Exercise-induced amenorrhea

“Being under about 45 and not having a period for years and years is a real medical problem. If medical issues are ruled out then increased calorie intake is always indicated. The risks of going amenorrheic from exercise are very significant. Female athlete triad, the osteoporosis can get so severe that you get fractures just from walking or exercising. “

I’ve been asked for information on Exercise-induced amenorrhea. So, here is what I have that I’ve read/listen to at some point; I put together everything from Lyle’s comments since before the making of his “women” book, to studies and articles that I have from trusted sources, the first and second links sums it up pretty well.

Female Athletes and the Menstrual Cycle by Matt Stranberg  from https://www.mattstranbergconsulting.com/








Lyle McDonald  “Body fat levels are at most permissive and it’s really more to do with energy availability. Think of this as calorie intake – exercise output. If it gets too low, the system shuts down. You’re eating enough to maintain normal menstrual function.”

“NB: Category 1 is a body fat issue, 24% or less.

Chapter 20: The Category 1 Dieter: Introduction

Over the next three chapters, I am going to look in detail at the issues that the normally cycling Category 1 dieter has to contend with as they attempt to diet to further degrees of leanness. Women in other categories certainly have to deal with metabolic issues and slowing fat loss but since there is no menstrual cycle to lose, women on BC, peri- or post-menopausal with or without HRT don’t have to worry about much of what the chapter will discuss.

Category 1 females in those categories will be discussed in their respective chapters although Category 1 women who need to diet down extremely can use the calculations in this chapter to determine how much fat they need to lose and how long their diet should be. And while you might think this would apply only to women on BC, there are increasing numbers of master’s female athletes entering physique or strength/power competitions so there may be cases where the peri- or post-menopausal woman needs to do the same calculations.

There is one exception to the above, as women with PCOS/subclinical hyperandrogenism, who usually show an extended cycle length (35+ days) can still lose their menstrual cycle completely during dieting. At that point, the issue relating to amenorrhea (discussed in Chapter 21) basically apply. But in all cases, any woman who is not in the normally cycling category will find Category 1 dieting templates in their respective chapters. They only need the calculations in this chapter to estimate their dieting time.

The Normally Cycling Category 1 Dieter
The normally cycling Category 1 dieter has a number of very specific issues, including the potential (if not almost inevitable) loss of their menstrual cycle. This is especially true if they are trying to achieve the lower limits of female BF%, around 10-12%. This typically includes physique athletes although the degree of leanness varies by the specific sport (bodybuilding and physique are generally leaner than fitness or bikini). Physique athletes also have to deal with the issues of peak week, the 5-7 days prior to their competition, and Appendix 2 will contain peak week information provided by natural bodybuilder, powerlifter and preparation coach Eric Helms.

But this doesn’t represent all Category 1 dieters and other athletes often need to reduce their body fat although usually for more performance-oriented reasons. Strength/power athletes in weight class sports often train at a heavier weight and body fat and then diet down at one point or another to make their class. They have a slight advantage over the physique athlete in that they don’t have to reach a specific level of leanness. They can also manipulate water weight slightly (1-5% of total weight depending on the sport) to make their weight class which means that they don’t have to lose as much total fat. I’ll provide a basic water manipulation schedule in Appendix 2 as well.

High-intensity performance athletes often compete at fairly low BF% but how lean they get depends on the sport. The key is being lean enough to optimally perform without having to diet so extremely or add so much training that performance is negatively affected. Endurance athletes, again depending on the sport, will often lean out prior to their competition phase. Runners are the ones notorious for trying to reduce their weight and BF% to the lowest degree although cyclists often do the same. Swimmers are less hampered by excess body fat as is rowing (although the lightweight class has a weight limit).

Even those Category 1 dieters who don’t have to get so lean that the loss of menstrual cycle is likely, there are still the issues of slowed fat loss, decreased metabolic rate, and preventing drops in performance and this presents a separate set of issues. The physique athlete primarily has to keep their fat loss moving without losing excessive LBM; the performance athletes have to do the same without hurting their ability to train effectively or perform well.

One Odd Category 1 Situation
There is also another Category 1 situation that I want to address briefly. This is the relatively lean woman who is not coming from any sort of training or exercise background and isn’t dieting for any other reason than wanting to lose weight. But there is a big problem in this group: their lack of any sort of exercise, especially resistance training, predisposes them to LBM loss. And that causes problems when the diet ends.

Not only do Category 1 dieters who aren’t training (especially resistance training) unlikely to improve their appearance to the degree that they would like, they are at a much higher risk of rebounding to a higher BF% than they started at. LBM sends its own independent signal of hunger to the brain and this loss will make post-diet hunger worse than it would otherwise be. Since resistance training also improves LBM gain when weight is regained, the approach taken by these dieters is very likely to cause them to end up with a higher BF% than they started as they will continue eating beyond their initial BF% until the lost LBM is regained (1).

Before considering attempting to lose weight/fat, I would strongly recommend doing at least a month or more of the beginner fitness program in the last chapter. At the very least, a resistance training program, even twice per week should be started with the diet for all of the reasons I’ve discussed in earlier chapters: increased fat loss, increased appearance and, in this specific case, to avoid a very real potential body fat rebound above starting levels. Dieting without resistance training for the Category 1 is likely to be a disaster with any other approach.”

Leptin in Human Reproductive Disorders

As a key hormone in energy homeostasis, leptin regulates neuroendocrine function, including reproduction. It has a permissive role in initiating puberty and maintaining the hypothalamic-pituitary-gonadal axis. This is notable in patients with either congenital or acquired leptin deficiency from a state of chronic energy insufficiency.

Hypothalamic amenorrhea is the best studied with clinical trials confirming a causative role of leptin in hypogonadotropic hypogonadism. Implications of leptin deficiency have also emerged in the pathophysiology of hypogonadism in type 1 diabetes.

At the other end of the spectrum, hyperleptinemia may play a role in hypogonadism associated with obesity, polycystic ovarian syndrome, and type 2 diabetes. In these conditions of energy excess, mechanisms of reproductive dysfunction include central leptin resistance as well as direct effects at the gonadal level. Thus, reproductive dysfunction due to energy imbalance at both ends can be linked to leptin.

Chou SH-H, Mantzoros C. Leptin in human reproductive disorders. Journal of Endocrinology.”

“Being under about 45 and not having a period for years and years is a real medical problem. If medical issues are ruled out then increased calorie intake is always indicated. The risks of going amenorrheic from exercise are very significant. Female athlete triad, the osteoporosis can get so severe that you get fractures just from walking or exercising. “




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