"We tell them to be selfish: 'for the next few weeks it's your time'."
Those with part-time jobs need to consider cutting back, Mr Shepherd said. "I always encourage them to find somewhere in the house they can leave their study materials set up so they don't have to set them up again."
Students also need to be wise and avoid relying on late night cramming.
"Don't just plan to do it the night before because revision actually works."
The school has been holding special tutorials for students since the beginning of the term.
Nutritionist Rene Schliebs warns there's more to exam success than last-minute revision, chocolate bars and strong black coffee.
Students hoping to last the distance - the final NCEA exam is on December 4 - need to keep their eating habits in check.
"The thing to remember is the brain relies on carbohydrates for energy." Foods like rolled oats and Vogels were great for study, Mrs Schliebs said.
Students looking for a power-breakfast should begin their day with a bowl of porridge - a great source of vitamin B.
"B vitamins act like an anti-stress mechanism as well as providing energy for the brain."
And the best way to avoid an afternoon concentration lapse was to eat regularly, schedule in breaks and stay away from caffeinated products.
Snack foods such as almonds and sunflower seeds contained omega three fats which would help with staying alert, Mrs Schliebs said.
For a real boost, Mrs Schliebs recommends a serving of salmon, which contains high levels of omega three fatty acids.
And students should also resist reaching for an afternoon chocolate bar or coffee when the going gets tough.
"That's just a great big energy hit and great big energy drop."
Mrs Schliebs recommends taking a break and doing some exercise to help with re-focussing.
More than 143,000 students are sitting NCEA and New Zealand Scholarship exams.
NZQA deputy chief executive qualifications Richard Thornton said the biggest exam was Level One English. More than 46,000 students were due to sit the exam on Monday morning.
The smallest is New Zealand Scholarship Latin on November 20, with 19 students.APNZ
Staying focused* Eat regularly
* Stick to mixed grain foods like Vita Wheat crackers, Vogels and Burgen bread
* Snack on seeds and nuts
* Take regular breaks and exercise each day
Avoid:
* Staying up all night to study
* Junk food
* Fizzy drinks and other caffeinated products
* Other students who are stressed out
Wairarapa students sitting exams
Level 1: 783
Level 2: 673
Level 3: 416
New Zealand Scholarship: 85
Total student count sitting exams in Wairarapa: 1661
