When I was studying for my masters degree in nutrition and functional medicine, I was introduced to Dr. Stacy Sims’ years of research in sports nutrition, and her mantra “Women are not small men” really hit home. As a girl growing up with three brothers in the piney woods of southeast Texas, I did a fine job of keeping up with the boys in sports and all manner of physical activity that tested strength or speed. However, all of that changed once puberty hit. While the boys developed pecs and abs, I developed hips and breasts, and my days of beating them, or at least holding my own, in competitions became less certain. Suddenly, the notion that a girl can do anything a boy can wasn’t a sure thing, because now we’re hormonally and physiologically different. The boys were experiencing testosterone, BO and body hair, while I was on a very complex hormonal journey that generated a lot of eye rolls coming and going. So, I knew just what Dr. Sims meant, and the implications were far reaching.
In the world of research (medical, nutritional, sports & fitness), women tend to be underrepresented. In 1994, the US National Institutes of Health (NIH) issued guidelines for design and analysis in clinical trials to ensure the safety and efficacy of drugs in both genders. Yet, in 2005, 8 of 10 prescriptions drugs withdrawn from the US market were because of negative health effects in women.1
Clearly, those 1994 guidelines weren’t being followed, so in 2006, the NIH implemented a new policy requiring researchers to consider gender a biological variable. An analysis of papers published in 34 biomedical journals during 2019 showed a significant increase in studies that included both sexes, BUT there was no change in the proportion of studies that analyzed the data by gender.2 The old adage “What’s good for the goose is good for the gander” does not apply when it comes to biological research.
A few reasons why analyzing gender differences in the research matters:
- Women account for more than 75% of all autoimmune diseases
- Women are two times more likely to be diagnosed with chronic fatigue syndrome
- Women are three times more likely to suffer from chronic migraines
- About two-thirds of patients with Alzheimer’s disease are women
- Women make up 90% of the cases of fibromyalgia
- Women experience depression at twice the rate of men
Shrink it and pink it
The reason women tend to be excluded from studies is because we have complex hormonal fluctuations during our reproductive years that create confounding variables in the data. Men, on the other hand, are simple. Their hormones are relatively steady and don’t fluctuate like ours. They have one job — make sperm. Prior to puberty and after menopause, female hormones are also in a steady state, so the generalizations of the data are less outlandish, but still not accurate. The highest quality research includes both genders and accounts for the hormonal variances in women versus men. There’s quite a bit of pushback in the world of research to do that, because it adds a measure of complexity and cost that most investigators don’t want to tackle or lack the resources to do so.
Take a look at popular topics like ketogenic diets, intermittent fasting, paleo, and high intensity interval training (HIIT). Much of the original research was done on sedentary obese males who needed to lose weight prior to surgery, then extrapolated to the fitness population. The notion that research done on males can be generalized to females, especially in sports and nutrition, has been referred to as the old ‘shrink it and pink it’. Just make it look pretty and put sparkles on it, and that’ll do. However, doing that ends up forcing female athletes to train and fuel just like males, and that can be detrimental to both performance and ongoing health.
Why the “orange effect” may have women seeing red
A popular boutique exercise chain promotes 30-minute high intensity interval training (HIIT) as an efficient way to burn calories and lose fat. The “orange effect” philosophy is based on maximizing post-exercise oxygen consumption thus raising metabolism. While visiting one of their locations for the first time, I was told that their specialized HIIT workouts would keep my metabolism up and increase my calorie burn for up to 21 hours afterward. Oh, but that’s only true for guess who — men.
While women burn more fat during exercise than men, the opposite is true for recovery, where women burn more carbohydrates and men will burn an increased proportion of fat. And, here’s where the “orange effect” and the mostly single gender (male) research behind it goes awry. A woman’s metabolism drops back to normal within 3 hours, while men’s will indeed remain elevated up to 21 hours. I’m not saying HIIT training is terrible for women, but it’s not as great as we’re led to believe, and there are factors to consider when making it part of a workout regimen in order to maximize results and recovery without putting undue stress on the body.
I’ll save “How to optimize your workouts based on your menstrual cycle” for another article, but here’s a little teaser that may surprise you. A woman’s exercise physiology is most like a man’s during her period and the few days after. It’s best to save strength training workouts for the first half of the menstrual cycle (first day of your period until ovulation) when the body can produce more force and make greater strength gains. During this time, a female’s body is also less likely to feel pain and can recover faster.
Women have more rhythm than men
We all experience the well known 24-hour circadian rhythm that regulates our body processes – digestion, hormone production and regulation, body temperature, metabolism, sleep and elimination. This cycle resides within both genders, and when our modern lifestyle creates a dysregulation with our body’s clock, it can lead to a host of health issues like diabetes, cancer, gut dysbiosis, ulcers, depression, obesity, loss of cognitive function, ADD/ADHD.
But there’s another time-based pattern that only women experience and it’s the 28-day infradian rhythm of their menstrual cycle. Infradian means a cycle longer than one day, and this particular clock is divided into four phases – menstrual, follicular, ovulatory, luteal, and hormones fluctuate to accommodate each phase accordingly. A woman’s circadian and infradian rhythms are inextricably linked to her overall health and wellbeing, and they continue to be glossed over in clinical trials and research, so it’s up to you to understand how to make your infradian cycle work to your benefit.
Why a woman can’t win at ninja warrior
The popular television show ‘American Ninja Warrior’ is a competition where non-professional athletes vie as individuals to complete an obstacle course in the shortest amount of time. Let’s go back to Dr. Sims’ mantra “Women are not small men”, and take a look at basic physics. A male’s center of gravity is located in the middle of his chest, which provides him with much more power and strength in his shoulders and upper body. A female’s center of gravity is right in the middle of her pelvis, which puts her strength and power in her lower body. That’s why, for most women, it’s much more of a struggle to do military style push-ups and pull-ups. Our fulcrum to our lever is in the wrong place to do them as efficiently as men.
The obstacles on ‘American Ninja Warrior’ are mostly designed to demonstrate upper body strength. There’s a lot of dangling from bars, and swinging like a monkey, and generally pulling yourself up to propel yourself forward. The various courses are designed to showcase upper body strength, making it much more likely men can complete it, while very few women push the winner’s button at the end.
Some amazing women have managed to power through those obstacle courses to victory, but the men will always be more likely to win, and do it in a shorter amount of time, as long as the lion’s share of the obstacles continue to be created to showcase upper body strength.
It’s time for women to understand how to work in sync with their physiology and fluctuating hormones to maximize everything from fitness, to digestion, to mental health and cognitive function.
Are you interested in learning more about how your female physiology can become your superpower? Reach out to Merritt Wellness and set up a time to speak with me or one of our other functional medicine practitioners.
- Gender bias in research: How does it affect evidence based medicine? https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1761670/
- A 10-year follow-up study of sex inclusion in the biological sciences https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7282816/