01/31/2013 11:29 am ET | Updated Apr 02, 2013

I Work Harder For Male Spin Teachers: Discovering An Unconscious Gender Bias

I am a ritual exerciser: I exercise at the same time of day, after eating the same exact breakfast, while wearing the same sports bra. A few months ago, I started taking spin classes at a new studio near my daughter's school, which lets me reserve the exact same bike day after day. At last, I had complete consistency every single day. It was love at first ride.

This state of the art studio also allows me to track my performance each class. I can log on to my account and see information about every pedal stroke since I first started taking classes. Under my name there is a grid that shows me the date of the class, who the teacher was, which bike I used (always #20), how many miles I logged and how many calories I burned.

I rarely check those numbers, but I was curious about whether my performance was improving over the past few months, so I logged on and reviewed my stats.

At first, I was proud to see that my mileage was steadily climbing and that I was working with greater intensity. It felt good to see that confirmed by the numbers.

Then, I noticed something that troubled me. I noticed that both my total mileage and "total power" exerted during class were noticeably higher every time I had a male teacher. At first, I thought it was just because I favored Mitchell's '80s mash-ups (think Katy Perry meets Whitney Houston). But when I studied the numbers, I could see that it wasn't just in Mitchell's class that I pushed harder. I also got higher scores in David and Richard's classes. Conversely, when Cindy or Lara or Jess were at the helm, my "total power" scores were at least 15 points lower, and my mileage was about 5% lower.

Obviously, this is not a scientific study, but it still disturbed me that I seemed to be working harder for the male teachers. Everything else was the same, except for the gender of the instructor. Why wasn't I working as hard for the female teachers? I wanted an explanation besides subconscious gender bias.

But what other explanation is there?

All of the teachers, male and female, show up for class pumped about the 45 minutes we will spend together. They all inspire me. For each of the classes, there are some songs I hate and some I love so much I sing along. I am not conscious of being more intimidated by the male instructors or feeling like I have to impress them or keep up with them. The female instructors are all buff enough to crush me like the Goldfish snacks my kids drop in the car, so they are plenty intimidating and inspiring, and I show up for each class wanting to have a good ride where I sweat out some toxins and burn off some energy.

I can't explain why my numbers look like they do. I consider myself well-educated and self-aware, and I wrote a Master's thesis on issues in Women's Studies. I kept my maiden name and use the F-word (feminist) to describe myself. I assumed I was one of the last people who would unconsciously work harder for a male than a female.

The day after I was studying my spin class stats, Secretary of Defense Leon Panetta announced that women in the military would no longer be prohibited from direct ground combat. When I heard the news, I cheered for the thousands of jobs that would now theoretically be open to female soldiers. Eventually, women will rise through the ranks and become the leaders in our modern-day trenches. And that will be a good outcome for everyone, right?

But, what if my spin class results are an outgrowth of plain old gender bias? Does that mean that if I was following a male leader into combat, would I charge a hill faster or invade a village more stealthily? If my leader was female, would I put ever so slightly less gusto or exertion into the mission? While it would never be conscious, would it happen nonetheless? And what about (male) soldiers who, unlike me, consciously object to having female soldiers on the ground, much less having them serve as the leaders of ground missions?

If my diminished performance in the female teachers' class is related to their gender, what can I do about it? How can I reverse the complex set of circumstances that compel me to push harder for a man, especially when I am not aware that gender is playing any role in my willingness or ability to exert myself? How will our armed forces be able to confront and combat gender bias in the increasingly complex situations they will no doubt face?