Hi Luke
Just to pick up from what Graeme mentioned re: footware.
Early last year I purchased a pair of running shoes from Amazon after reading rave reviews about them, I thought they would be a good buy, how wrong could I be! I started getting numb feet then soon after a knee injury which needed physio treatment (he suggested the change in footware might have been the cause).
Anyway I went to Sweatshop in Castleford, who can analyse your running style (they film you whilst on a treadmill). It turned out that I am a neutral runner so do not require any support in my shoes and I also require a wide fitting, the Amazon shoes (Brookes) had support and were too narrow. Since purchasing my new shoes (New Balance) , I have not had any further problems (touch wood).
So you do need to be careful when purchasing running shoes, what’s good for one runner is not necessary good for you.
Tony