One of my favorite, non-CrossFit women’s fitness blogs is Krista’s over at Stumptuous. She keeps an eye on all things dirty, heavy, real and womanly. She punches, lifts heavy weights, looks awesome and shares smart stuff. She brought my attention to a study regarding women on birth control pills and muscle building. This is an interesting topic actually and keeps us on track to remind ourselves that we have a gym full of women Getting-Some in the Challenge right now. Since birth control pills are exogenous hormones and since body composition (and daily strength) are controlled by hormones it makes duh! kind of sense that the two things would be interconnected. Still, this is not a topic that many researchers have tackled. Aimee Anaya over at Catalyst Athletics spoke to us at the Black Box Summit about the connection between the menstrual cycle and her strength. Aimee is a competitive Olympic Lifter and discusses the use of birth control pills to manipulate the timing of the menstrual cycle relative to competitions. Now, we might have our own personal opinions on that practise, but the fact is that reproductive hormones affect this sort of thing. I like to remind myself that competitive athletics is not always synonymous with health and wellness. Anyway, here is what the study found (OC stands for Oral Contraceptive):
The researchers found that:
- there were significant differences in lean mass gains (OC: 2.1±2.1% vs. non-OC: 3.5±3.2% / OC: 1.0±1.0kg vs. no-OC: 1.6±1.4kg, p<0.05). However, other muscle responses such as strength gains and arm/leg circumferences were similar between the OC and non-OC users.
- resting/fasting blood concentrations of the anabolic hormones were significantly lower in women taking OC vs. non-OC users throughout the study period. At the same time, plasma concentrations of cortisol (catabolic hormone) were elevated.
- those OC users had reduced DHEA hormone at the end of the training period. By contrast, the other participants’ levels did not change.
Conclusion
According to the researchers, “We were surprised at the magnitude of differences in muscle gains between the two groups, with the non-OC women gaining more than 60% greater muscle mass than their OC counterpart.” They added that even though the study has observed negative effects of oral contraceptive use on muscle gain in the context of resistance exercise training, “future studies are needed to help explain the reasons behind the results.”
Personally,even more so than the negative impact on strength I would like to see further study of the elevated cortisol levels. Cortisol is our primary stress hormone and is linked to all kinds of menacing health issues. Cortisol is catabolic which means it breaks down muscle. It is one of the primary reasons endurance athletes are not muscular.
CrossFitting Sisters, if you really care about your strength advances and your 1 rep maxes, match up your lifting to your menstrual cycle. Chances are you’ll see some patterns and decide you might want to schedule a personal training session or come to Open Gym for your 1RM deadlift some months. I promise a more manly post tomorrow.
Um, I do care about my 1RMs, but I’m not about to take birth control for that reason. Weird post, dudes.
I’d rather have reduced muscle gain than have to try to get through a CF workout while dealing with the health problems my OC helps me manage
Cassie, I think I didn’t make myself clear. I wasn’t suggesting that was a good idea, in fact the opposite, but all of the women I know who have been crossfitting for more than a year or two are very aware that their menstrual cycle affects their workout performance, especially on heavy lift days. My suggestion was to observe that connection if you are ready to look at your performance at that level of detail. I think it is especially important that women and their coaches are aware of the differences between men and women and the hormonal impact of the menstrual cycle. Not a common topic of discussion, but an important one for those women really focused on tweaking their performance.
I knew it! I really don’t pay that much attention to my workouts. I come in and do what they tell me and that is that. Having said that… When I really started eating better I became much more aware of my body in general. I do seem to think that workouts are “easier” at some points during the month than others. I also think sticking to the diet is MUCH easier at certain times of the month! Good post.
I have definitely noticed this connection and I find that just a few days before my period and throughout it I am noticeably weaker. As you suggested, the connection is not so much with lighter workouts or metcon workouts, but with very heavy lifting, I will not reach or even match a 1RM during that part of my cycle.
I started making sure my CrossFit Total attempts are at a certain time for this reason! I too, didn’t notice this until about a year after I started. Metcons suffer the week before; strength the week of. I’ve always been borderline anemic, so little changes make a big difference with me.
I gotcha! – makes sense. I’ve definitely noticed a difference for myself too and so far I just cut myself some slack at that point. I can understand it being a major factor for some though.
Fascinating. Thanks Jen. 60% greater muscle gain for non-OC group, quite a difference. Might I have the study citation? Couldn’t find it at Stumptuous site. Maybe I was distracted though by this statement: “hunger is not a global production problem it is a global justice problem.” (Jan 23rd)
I posted the link to the article which includes the official citation if you click on the word “study”.
Yeah-she is great.
I knew there was a reason my DL was plateauing! No more OC for me, I’m switching to Depo-Provera!
Ooo, I see it now. Thanks. Actually, that statement at Stumptuous site claiming hunger as a problem not of production but justice is awfully simplistic, to a student of economics.
I KNEW there was a reason for my 95lb press!!!!!
Add this to the very long list of reasons for avoiding OC. Thanks, Jen!