Add some speed to your workout. Typically I recommend this in the form of interval training, which is high fatigue. However, most exercise leaves you feeling energetically slow and stiff. The primary reason for this is that the fatigue level is high.
For an invigorating alternative, add a few workouts each week that are explosive and low fatigue. For example, try 5 squat jumps for height, rest 60 seconds and repeat for as many sets as you can before you notice a slight decrease in jump height. You can also try throwing a 5-40 pound sand bag or medicine ball for distance or doing 20 meter sprints.
These workouts will leave you feeling fresh, energetic and explosive. In addition they will compliment your other workouts well. Be creative and let me know if you need any ideas.