So how can we convince them otherwise? 

Greatness is achieved in the face of adversity.  Greatness requires sacrifice.  The child finds themselves engaged in a war.  They have to give up their own "life" slaving away through ever increasing difficult tasks.The child does this not because he/she likes to fight, but because the stress of studying has become greater than his or her resolve. So how to attend to these problems? Well first of all DO NOT confront your child if you can at all help it!  You're asking them to fight this war and you need their cooperation!  When your child finds that they can redefine the battle on their terms then you have given them control. 

While it's good for them to learn control, their learning should be productive. So instead of confronting them take a step back and reassess. Why are they being asked to sit for possibly multiple hours and do something that would be difficult for an adult to do?  Is this really the price they must pay for their parents love? 

In this case it is time to renegotiate with your ally and also to STRENGTHEN your bonds with them!  The more loyalty and love they feel for you the harder they will work.  If they can create a confrontation and subvert these feelings they can buy some minor relief and justify behavior which they know that you will not approve of.  Don't give them this chance. If they are struggling, sit with them and help them in a positive affirming way. If they are going to work hard, then they deserve rich rewards, and top tier support.  Bring them some snacks of some of their favorite foods after they've accomplished something of significance, and engage them in some family games to allow them to rest and recuperate and re-bond with you. You may have to also make some sacrifices to assure that your valued ally is on board with you for this tough war.  You may be tired from work, etc.  but greatness requires sacrifice.  Does your job really need you to be there for so many hours?  Maybe you can order food so you can spend more time with your children. When things aren't going right, it's time for a reassessment on all fronts. 

Also many parents I see just ask their children to study, and, that's it!  Childhood is about learning to be a full functioning adult, and that means responsibilities.  Your children should learn to cook, do laundry, calculate finances, and all the other things that adults are expected to do.  It's even better if they can be given these responsibilities to help the family.  It will reinforce the fact that they are contributors to the welfare of the family and that their contributions are valued and necessary.  

When you're in the store they should be mentally calculating all purchases and seeing if you are paying too much at the register. When a family member is sick ask them to use their knowledge of biology to theorize what may have happened and engage them in building a plan to help heal the sick family member. Make their education meaningful and relevant.  Once they are convinced of the value of their education, then the same energy that they devote towards resisting their studies may be re channeled into their studies and you may even want to hold them back for fear of over exertion!