In 1985 I was working at a health club, and aerobics classes were very popular. Leg lifts were a staple of the classes. Leg lifts can be done laterally, kicking backward, or forward. They can be done standing, on all fours, while doing a plank, leaning on an exercise ball, or lying on your side. There are other ways as well. In the course of a class they are performed in high numbers.
I did the math. I figured 60 to 70 leg lifts were performed a minute. There were 8 to 10 minutes of leg lifts per class. If you went to several classes in a week and showed up 50 weeks a year you would be doing close to a quarter million leg lifts. One woman did. At the end of the year she still had substantial fat deposits on her outer thighs. In fact that was the only place she had noticeable fat on her body.
Around this same time I occasionally worked out a man who liked to drink beer, and he occasionally exercised. His body fat was about 30%, much of it around his abdomen and much less around his lower body. When he did the leg extension exercise you could clearly see the four muscles of each of his quadriceps, and he had very little fat on his hips.