Just got in from a session, was doing speed endurance and i was wearing my Nike Superfly R2’s (very stiff plate) and i got cramp in the session despite being well fuelled and hydrated, wasnt too cold either and the rest wasnt long so it wouldnt have been off waiting around. I dont feel the spikes are suitable to be worn for a long time or for over 150 metres (especially with 6 or more reps). Got cuts and blisters under me toes and feet etc.
Last year i did lots of speed endurace, even things like one minute runs in my Adidas Heatstar Sprints, which have a much less stiff plate – and i had no problems – no blisters, no cramp etc
It then seems sensible to just wear them for speed endurace training, howeever i am wary off wearing two differnet pairs of spikes incase it effects my running style; also they are a compltely different make …