When I first started TTC I weighed about 116 pounds (I am 5'6") and every night was doing about 50 HARD minutes on my treadmill, walking fast at incline intervals, and drinking tons of ice water. I was also lifting the heaviest weights I could several times a week. I was a traditional chinese medicine fertility nightmare. While I was still having cycles, they had shortened from 28 day clockwork cycles to 23-24 days with less bleeding and less bright red blood. I still ovulated every month but I was hardly at peak fertility.
My acu convinced me to quit this and just walk easily and do yoga. She also convinced me that I had to gain some weight. I did so and within a few months I was back to 27-28 days and 4 days of bright red blood. There was definitely a difference.
I think this kind of brutal exercise is just not good for optimal fertility and conception. Moderate exercise is good; extreme exercise is not.