5 Hour Grading effects

hi... folks



im doing a 5 hr grading at the weekend ... due to my work patterns .. i start work four times before that this week at around 3.30am .. then getting 2 hrs or less sleep during the day before teaching some evening classes ...



Not counting the fact ill be knackered which I generally am anyway ... after about 3.5 hours last time ... the cramps set in ...



im thinking bananas and oralyte rehydration drink .. and possibly some of those new sport like rehydration tabs they have in asda in the yellow tube ... ive seen a few articles but again no one person is the same ...



Any ideas on energy boosts for the critically knackered and cramps .. especially when the self defence element involves a lot of changing levels from ground to standing up ... etc ...cramps occured in the joints and tendons around the knee and calf area .....



thanks