How fit should you be to do the Lake District 4 peak challenge?
You need to be tremendously fit. But more importantly you need to be prepared for the peculiarities of the weather in the Lake District. I think anyone can become fit enough for this challenge, but it is the mental strength required to outwit the weather at anytime of the year. Make sure you have a good team who can contact you with important changes in the weather. There are good sources of weather for the lake district including Weather Line and a semi-professional weather station owner at Mirefoot. Good luck.
