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  • Writer's picturethe_uphill_runner

Go With The Flow

I ran my two most recent races during my period. The first was the virtual Vitality London 10k, on day 4 of my cycle, where I achieved a massive postpartum PB and felt really strong throughout. The second was the Goodwood Running GP half marathon, where I’d just got my period that morning, so I felt sluggish and perhaps didn’t run as well as I could have had the race taken place a few days before or after. To help me understand more about how my menstrual cycle can impact my running performance, I invited Emily Plummer, founder of WISE women and frequent buggy runner, to provide some explanations and advice.

1. Which different hormones/phases should women be aware of regarding exercise and their menstrual cycle?

In simple terms the cycle can be split into three sections:

  • Follicular (or Low Hormone) phase (from day 1 of your period to ovulation)

  • Ovulation

  • Luteal (or High Hormone) phase (from ovulation up to the start of your next period)

Let’s think about what your body is doing over those phases. If you take an average 28 day cycle, most women will ovulate in the middle of their cycle, around day 14. The egg is released and the body essentially prepares itself to get pregnant. The release of the egg stimulates an increase in the reproductive hormones progesterone and oestrogen. Progesterone encourages the thickening of the lining of the uterus so it is ready to receive a fertilised egg. It takes a lot of our nutrients and energy to build this lining, so we can feel more fatigued during this time.

When our body establishes that there is no fertilised egg it sheds the lining and you get your period. The hormones oestrogen and progesterone both drop right down and your body goes into a more relaxed state. An increase in oestrogen at around 10-13 days stimulates the little known luteinizing hormone which encourages the egg to be released. Then you ovulate again…

With that all in mind let’s look at how these hormones can affect us in relation to exercise.

Increased progesterone in the second half of our cycle leads to:

  • Increased core temperature - we often feel warmer when exercising in this phase and become less tolerant to heat

  • Changes in how we sweat. Sweat is delayed so we hold onto the heat for longer - also making us feel hotter

  • Sweat is also more concentrated - you may loose more salts during this phase

  • Increased Progesterone leads to increased muscle break down - you may feel more sore after a run than normal

We see increased oestrogen late in the Follicular phase and across the Luteal phase. Increased oestrogen:

  • Interferes with our serotonin levels leading to a feeling of fogginess or loss of ‘mojo’

  • Increases fluid retention, giving you that uncomfortable bloated feeling

But on a positive note increased oestrogen stimulates muscle development and increased bone density. So it’s not all bad!

Finally, both increased progesterone and oestrogen interfere with our storage of glycogen. To put it simply, when progesterone and oestrogen are elevated, carb loading before a run will not work. In the high hormone phase consider taking on some carbs during your exercise so your body can access the nutrients on the spot.

2. Can we use the different stages of our menstrual cycle to our advantage?

Absolutely. I like to think that as women, we have this secret weapon called our menstrual cycle that gives us allotted times to work hard (in the low hormone phase), and then ease off or rest (in the high hormone phase). Whereas men, who have relatively constant hormone levels, may be more inclined to simply work harder and harder until they burn out.

Many women find exercising immediately before or while on their period painful, due to cramping and other side effects, so while it is uncomfortable, take it a little easier. As soon as those painful days are over, really maximise the low hormone phase as much as possible. This is when you will feel stronger, have more energy and take longer to fatigue. You will be able to hit your top end speed in interval sessions, really push up those hills or go for that PB. Your body will be able to perform and recover well. This usually carries on throughout ovulation.

Into the high hormone phase, look to performing lower intensity sessions such as long or short easy paced runs, or easier gym workouts. As you get closer to your period, take advantage of some good rest. If you want to really utilise this time, consider performing simple, static drills to work on correct running technique.

I’d encourage all women who exercise to really get to grips with their cycle. Track your monthly symptoms to establish how your cycle looks - everyone is different and they range in length so the classic ’28-day’ example might not be the same for you. There are some brilliant apps out there at the moment which you can use to help track. Try FitrWoman or my personal favourite, Wild.AI.

Cycle Day 4 - Smashing a postpartum PB

3. Can exercise improve symptoms such as PMS or period cramps?

There is some research that suggests that regular exercise on the whole can improve PMS symptoms. I believe it is a balance and learning what works for you. If you can manage an easy 30 - 60 min run whilst experiencing PMS or cramps then you will very probably feel mentally better afterwards. Many women find that the endorphins from exercise lessen the symptoms. But it’s not for everyone. I have heard current olympic athletes speak about how they have to completely rest when they get their period because their cramps are so bad. There are no prizes for slogging out 5k when you feel rough. If you aren’t sure give it a try and see how you feel.

Cycle Day 1 - Relieved to have finished Goodwood Running GP Half Marathon

4. Why do you think many women are still reluctant or embarrassed to talk about their menstrual cycle with coaches etc?

I think many of us have been brought up in a society where periods are seen as dirty and a taboo subject. The knowledge about menstrual cycles and exercise has really only been developed in the last 10-15 years. Particularly when it comes to our menstrual cycle and sport, the two never went hand in hand. Now many female athletes, female and male coaches are actively building training plans around menstrual cycles, but we are still miles from where we should be.

5. How has increasing your awareness about your menstrual cycle been useful for your own running?

I think for me personally, the biggest change in my running and of the clients I coach is the mindset this way of training creates. When I used to have an ‘off’ week, usually before my period, I would still go out and churn out the miles, even though I felt awful, and I would more than likely give up part way through my session because I felt downbeat about my slower pace. Now, when I’m approaching my period I actively look to other things to improve, such as flexibility, running form, or I just take a really good break and get lots of sleep. I can fully appreciate that my body is busy doing it’s thing and I need to respect that.


Thank you so much to Emily for providing such detailed advice - I hope it will help fellow female athletes to understand and adapt their running around their own menstrual cycles too! For more information, you can visit her website or follow her on Instagram @wisewomeninsport.

To read more of my previous blog posts about postpartum running, click here. Don’t forget to subscribe to be the first to know about any news and updates, just enter your email address at the bottom of the page. Thanks!

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