I take a spin class 1-2 times a week, and wear MTB shoes with spd clips - as do most of the riders. There are usually 12-15 people in the class (early morning) and usually only 2-3 males including me. The gym recently upgraded to new bikes and a system that displays everyone's rpms, power and energy (calories burned) on a large tv screen at the front of the room. This leads to some friendly competition, and lately a few of the women have been taking the top 2 positions