Women's Cycling

Female club athletes and exercise induced amenorrhea

I’ll start by making it clear I’m not offering a full set of ANSWERS in this post, but instead exploring the issue, and mainly asking QUESTIONS. The comments are there if you’ve got the answers!


Exercise induced amenorrhea, put simply, is the name given to a lack of menstruation, as a result of low body fat percentage or repeated stress on the body.  There are two types of amenorrhea – primary (caused by genetic conditions) and secondary (caused by stress, weight loss, or exercise).

Exercise induced amenorrhea is often put down to eating disorders or low body fat, but this is not always the cause, and intense exercise, even with adequate eating, can be the cause.

Generally, the advised method of restarting menstruation, is to reduce exercise, and improve diet.

The concern with this condition is not just that it can affect long term fertility, but that it signals a lack of Estrogen and Progesterone. These hormones also regulate bone development and health. Long term amenorrhea can result in osteoporosis in later life, or brittle bones – causing stress fractures. In girls before and during puberty, amenorrhea can stunt development, and really, really does need to be addressed – in this post I’m mainly talking about adults.

The scientific explanation is thus:

It [Ammenorrhea] is caused by alterations in gonadotropin releasing hormone (GnRH) production from an area of the brain known as the hypothalamus.  GnRH is secreted in a pulsatile fashion and causes the pituitary to release luteinizing hormone (LH) and follicle stimulating hormone (FSH).  LH and FSH regulate the ovaries, hormone production (estrogen and progesterone).  These hormones then regulate the menstrual cycle, aspects of bone development and secondary sexual characteristics such as breast development and female fat and hair distribution.  With intense or excessive exercise, the GnRH secretion is abnormal resulting ultimately in abnormal ovarian function and hormone production.

It all sounds rather serious – the kind of problems you would expect in the pro field, where the sport is number one priority, and athletes will take risks to be at the top of their game. Lets be honest, not many pro triathletes or road cyclists have a lot of fat on them.


But would you expect exercise induced amenorrhea in club athletes? 

I started running when I was at university, I was on the pill, which controls your hormones, so I never noticed any changes. Then I came off the pill, and didn’t have a period for, I’m guessing around 18 months.

After that 18 months, I went to the doctor, who ran some hormone tests, and confirmed that mine weren’t that of your average female (not enough estrogen, too much testosterone, a common side effect of training in women) – so I went back on the pill, and a normal cycle returned.

I will add, during the hiatus, I was lighter than I am now – and I followed a fairly restricted diet, so for all I know, coming off contraceptives might result in a natural period, but I have no idea (and I’m not about to risk trying that..)

I’m the one in the middle.. have a bit more body fat these days

I asked the doctors questions about amenorrhea, and bone density, osteoporosis, and fertility. I was reassured that as contraceptive pills contain synthetic oestrogen/progesterone my hormones were regulated and thus I had enough of the required hormones to be healthy. In terms of fertility, there was nothing wrong with my ovaries, and ovulation can be induced if I ever wanted to conceive. I’m sort of 80% reassured by all this, and by the fact I am not as light as I was in the picture above.

Of course, I didn’t start writing a post to tell you all about my own menstrual cycle. It’s not something I’ve talked about to a lot of people so kind of a big deal putting it on the interweb, but I couldn’t really write this post and call myself ‘my friend’. What concerns me is that I’m in no way a pro athlete, obviously I’m more dedicated than your average Joanne who likes to ride a bike or jog, but once you get into ‘club/local racing’, I’m really very average.

I’ve only ever discussed all this with 4 other women athletes:

  • One didn’t have periods, but was greeted by the arrival of one after she stopped training. We actually both found this reassuring, I think – it meant they come back.
  • One is on the pill, and still has no periods.
  • One, who used to be a very high level, professional athlete, told me she’d never met a female athlete who had periods without the pill, and not to worry about it.
  • One, who pursued the issue, changed her diet, and managed to get them back.

Only one of the women above was competing at a professional level.

This said, emedicineheatlth tell me: “more than 8 hours of vigorous exercise a week may cause amenorrhea. A moderate exercise program may restore normal menstruation.”

To be honest, for a semi-competitive club athlete, 8 hours isn’t very much. Say you ride 3 hours on Saturday, run for an hour on Sunday, that only leaves 4 one hour sessions in the week. You don’t need to be exercising that excessively for this to happen.

A quick search online shows me that this is in no way a selection of isolated cases – comments on this (admittedly weight loss focused) forum show that a lack of menstruation is seemingly very common in exercising women. Not only that, but most of them have a lot of questions, and no answers.

I just went to the gyno last week for the same thing. He said it was fine as long as I weighed enough and got enough calcium, but when I wanted to have kids (in the far future, as I’m 17), I’d have to ease up on the running and put on a few pounds. I winced at that idea, but then I realized that you gain like crazy when your pregnant anyway so who cares if you gain a little for a couple months before conception? He said most girls who run at a college level don’t have a period. I guess it’s more normal than I thought. Hope that helps.


