If, like me, you find yourself shutting down after about 4 or 5 hours (I know....light-weight ), can I suggest 'Amino Load'?
I tried this on Tony Bear's recommendation( coz he sells it) on Monday afternoon and got myself round a circuit that included: The Nab, White Nancy, Kerridge trig, Teggs, Shutt, Cat n Fiddle, Derbyshire Bridge, Ax edge trig, shining tor, thirsbitch, Sponds Hill trig and back to Styperson.
It's nothing compared to the antics of Nancy B et al, but for me, that is a long way and apart from a few jelly babies, I got round just drinking 2x 500mls made up using the powder and some electrolyte mixed in and felt great(ish). So for me it might just be the way forward.