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Menstrual Cycle, Exercise & Weight Loss, All you need to know!

From emotional status to fluctuating energy levels or varied appetite, it's no surprise how much your menstrual cycle can have an impact on you, your training and your weight loss goals. Despite being unable to relate as male personal trainer, over two thirds of my clients are female. Therefore I thought I should take the time to better understand the menstrual cycle and it's subsequent effects on training. Do you want to better tailor your training and goals to your menstrual cycle? Then you're in the right place!

So how does your menstrual cycle impact exercise and weight loss?

The menstrual cycle can vary from woman to woman. Regular cycles range from 21 to 40 days with an average every 28 days. During this time the menstrual cycle can be broken down into four key phases; Menstruation, Follicular, Ovulation and Luteal. These different phases can impact on how you feel and therefore impact both your training and goals.

Menstruation (Day 1 to 7)

The menstrual stage is the first stage of the cycle and is when you get your period. On average this lasts between 3 to 7 days but this is individual with some woman having longer periods than others. This phase starts when an egg from the previous cycle isn't fertilised and pregnancy hasn't taken place.

During this phase you may experience some of these period symptoms; (Archer, 2006)

  • Cramps (Dysmenorrhea)

  • Headaches & Migraines

  • Persisting Pelvic Pain

  • Tiredness

  • Mood Swings

  • Bloating

  • Irritability

There has been an increased amount of research on the impact of the menstrual cycle on exercise, although the results from the research is contradictory. What is known is the hormones oestrogen and progesterone are at their lowest during menstrual stage. There is a concept that oestrogen can have a strength enhancing effect, therefore when oestrogen levels are reduced this has a negative impact on strength levels.

Follicular Phase (Day 6 to 14)

There is some overlap between the follicular phase and the menstrual phase. During this phase another hormone is released also known as follicle-stimulating hormone (FSH) and stimulates the ovaries to produce small sacs (follicles) which contains an immature egg.

During this phase there is a surge in the hormone oestrogen. Regarding the concept that oestrogen has a strength enhancing effect, during the follicular phase, there is the greatest capacity for developing muscle strength.

Ovulation Phase (Day 15 to 17)

Ovulation happens right in the middle of your menstrual cycle, so this would be around day 14 in a 28 day cycle. It only lasts around 24 hours after which the egg will either die or dissolve if it isn't fertilised. The rising level of oestrogen triggers the release of luteinizing hormone (LH) and this is what starts the ovulation process. During this phase the mature egg is released by the ovaries heading towards the uterus. This is when you are most fertile and at the highest chance of getting pregnant.

At the end of the follicular phase and right before the ovulation phase you tend to have the highest levels of oestrogen.

Luteal Phase (Day 18 to 28)

The luteal phase lasts between 11 to 17 days with an average length of 14 days. After the egg is released in the ovulation phase it'll change into the corpus luteum, releasing more hormones. This is mainly progesterone and some oestrogen. This rise in hormones aids your uterine lining, keeping it thick and ready for a fertilised egg to implant. If you do get pregnant it's the release of the human chorionic gonadotropin (hCG) hormone that a pregnancy test will detect. Another hormone that helps keep your uterine lining thick. If you don't become pregnant, the corpus luteum will reduce and be resorbed and your oestrogen and progesterone levels decrease. This causes the onset of your next period. It is the shredding of your uterine lining during your period in the menstruation phase.

If you don't get pregnant, you may experience premenstrual syndrome (PMS) which may include the following symptoms;

  • Bloating

  • Breast Swelling or Tenderness/Pain

  • Mood Changes

  • Headache

  • Weight Gain

  • Food Cravings

  • Trouble Sleeping

  • Changes in Sexual Desire

During the luteal phase the increased progesterone is the likely cause of an increased basal metabolic rate and calories burned whilst sleeping. This can equate to an average overall increase of 90 - 280 calories per day. The majority of woman who are looking to lose weight may track their calories or follow a diet in order to achieve a calorie deficit. When you hit the luteal phase in the menstrual cycle due to this increased requirement for energy you may have an increased appetite and develop certain food cravings. With the best intentions of sticking to your diet or recommended calories you try and fight against your increased appetite. Unfortunately a hard truth for most, when you do give in you're more than likely to binge and overeat as a result. This may be a common cause of why perhaps you notice weight gain at certain points in the month.

What does this mean & how does this apply to me?

Put simply the four phases in the menstrual cycle can be split into oestrogen dominant phases (follicular and Ovulation) and progesterone dominant (menstrual and luteal). This plays a significant role in how you train and impact you achieving your goals.

Once a new cycle begins and you start your period, both oestrogen and progesterone is relatively low. You're likely to experience tiredness, cramps, mood swings and various other symptoms. Therefore it's important to consider your training volume and intensity. Whilst you feel uncomfortable, tired and irritable perhaps reduce the load, increase your rest days, shorten your sessions or adapt your exercises in that initial week of your menstrual cycle.

As you move through into the follicular and ovulation phases, the middle two weeks of your menstrual cycle, progesterone remains low and oestrogen increases. You'll find that you'll have more energy and motivation to exercise. This is a great time to look to increase the intensity of your workouts, focussing on your strength and cardiovascular fitness. You should feel more able to set new personal bests and really progress your training.

As you enter the final phase of your menstrual cycle the luteal phase, oestrogen will start to decline and progesterone will be increasing again. During this time try not to put to much pressure on yourself and fight against your body. Perhaps increase your calories slightly during this phase to combat those food cravings, start to reduce your intensity in preparation for the next menstruation phase and the start of the next cycle. You can focus on other things such as exercise technique rather than strength training.

Important note!

As you can see your hormones fluctuate continuously. It's important to remember if you're using scales as one of the methods you use to track progress, not compare week to week. Your body's response to the hormone changes during your menstrual cycle will differ each week. Instead you want to compare week 1 of your menstrual cycle to week 1 of the next cycle, week 2 to week 2 and so on. This can give you a better understanding of what's happening during each phase of your menstrual cycle. This is the same for your workouts. It would be disheartening to compare a week of higher intensity workouts to a shorter less intense session you completed a week later because you're at a different stage in your menstrual cycle.

Last thoughts

It is important to remember that every women is effected differently by their menstrual cycle and even each cycle it's self can be different. It is a good to be aware of how your body changes across your menstrual cycle and how it could effect your exercise. Start tracking your cycle and make note of common symptoms you begin to notice. In time you will be able to develop a better understanding on how you feel and use this to tailor your training more appropriately. You will no longer walk away from sessions feeling demotivated and disheartened.

If you would like help with any of the above or have any questions, don't hesitate to get in contact via the website or through social media including Instagram and Facebook.


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