I haven’t had my period since late 2004, the gyno is attributing it to low body fat and said I need to put on weight to help it come back. Like some other posters in this thread, I balked at that idea. I also know that I do not want to be put onto birth control to “force” a period. Does anyone know of any alternative medicine/holistic treatments for amenorrhea? (other than weight gain?). Does anyone have a knowledge of vitamins and herbs? I never really like taking medicine for illnesses…

The honest answer, if the problem is caused by exercise or low weight, is to gain weight, and exercise less. However, I doubt that many women who train enough to alter their hormonal make-up are all that keen to sit back, take a break, and gain some body fat. The alternative is to go on the pill, which supplies your body with ‘normal’ hormones.

How would doctors treat exercise induced amenorrhea? 

This study asked 159 members of the American Medical Society for Sports Medicine (AMSSM) what they would prescribe – 56% of them practiced sports medicine, and 32% practiced family medicine.

The study was carried out to try to address the problem, stating:

“Optimal treatment for exercise-associated amenorrhea remains controversial, reflecting limited data on the therapeutic effects of hormonal or nutritional intervention in the prevention of osteopenia”

The conclusions were:

Sex steroid replacement was endorsed by 92%, calcium supplementation by 87%, increased caloric intake by 64%, decreased exercise intensity by 57%, weight gain by 43%, and vitamin supplementation by 26%. These findings suggest that sex steroids are used commonly to treat amenorrheic athletes, despite the paucity of data demonstrating their efficacy in preserving bone mass in this disorder. Further research is needed to define the benefits of estrogen alone or in combination with nutritional intervention for preserving bone mass in female athletes.

This is of course one study, with one set of results, there are plenty more.

My own advice for women in this situation, is not to ignore the problem 

It is easy to let months float by, and to do nothing, another month turns into six, which in my case turned into 18. I’m not sure the pill is the ‘answer’, synthetic hormones aren’t real, and your doctor might tell you differently. Personally, I’m tempted to go back to the doctor, and repeat the tests now I don’t ban myself from dairy and carbs.. Whatever your situation,  you won’t know until you ask.

If you get a good answer from one, or if you’re an expert with lots of answers, please let me (and the 100s of women posting on forums) know what the answer is… 


I'm an NCTJ Journalist and work at Cycling Weekly. Previous to this, I was the Editor at Total Women's Cycling. I've also dabbled in marketing and copywriting - having been Marketing Coordinator and Social Media/Content Editor at Evans Cycles. My first job was working on a local newspaper.  I've written for a variety of titles on a freelance basis, too. I got into cycling when I entered my first triathlon in 2010. I now race crits, road races, time trials, and do a lot of track training for not very much track racing.

4 comments on “Female club athletes and exercise induced amenorrhea

  1. ok so I am a 15 year old girl who is 5’4 and weighs 103 pounds. I eat normally but my metabolism keeps me small. The last two periods I had were both off schedule and were very light. I was suppose to get the next one a few weeks ago, but still no signs. I have never had sex, but I am buying a pregnancy test soon just to make sure im not somehow pregnant. I have never taken any kind of birth control. For about a year, I was use to not really exercising anymore than the occasional walk or something else small. In the end of January I got onto the Track team. My period in February was late and light. I guess you could say that I have been “hard core” working out. Along with the lack of a menstrual cycle, my hips have been killing me. I have read that amenorrhea can cause problems with bones. So I have a question for you. Do you think there is a possibility that I have exercise-induced amenorrhea? or do you think that there is something else wrong? If you think that I have the amenorrhea, then what type of doctor should I talk to?

    • Hi Kimmy – sorry you’re struggling with confusion over all this. You are very light, but if you’re not dieting and this is natural for you then that isn’t a problem. I think the best thing you can do is visit your GP. Not all GPs are totally ‘up’ on exercise induced ammenorrhea, but if you go, explain the symptoms so far, and tell them you think this could be the cause, they will hopefully send you to have a hormone test, and a test to see how your ovaries are functioning. Then when the results come back your GP should be able to guide you through what the causes could be. If you had healthy periods before, and they stopped when you picked up the exercise, it does sound like this could be the cause. That’s nothing to worry about – but a trip to your GP will tell you if you need to take any action, and hopefully set your mind at rest, too. Michelle

  2. This is happening to me too! I am not a pro athlete obviously, but I run 35-42 miles a week, along with calisthenics and weights 6/7 days of the week. I keep a very healthy diet, eat enough, don’t stay away from dairy(other than milk), and I am pescatarian. I haven’t had my period in 2-3 months, and the last few I had were progressively lighter. My periods used to be pretty normal while I was running as well, about 7-10 days long with 2-3 days of heavy flow and the rest at a moderate flow….this is so frustrating. It might be because I hit 15+ miles in one run lately and have been continuing to add mileage. I love exercising and I definitely don’t want to stop and lose all the strength I’ve gained. Am going to the doctor later this week to hopefully find a solution. Taking hormones is also not too attractive…any advice??

    • I should add I’m 5’4 and 114 pounds, soooooooo idek. I’v always had fast metabolism and been thin, I would say I’ve gained weight since exercising regularly(muscle mass).

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