The blog authored by Alex Hutchinson, a famed and respected columnist for many magazines, winning national awards. He has also recently published a book: Endure; the mind, body, and curiously elastic limits of human performance! Definitely worth a read! Having reviewed it myself, i can definitely recommend it!
Runner’s world focuses on nutrition and endurance running, offering resources to develop runners in any way possible, from food to shoes, and brains to the training field.
Find it here; Runner’s world