If by some chance, they did not, they were punished. No one was except from some form of work and if the impossible targets were not met fines would be issued, people would sent off to labour camps or simply shot. .
As an incentive to work harder, workers were encouraged to compete against each other; hard work was often rewarded with high praise or slightly better pay. To be a Stakhanovite was a great honor, you were so named if you worked extraordinarily well as Stakhanov had done himself. In some factories workers were paid by results. Most workers were motivated by the fear of the horrific, inhumane conditions at the labour camps. Whatever the project may be, building dams or statues, the task was to be completed in set amount of time, at any cost, even human life. A normal working day was 8-10 hours, with 4-5 hour shifts. To ensure that inevitable absenteeism didn't occur, labour books reflected how hard a worker had worked day to day and their frequency of attendance. Peasants working on the collectivized farms were denied the right to leave the collectives which forced them to apply themselves more heavily to their work. When people started to strike or express disapproval of the speed at which they should progress, Stalin said "It is sometimes asked if it is not possible to slow down the tempo somewhat to put a check on the movement. No, comrades, it is not possible! On the contrary, we must increase it as much as it within our power and possibilities to do so." By using words like "comrades" and providing the people with a cause, Stalin suppressed any disapproval and encouraged praise and admiration. And, of course, punished anybody who spoke out against him, who did not extol his praises, with death or inevitable death in the gulags*. But without the successes of the five year plans, where would Russia have been? There was only evidence that the standard of living would have gotten worse for Russians, they may have been destroyed by a war they were not equipped to fight in and this is why so many people saw Stalin's plans as genius rather than monstrosities; hard work and death as a necessary sacrifice for advancement.