What is really responsible for an irregular menstrual cycle in female athletes

What really causes an irregular menstrual cycle in female athletes

Most of us will probably have heard about the female athlete triad and if not, I'm going to give you the shortest possible summary of this problem. Women who train too much, eat too little and have too low a body fat percentage stop menstruating, don't produce enough oestrogen and start to lose bone mass. I wrote a major paper on this topic as a student.

I was interested in the topic mainly because I had irregular periods and had suffered from amenorrhea (missed periods) frequently in my teens and twenties. But what confused me the most was that all the literature said that low body fat could be blamed for not having a regular menstrual cycle. Well, even though I wasn't fat, I definitely didn't have a visible six-pack at the time.

This made me wonder if I was really that messed up in the head (i.e. was I far slimmer than I thought I was in the mirror) or if there was more to the issue of amenorrhea than just being slim. Was I exercising too much? And is it perhaps even possible to get super lean and still continue to have a regular menstrual cycle? There seemed to be a lot of super slim girls who didn't have the same problems with their periods as I did. There had to be more than just body fat percentage involved.

As it turns out, there's actually more to it than just being slim. It's not simply the amount of body fat that alters ovulation and menstrual cycles. In fact, hypothalamic amenorrhea, which we athletes tend to develop when we no longer get our period (and which basically means you no longer have a cycle and no one knows why) is a real challenge for scientists. So far, the factors and processes involved have not been fully investigated.

What we do know, however, is that absolute energy balance is more important than body fat percentage for maintaining normal hormone production, ovulation and menstruation. In fact, it is quite easy to separate body fat percentage and reproductive function, as it has been shown that in some female athletes a normal cycle returns when energy expenditure is reduced, such as after an injury. This often happens long before a change in body weight or an increase in body fat percentage can be observed.

So if it is not simply the low body fat percentage that causes amenorrhea, what is it? The answer seems to be complex and is not yet fully understood by science, but I will do my best to make it as understandable as possible.

Problem #1: Body weight and not body fat

Body weight seems to have a greater influence than body fat on the menstrual cycle. When weight falls below 85% to 90% of ideal body weight, this usually results in amenorrhea regardless of body fat. I think this has a lot to do with the problems I personally had as a younger woman. I wasn't too thin, I was just trying to be too thin. However, you should remember in this context that the ideal body weight can vary significantly from woman to woman. My set point is around 60 kilos and when I get below 55 kilos I start to notice a lot of problems and irregularities with my cycle. For some women of the same body size, 55 kilos could be a perfectly healthy weight and their menstrual cycle could be unrestricted. It's all about YOUR body and YOUR ideal weight (from a health perspective).

Problem #2: When the workouts stop working

How hard we work on our fitness plays a huge role in determining how well our "girl stuff" works. When we exercise in a healthy way and expend more energy than we consume through food, we lose weight. This does not cause menstrual cycle problems for most women. However, for those athletes who tend to take their workouts and diets to extremes, this lifestyle can definitely have an impact on the menstrual cycle.

If you are pushing yourself to your limit with super long workouts twice a day and crazy metabolic conditioning workouts while eating very little to lose body fat, then you may have problems. The difference between intake and consumption is too great and throws the body off track. This increases the production of cortisol and other stress hormones, which in turn reduces the release of the GnR hormone by the hypothalamus. This results in low levels of Follicle Stimulating Hormone (FSH) and Leutinizing Hormone (LH), which in turn results in anuvolation, low estrogen, testosterone and progesterone levels and NO PERIOD.

Problem #3: Low leptin levels

Leptin also has an effect on menstruation. Leptin is a protein produced by fat cells and acts as a hormone on the reproductive axis. It is also the hormone responsible for making you feel full. Leptin levels are believed to correlate positively with body fat levels (i.e. leptin levels increase as body fat percentage increases), but lower leptin levels were also observed in bulimics and anorexics who exercised and/or had a lower calorie intake when leptin levels were compared to bulimics or anorexics of the same body weight who did not exercise or ate more. So your leptin levels don't seem to be firmly linked to your body fat levels, but more to the general availability of energy. And when leptin levels are low, so are GnRH and LH, making ovulation and regular menstruation less likely.

Here is an illustration of the mechanism of the menstrual cycle. As you can see, GnRH, FSH and LH are all essential for the initial phase (follicular phase). If the levels of these hormones are low, then things will go haywire.

What is the answer?

Since there are many other hormones and external factors that can cause an irregular menstrual cycle in female athletes, I think it's safe to say that it's not simply body fat percentage or workouts that are causing your cycle to go haywire. Amenorrhea in athletic women is more related to overall energy balance. If you suffer from an irregular cycle, you should ask yourself the following:

• Are you eating enough to support your activity level?
• Are you trying to lose fat by ramping up your workouts and restricting calories way too much?

If you're doing this, you're basically shooting yourself in the foot and you can expect your period to go crazy. You should also know that your metabolic rate and the release of hormones such as thyroid hormones, growth hormones and testosterone will also drop or stop completely. An irregular cycle, lack of progress in the gym and stagnant weight loss despite enormous efforts are your body's cry for help and rest.

The answer to this is not to just keep pushing yourself and ignore it all. Rather, the answer is to cut back a little. Of course, this isn't easy if you're the type of person who expects a lot from yourself. But trust me, don't waste months or even years fighting your body. It will win because it is smarter than you. The slower you lose body fat, the more muscle mass you carry around and the closer you stay to your body's ideal weight, the more regular your cycle will be and the happier, more cooperative and responsive your body will be in regards to your training.

References:

1. Ackerman, K., et al, "Higher ghrelin and lower leptin secretion are associated with lower LH secretion in young amenorrheic athletes compared with eumenorrheic athletes and controls." American Journal of Physiology - Endocrinology and MetabolismPublished April 1, 2012Vol. 302no. E800-E806 DOI: 10.1152/ajpendo.00598.2011

2 Comninos, A., et al, "The relationship between gut and adipose hormones, and reproduction." Hum. Reprod. Update (2013) doi: 10.1093/humupd/dmt033

3. Davis, J, Segars, J, Glob. libr. women's med, (ISSN: 1756-2228)2009; DOI 10.3843/GLOWM.10296

4 The ESHRE Capri Workshop Group, "Nutrition and Reproduction in Women." Hum. Reprod. Update (May/June 2006) 12 (3): 193-207. doi: 10.1093/humupd/dmk003

By Vanessa Bennington

Source: https://breakingmuscle.com/learn/what-really-causes-irregular-menstrual-cycles-in-female-athletes