Use 'ease off' to indicate intentionally reducing the intensity or effort in an activity. He decided to ease off on his exercise routine after the injury.
Pro Tip 2/3
Gradual Process
The phrase implies a gradual or smooth transition, not an abrupt stop. You should ease off the studying tonight; your brain needs rest.
Pro Tip 3/3
Controlled Adjustment
Suggests a controlled or deliberate reduction by the person in charge. The pilot was instructed to ease off on the plane's speed as it approached for landing.