Exercise and Fertility: What's your story?

[renavoo]

Hi Ladies,

While at the gym today (which I not so affectionately call the place of hell and torture), I started thinking...does exercising too hard reduce fertility?

I don't exercise too hard now. I've cut down how high I get my heart rate. Also, my SIL, who is pregnant, is constantly doing Zumba. So I think that the impact is probably relatively mild. However, I did a quick search that suggested that working out too hard does decrease fertility although we should be working out.

I thought I'd ask the community...does anyone have a story about how they changed their workout habits once they started TTC or once they were diagnosed with infertility?

My story is that I do the elliptical 3 times a week and I walk to and from work. My heart rate, according to those machines, used to be in the 160s range. Now, I've started to try to keep my heart rate down to 150 or less. I'm starting to gain weight because I've been eating the same amount (maybe a little more because I'm so upset about this infertility!) and exercising less strenuously. I'm not sure how strenuous is too strenuous and what my goal should be!!

Thanks for the stories!

[RosieL]

Nope! It's the opposite, exercise is good for fertility as far as current science knows. Until you get into the range of really low body fat (leading to ammenorhea), vigorous exercise is really good for you! I did a mini lit review on the topic and was surprised by the results. Mayo Clinic says don't exercise too much, and cites an article...but that article says the exercise RAISES fertility, reversing an earlier journal article that had had poor sample size (I think 12?). The pro-exercise article came out of the nurses health prospective study. I'll dig up those references if you'd like. 

I posted extensively (I think?) about it a couple months back in the 30-somethings thread. 

Disclaimer: I'm not a doctor. My information comes from google scholar searches, pubmed searches, and handy library access from my university.

[Sourire]

RosieL - wow those results are pretty surprising!

I have read that very intense and frequent excercise can lead to anovulation, and I assumed the effect was probably gradual (i.e. the more intense excercise you do, the greater the effects) so that even if you are still ovulating your fertility might be decreased depending on the level of excercise you are doing. The reason for this supposedly dates back to prehistoric times and the only time you would have to do really extreme and prolonged excercise would be in periods of intense danger (ex: running away from a huge forest fire)... and during that time is obvious that reproduction would not be convenient so your body shuts down its reproductive function in order to focus on survival.

However I have also read that for optimal fertility its necessary to do SOME excercise.. no excercise at all is just as bad as too much... the question is how much and how intense that excercise should be. One fertility expert recommends about 45 minutes a day at around 80% of your maximum heart rate.

Personally I am not a person who feels the need to excercise intensely (I'm underweight) so I try to do about 1 hour a day of mild excercise such as walking or gentle biking or yoga. Though I'm not pregnant yet so I can't say whether I'm at the optimal level or not.

[RosieL]

The problem with studies on exercise and fertility is that it's impossible to do controlled and blid trials, which would be the gold standard of experiments. But the prospective studies do a pretty good job of giving estimates with good statistical power. Seven hours a week of vigorous exercise was the cutoff for the study cited below, the most current I found in Feb. 

Rich-Edwards, J. W., Spiegelman, D., Garland, M., Hertzmark, E., Hunter, D. J., Colditz, G. A., et al. (2002). Physical Activity, Body Mass Index, and Ovulatory Disorder Infertility. Epidemiology, 13(2), 184.

This is from my earlier post on the subject: "The one paper (Rich-Edwards et al 2002) was from a large cohort study that actually found a DECREASE in infertility risk with every increse in weekly exercise time. I thought this was really curious, since the findings of this paper are in direct conflict with the conventional web wisdom. So I looked at the citations of that paper, and it's discussion of previous research. There were three studies that previously mentioned exercise and ovulation dysfuntion (the only infertility factor considered to be related to exercise). It looks like one study found the "over seven hours per week" increases fertility risk result. However that study (green et al 1986) only had 12 subjects in that category, whereas the rich-Edwards study had over one hundred." http://www.mothering.com/community/forum/thread/1295315/ttc-1-in-our-30-s-feb-2011-who-doesn-t-like-bajingo-juice/160#post_16264101

[rhiandmoi]

It's called Exercise Related Menstrual Dysfunction or Athletic Menstrual Dysfunction. For most women you would have to do really really excessive amounts of exercise to get there probably coupled with an eating disorder or exercising compulsion or full time athletic training at like super elite levels while on a restrictive training diet.

For me personally, exercising has not seem to have any effect on my fertility on my side of things. It helps make TTC more fun though! :)

[Silverbird]

Hi I had been wondering about this too having seen the >7 hours thing.  So people think as long as your a healthy BMI it wont affect it?

I've just got rid of the car so I'm doing 25 mins really hard cycle up hill, 40 mins medium cycling and like 10 mins no pedling down hill cycling three times a week for work and other cycling for lesiure.  presumably only the difficult cycling would count.  And what about gentel strolls, yoga etc?

[Sourire]

Rosie - it looks like we are saying more or less the same thing. Your study shows that fertility increases up to 7h of vigorous excercise, and the sources I was quoting recommend 45 mins a day of vigorous excercise for optimum fertility which isn't so far off from your 7 hours. 45 mins a day falls into the 2nd highest category in the study which happens to be the category with the best results.

I guess I was thinking of much higher levels of excercise being an impediment to fertility, which the study doesn't look at. For all we know, 95% of the people in the 7+ category might be doing only 7-8 hours of excercise so we can't know what happens if you are doing say 2 hours of intense excercise a day.

[RosieL]

Yeah, I think we're saying basically the same thing. Exercise is good, except for folks who start to get into the more extreme side. 

Starting Monday DH and I go back on to our triathlon training routine. Mile runs plus bodyweight exercises each morning (about 45 min) and an hour each evening (running, swimming, biking, or a run/bike). He HAS to do it, I'm going to do it with him because I like it, even though I didn't sign up for any races this year. If I see an iota of sign of annovulation, I'll dial it back. But my OB (a marathoner), midwife (awesome but not an athlete), and the research I've found say I'll be fine. I couldn't get down to less than 20%BMI unless I SERIOUSLY changed eating habits. I eat a LOT of meat and veggies. 

[renavoo]

Hi everyone!! Rosie, thanks so much for the reference!! That really relieves my mind (haha although I still don't particularly like exercise). :o) Therefore, I don't think I'll ever over do it. haha