Try using the "Yogic Coffee" breathing exercise to increase your energy. It only takes around 2 minutes but can be of real benefit to you. See
When you are feeling sluggish, try turning up the volume on the music. Just a few minutes of dancing can raise your oxygen level and heart rate, while increasing your energy level.
Surrounding yourself with items that are red, orange or yellow, will benefit you when you are feeling tired or low on energy.
Take an imaginary 10 minute vacation. Closing your eyes, breathing deeply and imagining your vacation spot in detail can refresh and energize you.
If you are feeling lethargic, try taking a brisk walk. Even just 10 minutes can be of benefit to your oxygen and energy levels.
Your brain doesn't have an energy reserve, so it needs a steady supply of nutrients. A few nuts or a piece of fruit can help raise energy levels.
Drink more water to stay hydrated, because water helps to carry energizing nutrients and oxygen throughout your body.
Sometimes, when you need to regain your energy, closing your eyes and relaxing for just a few minutes can work wonders.
Take a moment to be aware of your surroundings and focus on what is in front of you. This will help you to forget about feeling tired.
Try reading, listening or watching something that is funny to laugh it off. Laughing out loud can help to provide you the energy that you need.