Okay. So who didn’t have chills after watching this run from all-star stunt woman Jessie Graff from American Ninja Warrior (aka the best television show ever made)? To put things in perspective, Jessie Graff was one of the only athletes (among BOTH males and females) in the entire episode to make it to the last obstacle. To top it all off, ninja athlete Drew Dreschel was the ONLY person to complete the entire course among 35 athletes total. So this course was brutal for BOTH men and women.
In fact, all the obstacle courses you see on American Ninja Warrior are a level playing ground for both males and females. There are no “female” courses and “male” courses.
But wait — that’s not fair! Women are weaker than men, right?
In fact, I’ve been asked about this topic several times in just this past week alone. The questions that particularly stood out to me were:
- Why do women have less upper body strength than men?
- Why can’t women burn fat as quickly as men?
- Why do women have to work so hard to gain muscle mass?
First, let’s take a look at the anthropometric differences between men and women.
Before puberty, boys and girls basically have similar physical features in weight, height, and body size. When puberty begins, however, hormonal changes in the body trigger differences in male and female physical development. Testosterone levels become higher among males, thus ramping up bone formation and protein synthesis in muscle. Women have significantly lower levels of testosterone than men. Women develop increased levels of estrogen which triggers bone growth for females, but also stimulates breast development and increases fat deposition. In addition, boys initiate puberty later than girls and also have a longer growth period (and thus have greater stature than adult women).
Now let’s look at men and women’s absolute (compared independently) and relative (compared proportionally) strength differences.
If you’re looking at absolute strength (independently compared – not proportional in size), then:
- Women generally have two-thirds the strength of men (women have less muscle than men overall)
- Absolute lower body strength of women is closer to men
- Absolute upper body strength of women is typically less than men
On a relative basis (man and woman have similar body weight, fat-free mass, and muscle cross-sectional area), however…
- Lower body strength of women is similar to men
- Upper body strength of women is somewhat less
If you look at strength in regards to the cross-sectional area of muscle alone, there is no significant difference in strength compared to women and men (implying that muscle quality in a man is no different than that of a woman’s).
In short, here are three important take-aways:
- Men overall have more testosterone than women (meaning more muscular protein synthesis in males)
- Women generally have less muscle mass (cross-sectional area of muscle); CSA is correlated with muscle strength
- Men and women with similar muscle CSA have no difference in strength
What does this all mean in English?! Basically, puberty gives males a running start at developing ginormous muscles and getting stronger. However, women who resistance train consistently can still increase their strength gains (relatively) at the same rate, or even faster, than men.
As demonstrated by my shero Jessie Graff in the video above, women are training harder, getting stronger, and pushing their limits everyday. Yes, we are at a biological hormonal disadvantage. Yes, men are physiologically more equipped. But with consistent training and perseverance, we can also have muscle gains and can give men a run for their money in competition!
Haff, G. G., & Triplett, N. T. (2015). Essentials of strength training and conditioning (4th ed.). Champaign, IL: Human Kinetics.
Testosterone. (2015, November). Retrieved August 09, 2017, from http://www.webmd.com/men/testosterone-15738#2
Tips, N. T. (n.d.). Trainer Tips: Hypertrophy. Retrieved August 09, 2017, from https://www.nsca.com/education/articles/trainer-tips/hypertrophy/