Why Women Are More Resistant To Training Fatigue Than Men.
Less isn’t always more when it comes to women and strength.
Men have been said to be physically stronger than women in every way—but are they really? Strength can be proven and tested in many ways so using blanket statements such as “men are stronger than women” is really hard to justify.
Yes, men produce more testosterone than women, but this doesn’t make them superior physical beings or able to achieve intense feats of strength and fitness above any female.
Yes, hormones play a big role in each sex’s ability to handle different types of workloads and intensities. However, factors such as metabolic differences, fat storage, muscle fibre types, and bone mass all impact the way one can perform certain physical tasks and how quickly one can recover.
Men can typically handle shorter bursts of intense effort (sprint work or heavy signles at a 90%+ intensity) while women can endure longer efforts at a submaximal intensity (distance work or multiple repetitions at a 70-85% intensity)
The first major contributor to these differences is our metabolism
Males and females both go about this process very differently from one another. As briefly mentioned above, women can perform tasks of strength over a longer and more consistent period of time. This is due to the rate of glucose uptake in their muscles during training which makes them more metabolically equipped than men to endure this style of training. Generally speaking, men have a 50 to 100% higher rate of elevated fasting blood glucose. However, they also have a 30 to 50% slower rate of glucose uptake than women which can slow down their intra-training recovery (1).
Glucose is our number one fuel source for muscle contraction. Without it, we can’t continuously produce the same level of consistent effort and output. With the help of ATP and the mitochondria, glucose is turned into usable energy for your muscles to perform the task at hand. If this turnover rate is slower, your recovery will be impacted.
Now, knowing that women generally have lower fasting blood glucose levels than men (not always the case), it could mean they won’t immediately have the available required energy for a heavy single as would most men. However, since women have a quicker rate of glucose uptake during training or physically demanding tasks, they’re able to perform endurance-style lifting schemes better than the majority of men.
Another contributing factor to these strength differences is the hormone of Estrogen.
You read it right—estrogen is largely responsible for women’s general ability to handle more volume in strength training than men. This hormone is a key player in the process of glucose uptake (as we explored above) which goes hand in hand with achieving faster muscular recovery (2).
Let’s set this up in an example. A female lifter goes to perform 3 sets of 3 reps at 85% of her 1RM deadlift. Throughout her rest between each set, the process of glucose uptake kicks in to provide her with more fuel for her muscles to use on her next set. Here’s where estrogen comes into play.
After your muscles receive a strong stimulus, such as performing a lifting set during your training, your metabolism gets the green light to start recruiting more energy via ATP and mitochondria through the process of glucose uptake. Every single human possesses estrogen receptors in their mitochondria. So, it makes sense that women can create the necessary energy to perform their next task quicker than men. The higher the demand for fuel (or glucose), the more the mitochondria will rely on estrogen to help produce readily available energy for muscular contraction.
So, thanks to the abundance of estrogen women tend to have, it enables their mitochondria to rapidly intake this hormone and have them feeling ready to go for their next set.
Next up, men and women differ in muscle fibre types and their dominance.
Even when comparing men and women on an even scale (trained vs untrained individuals), women generally have 2/3 of the muscle mass men do. While their overall muscular density might differ, they have a great proportion of Type 1 muscle fibre types—around a 1:4 ratio of Type 1 fibre to total fibre area on any given muscle (3).
Type 1 muscle fibres contain more mitochondria and they tend to be recruited during more “endurance” type activities. This inherently increases your ability to get more blood flow to your muscles and it can oxidize glucose for high-volume workouts. Women’s power output might be lower overall than men’s but they are far more resistant to fatigue during strength training.
So, what can we make of this?
We’ve established women have the ability to withstand longer bouts of strength-related efforts because they can access the required energy for intra-workout recovery faster than men. Plain and simple.
They’re equipped with more estrogen, more type 1 muscle fibres, and faster energy recruitment via glucose uptake.
A male lifter has a higher potential of being able to perform a true 1RM while a female lifter may hit a 3RM but might only be able to perform a single at 5 to 10 kilos more than her 3RM result.
It’s worth noting that the considerations made above do not determine a male or female lifter’s potential for maximal strength or feats strength endurance. Every individual will have a threshold for the amount of workload they can handle. Male and female differences aside, every single lifter, athlete, and gym-goer has to apply themselves and put in the work to see the results they want.
Citations & Studies
Faerch K, Borch-Johnsen K, Vaag A, Jørgensen T, Witte DR. Sex differences in glucose levels: a consequence of physiology or methodological convenience? The Inter99 study. Diabetologia. 2010 May;53(5):858-65. doi: 10.1007/s00125-010-1673-4. Epub 2010 Feb 25. PMID: 20182862.
Liao TL, Tzeng CR, Yu CL, Wang YP, Kao SH. Estrogen receptor-β in mitochondria: implications for mitochondrial bioenergetics and tumorigenesis. Ann N Y Acad Sci. 2015 Sep;1350:52-60. doi: 10.1111/nyas.12872. Epub 2015 Aug 24. PMID: 26301952.
Staron RS, Hagerman FC, Hikida RS, et al. Fiber Type Composition of the Vastus Lateralis Muscle of Young Men and Women. Journal of Histochemistry & Cytochemistry. 2000;48(5):623-629.