What are behavioral interventions for laziness in children?

Structure. It is not necessarily that kids are "lazy". It may be as simple as a schedule and expectations problem. Some kids are in so many activities they are burned out and have little time for anything else. Most kids nowadays live to be on a wireless device and that takes a chunk of time. Have clear expectations of your child and let him know what they are. Unplug the tv, limit the phone gaming time.
For non-compliance, . make sure he understands what behavior you want, the immediate reward for compliance & the immediate consequence for non-compliance. Negative or positive attention reinforces a behavior. Ignore a behavior & it will stop after it first escalates in an attempt to elicit your old response. Learn effective discipline techniques for his age from a parenting class or a behavioral therapist. .
CHECK POINTS. If sleep 8 hours a day eat and seat in the table 3 times a day has free time with friends and enrolled in 1 sport or hobby per week then this child has a normal daily routine.