The researchers claim this is due the different pelvis shapes across genders that mean different structures are contacting the saddle. Women often have wider ischiopubic rami which means on a narrower saddle the body is supported on the pubic symphysis and the posterior sections of the ischiopubic rami. Men have a narrower more rounded ischiopubic rami which can be more easily supported by the narrower front section of the saddle.
Retrived from: https://opentextbc.ca/anatomyandphysiology/chapter/8-3-the-pelvic-girdle-and-pelvis/
When looking at the female specific saddle they found there was a significant pressure reduction towards the front of saddle. This is because the increased width may provide more support for the specific pelvic anatomy of women, providing them with a more stable base and even pressure distribution.
One limitation to consider with this study is that there was limited time (5 minutes) for riders to warm up and get used to each saddle. This means that the data might not be an accurate representation of how everyone truly interact with the saddle. They also admit that while they tried to match each riders bike fit, some of the studies parameters could have restricted their ability to do this.
The study concluded that more research was needed to understand how saddle properties change how pressure is distributed and how the saddle feels. It is worth noting though that as they found an improvement with the women specific saddle that when fitting women with saddle issues either a wider or a women’s specific saddle may be advisable.
POTTER, J. J., SAUER, J. L., WEISSHAAR, C. L., THELEN, D. G., & PLOEG, H. (2008). Gender differences in bicycle saddle pressure distribution during seated cycling. Medicine & Science in Sports & Exercise, 40(6)