I went out for a ride with my gf yesterday. It was only 24.5 mi. with approx. 1300 ft. of climbing. The climbing is basically in the middle of the ride so it does slow you down. We finished at 14.4 mph but more importantly my legs ached and I felt tired the entire ride. My gf, who is a gym rat and nutrition focused, thinks I have changed my diet too drastically. Her theory is that I've cut back on carbs severely enough that it's actually hurting me. This reminds me of a conversation I had recently with a rep from Hammer Nutrition. I wasn't seeking advice other than how to get started with their products. But, he maintained that if I cut back drastically on calories my body could go into starvation mode and try to conserve fat. I'm beginning to think this may be affecting me.