Talkback: Five ways to stop your legs cramping out of transition
Moving the cleat as far back as possible also helps with calf cramp as it removes the strain from the lower leg. Speedplay have extender plates which positions the cleat around 20mm further back.
And the evidence that dehydration or sodium loss causes exercise induced cramp is what? Thought so because there isn't any worth it's salt. More likely to be caused by the contract and relax muscle nerve signals getting out of sync. This has been observed in fatigued muscles
So stick to conditioning and race like training which will delay that fatigue.