I'm currently attempting to build up my run miles for next years Angel Fire endurance trail run. It'll be a challenging 31 mile run over mountains and through valleys using national forest trails starting at the base of the Angel Fire ski resort. Currently my endurance is poor, I have a long way to go. Last week my longest run was 6 miles. I ran it slowly and it was uncomfortable.
Earlier this week I started a low carb diet I read about in "The art and science of low carbohydrate performance". It's a low carb diet for endurance athletes. When I started this diet I assumed my endurance and speed would decrease. I was also fully expecting to feel horrible. So far I feel great. Today I ran a little over 7 miles consuming nothing but water and felt fantastic. Feeling even better than I had felt on a traditional endurance athletes diet was not what I was expecting, but that is exactly what has happened.
On my first day of my low carb diet I lost 2 1/4 pounds. I'm back into the 220's again! So far I'm loving this.