For women who already lift weights, slowly increasing how many sets they do every couple of weeks doesn’t help them build thicker thigh muscles any more than just keeping their workout the same over...

For women who already train regularly, doing more resistance training each week does not lead to a measurable increase in the thickness of the outer thigh muscles after 12 weeks, even though other aspects of fitness may improve.

For women who already train with weights, doing more sets per week—up to 38—does not lead to noticeably bigger thigh muscles after 12 weeks compared to doing 22 sets per week.

If you lift weights twice a week for 8 weeks and do the same total amount of work, your upper and middle thighs will get thicker — no matter what fancy technique you use.

Over 12 weeks, adding more sets to weekly resistance training sessions leads to larger gains in leg strength and muscle size in the vastus lateralis of trained women, but does not significantly change the overall thickness of the lateral thigh muscles.

In women with about two years of weight training experience, gradually increasing the number of sets per week over 12 weeks leads to bigger gains in leg strength and muscle thickness in the front thigh muscle, but not in the overall thickness of the side thigh muscles, compared to doing the same number of sets every week.