The Menstrual Cycle and Training for Fat Loss

The Menstrual Cycle and Training for Fat Loss

Presuming that circamensel rhythm is regular and that you are not using certain types of birth control, each month your body goes through its menstrual cycle. In order to successfully complete each cycle your hormones naturally fluctuate. What many ladies don’t know is that manipulation of training around these hormones many positively influence your fat loss goals if you approach it correctly.

(Note: I appreciate that menstrual cycles vary from month to month (phase variance) and from woman to woman but for the purpose of this article we have used standard timelines)

In this article I aim to break down the information you need to know in order to successfully plan fat loss and conditioning strategies around the menstrual cycle. You’ll learn:

  • What are the phases of menstruation?
  • How to adapt your training around the cycle to benefit fat loss and conditioning

What are the phases of menstruation?

  1. The Follicular Phase: Days 0-14

This phase follows on from the previous menstrual cycle and starts after the unfertilized egg causes the uterus lining to break down. It is called the follicular phase as follicle stimulating hormone (FSH) increases in order to stimulate the follicles of your ovaries to mature. This occurs as a result of signalling from the pituitary gland.

During this phase estrogen also starts to rise, potentially bringing a boost of energy that can often improve your mood too. Typically, body temperature and progesterone levels will remain static throughout this phase.

  1. The Ovulation Phase: Day 14

During this phase you’ll get a peak in estrogen. Subsequently the pituitary gland will trigger an sharp increase in luteinizing hormone (LH), causing the release of the egg from the follicle. Here you’ll find an increase in body temperature which will continue into and throughout phase three. Androstenedione and testosterone reach their peak prior to, or at the time of ovulation.

  1. The Luteal Phase: Days 15-28

This phase sees high levels of peak progesterone and estrogen (lower than the peak in the follicular phase but nevertheless high). These hormones aim to incite ovulation and prepare a suitable environment for a fertilized egg.

During this phase the uterus lining continues to become thicker. If the egg is not fertilized, the uterus lining degrades and hormones fall back to normal. However, the increase in progesterone also means that basal body temperature remains elevated.

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So how can you adapt training for fat loss?

The Follicular Phase

As you can see above, estrogen and progesterone fluctuate greatly during a cycle. As well as controlling reproductive function, both of these hormones can influence how energy is stored- this is largely due to their influence over insulin and cortisol.

During the follicular phase you’ll find that you have a greater tolerance for foods that promote an insulin response and a higher likelihood that your body will turn to stored glycogen as a substrate, so higher levels of carbohydrate will typically work well. It is common to find a decline in resting metabolic rate in the follicular phase, but coupling higher intensity weight training and cardio exercise will help with fat loss and also assist in adding muscle.

Conversely some women find that long distance exercise at a low intensity has just as much of a positive effect on fat loss. During this phase you will better tolerate pain and will typically find increases in endurance and performance.

The Ovulation Phase

During this phase, estrogen may positively influence post-damage repair processes through activation and proliferation of satellite cells (important for the hypertrophy response), therefore weight training is highly recommended during this phase. The increase in lean mass gained from this type of training will have a positive effect on your metabolic rate and potential for fat loss.

However, whilst you may still feel strong due to peak testosterone levels, the increased levels of estrogen and progesterone may also increase joint laxity, therefore a slightly more cautious approach to exercise choice and technique would be recommended- focus on weight-based exercise that is safer and allows full control over technique.

The Luteal Phase

During this phase there is a reduced reliance from glycogen as a substrate meaning that there is a potential increase in fat oxidation as fuel. Additionally, as progesterone peaks during this phase and there is also another increase in estrogen, it is recommended that training intensity is reduced somewhat and the main focus on the training be around lower intensity-longer duration type protocols.

Furthermore, the increase in basal body temperature may increase cardiac strain and subsequently time to exhaustion, meaning higher- intensity exercise will not be as comfortable. Be aware that your serotonin (and also possibly your mood) will be low, meaning a potential increase in cravings for sugary foods.

As insulin sensitivity is lower in this phase (and of course training will be of a low intensity), it is important to try and control carbohydrate intake as much as possible.