Tuesday, October 18, 2011

How Birth Control & The Menstrual Cycle Affects Weightlifting

Huzzah!

After reading my article yesterday about soy and its estrogenic effects on the human body, fellow lifter/eater Dana asked me to do some research on birth control and how it may or may not affect a females weightlifting progress (did I mention Dana is a record-holding powerlifter?) I am clearly no expert on the subject of birth control, but in this article I will do my best to present the research I find to you.

Lets get started.

Birth control involves one or more actions, devices, sexual practices or medications followed to intentionally prevent or reduce the likelihood of pregnancy or childbirth. The three main routes of birth control to prevent or end pregnancy include contraception (the prevention of fertilization of the ovum by sperm cells), contragestion (preventing the fertilized egg from implantation - morning-after-pill), and the chemical or surgical induction of abortion of the developing embryo/fetus.

The Pill - combined contraceptive pills have two hormones - an estrogen and progestin. They stop the release of the egg (ovulation), and also make the lining of the uterus thinner. (MNT)

Contraceptive patch - a transdermal patch applied to the skin. It releases synthetic estrogen and progestin hormones. They have been shown to be as effective as the combined oral contraceptive pill. The "Patch" is worn each week for 3 consecutive weeks, generally on the lower abdomen or buttocks. The 4th week is patch-free.  (MNT)

El patch.
First off, it has been surprisingly difficult to find more than a handful of studies that have tested the effects of BC on a female weightlifters body. And the research that is available is somewhat inconclusive. Most of the studies have been conducted to test the effects of menstruation on an athletes performance and both sides have presented arguments. On the one hand, there have been Olympic level athletes who have won gold medals during menstruation periods, but most of these athletes were runners or endurance athletes. On the other hand, studies have reported that athletes have experienced cramps so sever that they are unable to perform at their normal levels.

These studies have also reported an increase in muscoskeletal and joint injuries, there has not been a definitive answer on this, however. A theory that has been gaining traction has pointed out that the increase of the hormone "Relaxin"  during menstrual cycles may be the culprit. Relaxin relaxes (go figure) the joints and connective tissue in a woman's body, so this may be the cause of increased injuries during menstrual cycles.



It has also been difficult to conduct studies on women's birth control cycles and how they relate to weightlifting, partially due to the various BC methods on the market, but luckily there has been one comprehensive study that has done the job. A study was presented at the annual Experimental Biology 2009 conference in New Orleans. The study found that women who used oral contraceptives experienced hampered lean mass gains while weightlifting.

73 healthy women, ages 18-31 were either assigned to a BC or non-BC group. Body compositions measurements were taken via hydrostatic weighing, in addition to blood samples before and after to measure DHEA, DHEA-S, and IGF-1. The results showed that the women who did not take BC pills gained 60% more lean mass compared to those taking the pills. While strength gains, arm and leg circumferences remained the same for both groups, The anabolic hormone levels of the non-BC were significantly higher than the BC group, and the DHEA and IGF-1 levels were also significantly higher.

Sadly, testosterone levels were not tested, that may have provided some clarity as to why the strength gains were similar for both groups. the BC group also had elevated levels of cortisol, which also helps to explain why the lean mass gains were lower than those in the non-BC group.


Love the message behind this poster

There is copious amounts of anecdotal evidence from female users of various contraceptive methods. Nearly all users of contraceptives report some sort of undesirable weight gain, even though they are actively participating in strength training and eating a clean diet high in protein. Based on what I have seen, those that use the DEPO shot have reported the highest amount of weight gain, some as high as 45lbs. Hormone levels can also be affected by introducing artificial hormones into the body, and some pretty crazy mood swings may ensue. 

Again, I am no expert on this subject, If you would like to share your experience with contraceptives and how it has affected your fitness, feel free to do so in the comments.


Sources:

  1. http://www.medicalnewstoday.com/articles/162762.php
  2. http://www.sciencenews.org/view/generic/id/43210/title/Science_%2B_the_Public__Birth_control_pills_can_limit_muscle-training_gains
  3. http://www.ncbi.nlm.nih.gov/pubmed/8013042
  4. Daly J and W Ey. Hormones and Female Athletic Performance. Women’s Sport Foundation of Western Australia, Inc., 1996.
  5. http://www.ajcn.org/content/90/5/1433.abstract 
  6. http://www.providence-health-plan.com/low-estrogen-birth-control/

3 comments:

  1. Very interesting article. I have no actual scientific evidence to add, but an interesting personal experience. I was taking the oral contraceptive, Yaz, for approximately 2 years and strength training using Jim Wendler's 5/3/1 program the entire time. Although I was making strength gains, they were small and inconsistent. Approximately 2 months ago I quit taking the medication and (with no change in training intensity or frequency) I have been hitting some mega PR's. Not only that, I feel like I have a ton more energy. As for body fat percentage I have never had it measured so I couldn't say, but I do feel like there has been some change in my body composition as well. Needless to say, I won't be going back to oral contraceptives any time soon.

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  2. Very interesting. I am 26 years old and had to have a hysterectomy due to illness. I currently take estrogen that is absorbed by the skin (evamist). I wonder if there is any research on that and the effects of weightlifting....I shall see, or if you can post here that would be awesome!

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  3. I think birth control does effect weightlifting. Here's my biased, non-scientific opinion. When I take rests from training without being on BCP I usually get stronger and heavier. When I take breaks from training while on BCP I lose lean mass and lose strength. BUT my boobs stick around better when I'm on BCP and lose fat. So does my lower abdominal fat.

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