I reckon you should do whats already suggested, but you might want to keep a schedule or time-table. Not something too hard ie. 200 miles ftw!!! but some thing more like, jog 20 minutes and sprint 10 everyday (if your goal is to become fit for example).
If its studying, then do what I do: 45 minutes one subject, 15 mins free time, 45 minutes another subject or a part of the same subject that you didn't see earlier, 15 mins break, 45 mins of what you did in the first place.
It won't seem like much (if you're concentrated) when you do the first 45 and you'll be like oooh now I get 15 minutes break. In the end you'll have done over 2 hours worth of studying without loosing your sanity.
Hope that helps.
If its studying, then do what I do: 45 minutes one subject, 15 mins free time, 45 minutes another subject or a part of the same subject that you didn't see earlier, 15 mins break, 45 mins of what you did in the first place.
It won't seem like much (if you're concentrated) when you do the first 45 and you'll be like oooh now I get 15 minutes break. In the end you'll have done over 2 hours worth of studying without loosing your sanity.
Hope that helps.