To recognize when it's time to change a workout routine, pay attention to plateaus in performance, diminished motivation, and increased fatigue. If exercises become less challenging or enjoyable, it may signal a need for change. Additionally, consider incorporating variety to target different muscle groups and prevent injury. Regular assessment of goals, progress, and fitness interests can also indicate when adjustments are necessary to keep the routine effective and engaging. Listening to your body’s feedback and feeling consistently refreshed after workouts can help determine the right time for a change.