Women’s Training & The Menstrual Cycle: What the Science Actually Says | Lauren Colenso-Semple, PhD

**Dr. Gabrielle Lyon** (0:00)
Today, we're cutting through the confusion about women's hormones, fitness, and muscle growth. Dr. Lauren Colenso-Semple is a leading researcher in female physiology, and her work debunks a lot of popular myths.

**Dr. Lauren Colenso-Semple** (0:15)
Many scientists are hesitant to study women because of this unknown influence of the menstrual cycle or hormonal contraceptives on whatever outcome they're studying.

**Dr. Gabrielle Lyon** (0:28)
Do menstrual cycles really affect your gains? Should you train differently on the pill? And what about the viral trends like cycle sinking and fasted cardio? This is the science women need to hear. Dr. Lauren Colenso-Semple, welcome to the show.

**Dr. Lauren Colenso-Semple** (0:49)
Thank you so much for having me.

**Dr. Gabrielle Lyon** (0:50)
I am really excited to have this conversation. It is an important one, critical especially now because it seems as if women are getting much more interested in training, although, I don't know, you and I have been training probably our whole lives, and we can agree that muscle is the organ of longevity. Let me tell you why I wanted to have you on. You come from, and your colleagues will be deeply excited, the home of evidence-based information, and that is McMaster University. You have a PhD in Integrative Physiology. You also have a Master's in Exercise Science from the University of South Florida, and then a Bachelor's in Psychology and Nutrition.
Your research is unique, and it emphasizes female physiology and with a interest in muscle growth.

**Dr. Lauren Colenso-Semple** (1:52)
Yes.

**Dr. Gabrielle Lyon** (1:54)
You've also published and contributed quite a bit to the science, and there are many topics that we're going to cover in this episode. Topics that include oral birth control, cycle syncing, which seems to be very popular these days. The training differences between men and women, we're definitely going to cover fasted cardio, and that's just the beginning.

**Dr. Lauren Colenso-Semple** (2:17)
Yeah.

**Dr. Gabrielle Lyon** (2:19)
Before we start, I would love to just briefly hear about your background as to how you got interested in such a specific area of science.

**Dr. Lauren Colenso-Semple** (2:29)
I developed an interest in the resistance training literature and really muscle physiology in general when I was working as a fitness professional in New York City. I wanted to get the best results for myself and be the best coach possible for my clients at the time. When I decided to go back to school and get a master's degree and subsequently a PhD, I really wanted to help fill that gap because I think all scientists would agree that women are underrepresented in the literature.
And what I found out was many scientists are hesitant to study women because of this unknown influence of the menstrual cycle or hormonal contraceptives on whatever outcome they're studying. So my hope in really looking into some of this was twofold. One, we don't know much about the ovarian hormones. We know a ton about testosterone. So do they influence muscle? And two, if the cycle phase or hormonal birth control isn't going to influence the outcomes that we're measuring, this can open up so many doors for more scientists to start studying women.

**Dr. Gabrielle Lyon** (3:45)
It's fascinating that women, I was reading that women were not included or necessarily included into research until 1993

**Dr. Lauren Colenso-Semple** (3:54)
Yeah, I think a lot of the foundational studies that we have are certainly in men. I do think the more and more research we do in women, we often find there aren't actually sex differences. But that doesn't mean it's not important to do the work.

**Dr. Gabrielle Lyon** (4:11)
Were you surprised that there weren't as many sex differences as you thought? Did you go into research thinking, OK, well, I'm definitely going to respond differently than, say, my husband is? Did you have a preconceived notion of what the variations in training would be and how individuals respond to muscle, or their muscles respond to training?

**Dr. Lauren Colenso-Semple** (4:34)
Looking back, no, because just from a practical perspective of training myself and training men and women over the years, the principles were always the same. And then you just adjust for individual preference and what is sustainable for that person. But I think there wasn't anything really that I did as a coach or as a woman training that was unique just because I am a woman or because I was coaching one.

**Dr. Gabrielle Lyon** (5:06)
One of the really important aspects of having you on is on your Instagram actually do a wonderful job. A lot of scientists are not very active on Instagram, but you do definitely spend time going in to social media versus science. Probably some of my favorite posts of yours. And there is something out there. There was this idea that individuals should work out for each phase of their cycle.