Reports that 'women have more stamina' look a little weak
"Women have more stamina than men," is the definitive sounding, yet entirely unsupported headline in The Times.
The study the headline is based on involved just nine women and eight men. Researchers asked each participant to do an exercise similar to calf raises (where the calves are used to lift a weighted bar or similar) 200 times.
It found that although men were more powerful and faster to begin with, they also became exhausted more quickly.
But the study was carried out in a lab and performance might differ to real life physical activity. It also didn't look at cardiovascular fitness and only investigated one muscle in the body – other muscles might perform differently.
For many people in England, it's not stamina that's the problem – it's actually taking part in exercise in the first place.
Read more advice about fitness and exercise.
Where did the story come from?
The study was carried out by researchers from the University of Oregon in the US and the University of Guelph and University of British Columbia in Canada. The study did not report funding sources.
The study was published in the peer-reviewed journal Applied Physiology, Nutrition, and Metabolism.
While the body of The Times and the Mail Online's reporting was accurate, both used misleading headlines. As discussed, The Times' headline was far too definitive for such a small study, while the Mail's claim that "the greater staying power of females means they can beat men in gruelling ultra-marathons – extreme running and cycling events that can last days" is entirely unfounded.
What kind of research was this?
This was a laboratory based study comparing a small number of men and women doing repetitive exercises similar to calf raises and looking at the effect of repetition on fatigue.
This type of research is good at looking at the mechanics behind why there might be differences in things like muscle fatigue between men and women. However, it cannot prove that women are better than men at endurance events as this depends on a range of things, including overall fitness. Ability also depends on training levels and preferred type of exercise.
What did the research involve?
Researchers took nine women and eight men from a local university in the US, all of whom were fairly physically active. They aimed to see if women were less likely to tire following a calf raise exercise repeated many times, and to examine if certain muscle-related factors were responsible for the fatigue.
Male and female participants were matched for age and physical activity levels and were asked to complete a calf raise-type exercise. They did 3-4 calf raises at maximum voluntary contraction (MVC), a measure of muscle strength. This provided the baseline MVC for each participant.
They were then asked to perform 200 of these calf raise exercises at 30% of MVC and were encouraged to carry them out as quickly and forcefully as possibly for all contractions.
They measured muscle performance by looking at:
- peak power – calculated using the maximum force applied and the speed the exercise was completed
- rate of force development (a measure of explosive strength) – calculated using the change in force applied divided by the change in time
- rate of speed development – calculated using the change in speed divided by the change in time
What were the basic results?
Women had a lower MVC (lower muscle strength), slower speed and less peak power than men. They were also lighter and shorter than men.
But immediately after the fatigue task (200 reps) had ended:
- women had a 15% less fatigue-related change in peak power (force and speed of exercise compared with men) – in other words, they tired less
- the change in force applied at peak power was 11% less for women compared with men
- women showed less change in power and speed at peak power over time compared with men
How did the researchers interpret the results?
The authors conclude that their study "indicates that females are less fatigable than males when performing fast unconstrained velocity shortening plantar flexions and this sex-related difference is, at least partially, a result of time-dependent mechanical factors within the muscle that contribute to rapid power production."
This study in a small number of students in the US indicates that when repeating the same calf-raising movement, women showed less fatigue in terms of force applied and time taken to complete the exercise.
Some UK media outlets directly link this to women being better than men at lengthy aerobic exercise activities such as ultra-marathons and long distance cycling.
However a number of factors might mean this is not necessarily the case:
- This was undertaken in a laboratory using seated exercise and participants might perform differently when undertaking physical activity normally.
- Only one muscle was investigated – other muscles in the body might perform differently.
- The study used a very small number of participants and the results cannot necessarily be generalised to the whole population.
- The participants were an average age of 21-22, so while this might be relevant for younger adults, it might not apply to older adult populations.
- While women showed less of a change (i.e. tired less) in things such as power and speed, they had lower scores on these parameters to start with – they were slower, less powerful and weaker. So the link with marathons and activities might not necessarily be true.
- There are a range of other factors that might affect fatigue in these situations – such as sleep, caffeine intake, blood sugar levels, and previous physical activity.
- We do not know if women retain this advantage of reduced fatigue over longer periods of time carrying out more reps. It's possible men level out the fatigue over time.
The best way to increase your stamina is to gradually increase the amount of exercise you do each day. Read more about getting started with exercise.
Links To The Headlines
Women have more stamina than men. The Times, August 25 2017
Women DO have more stamina than men and will soon be beating them in marathons. Mail Online, August 24 2017
Links To Science
Lanning AC, Power GA, Christie A, Dalton BH. Influence of sex on performance fatigability of the plantar flexors following repeated maximal dynamic shortening contractions. Applied Physiology, Nutrition and Metabolism. Published online June 21 2017