Observing the Ekadashi fast
Means controlling our ten sense organs (indriyas) plus the eleventh, the MIND.... Not only controlling them, but also diverting them to Lord Swaminarayan instead of material pleasures. The rewards of observing this fast even involuntarily are infinite. On this day one should ideally refrain from taking any food or water, nut for those who are incapable can drink water. Those who can't even do that, can drink milk once. Obviously there are those who can't even do that, so they can eat fruits.

One should avoid sleeping during the day, says Lord Swaminarayan in the Shikshapatri. This is because while sleeping one may have impure thoughts which could nullify the fast. Also, during ekadashi one should observe 'Jaagran', which means to stay up till midnight, singing or reading Lord Swaminarayan's glory.