Capacity of a physical system to perform work is called as energy.
Modern science says that human organism is compromised of two bodies, external body and internal body which are made up of bone, flesh, organs and tendons. The human energy system is very complex instrument continually struggling to "stay in tune" and maintain the balance with its inner self.
Get three hours of aerobic training a week - divide that into 30 minutes a day cut into three ten minutes segments. People who have as little as three hours of aerobic training a week have better memory, and are good at switching between mental tasks.
Work regular physical movement in your day to day work - if most of your work is conducted at desk level in front of a computer. Practice movement renewal strategy such as desk stretch or breathing exercise. Take frequent breaks walk around outside.
Eat metabolic - boosting food.Too much of sugar can increase your appetite then surpassing it rather eat high energy food like banana, meat, nuts and broccoli. Try egg white in the morning then cereals and protein shake in the afternoon. Spicy food and green tea have also both have proven effect on metabolism.