. . . for lifting, training, or exercise - do less.
. . . for diet - eat more.
"Do less" for training encourages you to actually rest, to pare down to what is really needed, and otherwise keep things on track. Cut away anything that isn't measurably improving your progress.
"Eat more" for diet counters that tendency to drop to sub-1000 kcals for fat loss or to skip meals to lose weight, or to just not eat enough when trying to gain! If things get stuck, nudge the calories up a bit and see what happens. Only if your progress fails consider another option.