There are a few of us doing 5x50 this year are team name is HU/C25K-2016
I'm opting for 30mins every day. It sounds a lot but it honestly isn't as I intend to use the 50 days to work specifically on my stretches and Stregnth. So I will workout 30 min gentle stretches or a little walk and it won't interfere with my running too much then add in some Stregnth work and by the end of the 50 days I'm hoping to of really built up my body to complement my running. I am the sort of person who need a little push with stretches and Stregnth.
It's only £5 to join and goes to a good charity.