactly should you be tracking? Here are some common things to track through the entire cycle:
Overall mood and motivation to train
RPE (Rate of Perceived Exertion) during training sessions during each phase of the menstrual cycle: The goal here is not necessarily to track every single training session, but to see if RPE is higher right before your period, what happens once period starts, what happens during ovulation, etc.
Anything that tends to affect you before and during your period, like cramps, bloating, GI issues, headaches, lower back discomfort, etc. The same goes for ovulation.
Cravings and hunger levels throughout each phase
Sleep quality and duration
Response to heat and humidity throughout the cycle, especially if you plan on racing in the heat and you need to acclimate to it
Spotting and bleed patterns
Apps & Tracking Tools
There are a ton of different apps out there, and I’m not going to tell you which one you should use as like anything else, the best app is the one that you actually use regularly. My suggestion is to try a few different apps, pick one that you find easy and simple to use, then actually use it consistently… Here are some recommendations:
Wild.AI (designed for athletes)
FitrWoman (designed for athletes)
Apple health app
Wearables like the Oura Ring and Whoop
Smart watches: FitBit, Garmin, Samsung, apple watch
Training Peaks
If you are working with a coach, you should share some of the information with them and some apps aim to make it easier, For example, the FitrWoman app has a coach subscription for coaches whose athletes are using their apps. As a coach, I personally prefer my athletes log their mood, sleep data, menstruation and a few other metrics like HRV (if available) directly in Training Peaks as it’s easier for me to manage everything in one place.
What do I use?! In case you are curious… I am personally using my Oura ring to track everything as it allows me to easily correlate my cycle with sleep data and body temperature, but I also use Wild.AI because the app pulls all my data from Training Peaks, Strava and Oura ring. I use it to add other symptoms and can see my trends visually, in one ‘hub’. I like how I can easily see where I am within my cycle, but I am not necessarily a fan of the generic nutrition and training recommendations provided in app.
Reliable Social Media Accounts
If you are going to get advice and information on social media, lets make sure you get it from reliable and credible sources, shall we? All the Instagram accounts below are by researchers directly working in this area and/or sport scientists who separate trend from fact, which I appreciate. All of them have links to their work in their bios, which I think is worth exploring.
Kelly McNulty - periodoftheperiod
Sam Moore - sammoorestrong
Umi Health - umihealth
Alyssa Olenick - doclyssfitness
Abbie Smith-Ryan - asmithryan
Female Athlete Podcast - femaleathletepod
Scientific Reading / References
To no ones surprise, I went a bit overboard with the reading list and it is quite long, so I decided to include all the scientific papers I read while writing this article in a pdf. You can view it HERE.
Phew, that was a lot of information… Sorry, not sorry about that! I hope you found this article valuable and interesting. I would love to hear your thoughts, so feel free to comment below and share this post with others.
Please keep in mind that I plan on doing a similar post for those in peri-menopause and menopause at some point later this spring / early summer.
Next week’s theme is Dynamic Cycling Analysis (aka bike fitting). I will explore fit considerations for road vs gravel bikes - Should you set them up the same? If they should fit differently, why? Quite a few things to discuss… Stay tuned!
I think this could be really interesting for my trail running listeners/readers as well! If you're interested in coming on the show to chat about it, let me know. It would be great to have another Vancouverite on and it would also be great to spread the word a bit!