I tried to run a lot and stay very low carb (under 50). The marathon I ran at the end of March was a very poor showing for me. I have also had a lot of terrible training runs and my runs have actually slowed down. I attribute all this to diet, as I should be running faster, particularly with the added weight loss. My 5K time at the end of April was also slow. I have seen improvement over the last little while with the added carbs.