Found this a while back its a great way of tracking the relative efficiency of your runs and organising them to become more progressive.
the number crunching link is available free at the bottom of the page.
myprotein also have an endurance recovery bundle at the minute
at £29.99 enter my discount code to get 10% off. Don’t think there are many left in stock.
• Recovery Evo provides 23g of protein per serving which will contribute to a growth and maintenance in muscle mass.
• Vitamin C contributes to normal functioning of the nervous system, normal psychological function, to the protection of cells from oxidative stress, and to the reduction of tiredness and fatigue
• Recovery Evo provides a carbohydrate and electrolyte blend which contribute to the maintenance of endurance performance during prolonged endurance exercise and enhance the absorption of water during physical exercise.
My code MARKPOTTERSITE10
They also have some good fueling tips for free.
Or more advanced version