There are different schools of thought on this, so I’ll weigh in on this using physiology and my experience with training a great number of champions in various disciplines for both sexes.
The short answer is yes, women should train diffently than men, especially initially. As levels of strength rise, those differences tend to level off. After 2 years of training, there is no difference between males and females.
There are however, many key characteristics to take into account when writing a training program for a female. Here is a list of observations to optimize your strength training design for women:
1. More training frequency is important initially for females.
Most females need at least a frequency of 3 days a week per muscle group for optimal gains in the early stages. The Chinese have been very successful at training weightlifters at the international level both in males and females. Upon analyzing their training system, what stood out is that they use much more training frequency with the females than the males.
2. Because of the lower endogenous levels of androgens, volume per training unit should be smaller in terms of sets and number of exercises.
In most instances, the training volume per training unit should be about 20-35% lower. Most females get the major part of their hypertrophy in the first year of training. It then plateaus dramatically, even though strength still comes on mainly through neural adaptations.
3. It is harder for females to gain hypertrophy.
Not only because of lower androgen endogenous levels, but also because women only have 60% of the number of nuclei per muscle fiber than males.
This makes them less prone to muscular hypertrophy than males of the same age with equivalent training experience.
4. The stronger the female, the more her training should look like the one of her male counterpart.
Strength is the great equilizer, not only on the field but also between the sexes. The neural drive and muscle fiber make-up needed to develop strength tends to make a female react to training more like male would, hence the differences are much less the stronger a woman is.
5. Biomechanical issues and cultural issues should be considered.
For example, North American women athletes are often weaker in relative terms in the vastus medialis muscles, hamstrings, erector spinae, and scapulae retractors than athletes from other countries. In short, get to know the biological make-up of your client in their cultural context.
6. Pound for pound, females will have actually have stronger legs than males
(i.e. of course, if they properly trained.) This is important for sports where maximal and relative strength ratios play a large part, such has gymnastics. It will also affect the development of females in cross-training sports. Point in case: ever noticed the leg muscle development of elite Crossfit female competitors compared to their upper body? I know you did
7. Contrary to popular belief, the upper body lift that females can approximate the most to the performance of males is in the chin-up or the pull-up
(i.e. if they are properly trained.) In fact, I use this exercise to evaluate the quality of knowledge of a personal trainer/strength coach. A competent one will get a female to do 12 chin-ups in twelve weeks. That is of course assuming that the client is not clinically obese. In a regular-weight client, 12 weeks is the time it takes a female to 12 strict chin-ups.
8. Female clients are far easier to coach than male clients
As they don’t let their ego spoil the methodology and follow instructions far better than males. In 1994, I had seven woman clients who were World Champions in their respective sports. What they all had in common was the good sense to communicate to me on a regular basis, so that I could finely tune their training loads.
Interestingly, the worst individual to coach is the nineteen-year-old male, who usually goes through this phase of life as if he believes he is born with infinite knowledge.