There’s an old cynical expression: hard work sometimes pays off later, laziness always pays off now.
Using rewards you can change the situation so that ‘hard word always pays off now‘. This gives your self discipline a fighting chance against the seductive lure of the sofa.
It might seem overly simplistic or even offensive to suggest that you can change your behaviour with a treat, in the same way that you would train a dog. However, whilst scratching behind your ears or rubbing your belly is unlikely to get you to study, the truth is that we’re all motivated by rewards even though they can vary wildly for different people.
For rewards to be effective they need to be based on effort, not results, so that they are guaranteed. They also need to be small enough to occur frequently – hard work needs to pay off the same day, not next week.
Treats should be low cost such as watching an episode of your favourite TV show, eating a doughnut (not too many, mind), playing for half an hour on a video game, or getting a back rub from a willing volunteer.