Struggling to burn belly fat? It’s time to take a closer look at your menstrual cycle

Hormones control more than just your emotions.

But it’s not just our motivation and ability to work out that’s affected by our menstrual cycles, it’s the results we see from training that could be impacted, too.

A study into sport, exercise and the menstrual cycle from 2016 revealed that over 41% of women feel that their menstrual cycle has a negative impact on exercise training and performance.

Our periods messing with our training plans is more than just a feeling, it’s a biological fact, and it’s all connected with the four different phases of the menstrual cycle.

More than just ‘on’ and ‘off’

Taken at face value, it would be easy to assume that there are two parts to any woman’s cycle – when she is on her period, and when she is not.

However, there are actually four phases to the menstrual cycle and each one could have a slightly different effect on our bodies and consequences for our exercise goals.

The four phases of a woman’s menstrual cycle are:

• Menstrual phase
• Follicular phase
• Ovulation phase
• Luteal phase

"A normal cycle is 28 days from the start of one menstruation till the start of the next," clinical director Dr Alex Polyakov explained to body+soul.

"Ovulation takes place 14 days before the onset of the next bleed, which is day 14 of the cycle."

When it comes to our menstrual cycles, oestrogen and progesterone are the main hormones that are produced by the ovary and these fluctuate widely throughout all four stages of the cycle and could also have an effect on how much we benefit from exercise.

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Progesterone and your work out plan

Although he emphasised to us that the topic of the menstrual cycle in relation to the effectiveness of exercise is ‘under-researched’, Dr Polyakov also said that it is the hormone oestrogen that could help when trying to lose weight or build muscle.

The opposite of this are the phases of our cycle where we are producing progesterone, as this is when we will find it hardest to burn fat – no matter how hard we work at the gym.

"It is generally believed that increased oestrogen, compared to progesterone, may improve exercise performance and facilitate a reduction in fat volume and increase in muscle mass, Dr Polyakov said.

"It is also generally believed, but the evidence is very limited, that progesterone has the opposite effect.

"Therefore one would expect more benefit from exercise in the first half of a cycle, compared to the second half."

So, while the cramps, discomfort and pain experienced just before or during a period in the ovulation and luteal phases might rule hitting the gym out all together, there are other phases of the menstrual cycle where working out isn’t just easier, but might yield better results too.

Making your menstrual cycle work for you – and your muscles

Le’Nise Brothers, a registered nutritionist, mBANT, mCNHC, women’s health, hormone and menstrual cycle coach explains: "When we understand what’s happening to our body during each of the four phases of the menstrual cycle, we can adapt our exercise and our expectations accordingly.

"For example, the rise in oestrogen levels after menstruation finishes, during the early follicular phase, can contribute to increased energy levels that can support higher intensity workouts.

"What makes the rise in oestrogen different in this phase from the rise in oestrogen that occurs after ovulation, is the pre-ovulatory rise in testosterone. Testosterone means it can be easier to put on muscle during this time of the menstrual cycle."

So, this could mean that in the first days after our periods, when we’re feeling stronger and more energetic again physically, not only will we feel like working out more but we’re also more likely to train harder, for longer and potentially even see better results – especially if you’re trying to build up your muscles.

"A 2014 study looked a strength training in two groups of women: one group was in their follicular phase and the second group was in their luteal phase. The results of the study, suggest, despite a small sample size, an increase in muscle strength and diameter in the follicular phase when testosterone and estrogen are highest, compared the luteal phase when they are relatively lower," Brothers told body+soul.

"This rise in energy that occurs after we finish our periods continues all the way until around seven days before our periods begin, when oestrogen and progesterone start dropping."

So, that feeling of sluggishness before you come on your period? Yup, we’re all prone to it and it’s not just our minds failing to find the motivation to hit the gym either – it’s a physical change in our bodies at this stage of the menstrual cycle.

Sydney-based naturopath, lecturer and researcher Rebecca Warren explained: "We do tend to see a drop in muscle strength around ovulation so laying off the heavy weights during this part of your cycle and going for something a little less strenuous like a walk or something more cardio-based might work better for your body during this time."

While we might not be able to hit peak performance during this phase of the menstrual cycle, Brothers said that after your period you could be more likely to burn fat – so this is the best time to sign up for those high intensity gym classes.

"After we ovulate, the second rise in oestrogen contributes to an increase in energy expenditure. There aren’t many definitive studies in this area, however the few studies we have seen suggest that oestrogen and its rise post ovulation can promote endurance performance by altering carbohydrate, fat and protein metabolism," she said.

"Oestrogen promotes glucose availability and uptake into type I muscle fibres, which can be beneficial during short, HIIT type workouts. This can reduce reliance on muscle glycogen during exercise and help burn more fat."

Warren also pointed out that if you’re monitoring your weight, you shouldn’t be downhearted by a rise in the number on the scales before your period – because this is perfectly natural and usually not connected to anything you are doing wrong with your diet or exercise.

"It’s quite common for a woman’s weight to be at her highest in the late luteal phase through to the first day of her period (i.e. from day 24 onwards), but this is typically associated with a change to fluid distribution in the body rather than body fat," she said.

"Plus, we do have to remember that metabolism is a combination of things, including nutritional status."

Embracing the changes and noticing a difference

Peaks and troughs in our hormones are normal and natural: "Many of my patients tell me in the clinic, they ‘just know’ when their hormones are affecting things," Warren said.

However, she also explained that there are certain conditions or circumstances, such as unusually heavy periods, that not everyone will experience but will make it harder for some women to lose weight, build muscle or regularly take part in high intensity exercise:

"Polycystic Ovarian Syndrome (PCOS) significantly influences a woman's hormones and her ability to lose weight, as does thyroid dysfunction," she said.

"These hormones can then alter the menstrual cycle which further compound the problem. Also, if a woman is experiencing significantly heavy periods and losing a lot of blood, this can result in a drop in her haemoglobin levels. This is a protein that helps our red blood cells transport oxygen around, so women can experience breathlessness, an increase in fatigue, less ability to ‘push themselves’ and longer recovery times just after they bleed."

Knowing your version of ‘normal’

Warren believes all women should track their periods, to help you note what are regular, natural fluctuations in your menstrual cycle and where there might be inconsistencies.

"The main thing to consider with our hormones is it’s all about balance and consistency. If you’re not tracking your menstrual cycle, start! Different symptoms happening at different times can tell us about what might be happening and will help you to identify patterns. And because every woman is different, you can start to use your own information to determine what you need to do/be aware of," she said.

So, while there’s no hard and fast rule when it comes to what exercise to do during each phase of your menstrual cycle, what is for sure is that all women are different – but our periods potentially messing with our exercise routine is not.

Changing up workouts to best meet the natural fluctuation of hormones and our bodies might not be for everyone, but it will certainly work for some – and that includes me reader.

"It’s important to take it a bit easier in the week just before your period," Warren said.

"Some women may also recognise that they have to pull back a bit of intensity around ovulation and that’s ok too.

"Like our hormones cycle over the month, so too should our exercise patterns."

The best piece of advice when it comes to making the most of your menstrual cycle and keeping fit? Listen to your body.

If you are affected by anything mentioned in this article, concerned about your periods or worried about your hormones or menstrual cycle, chat to your healthcare practitioner or visit your GP.