Using the right carbohydrates at the right time helps give you a steady energy flow. Breakfast is important to give you energy after being asleep for several hours, try porridge, fruit with yoghurt or wholegrain toast.
Healthy snacks between meals will keep blood sugar levels even, try dried or fresh fruit, nuts & seeds.
Simply keeping yourself hydrated will improve physical and mental performance making you feel energised, try drinking water regularly throughout the
day increasing the amount if you exercise.
Make sure you have the right food available, make your own to take to work if you have to, plan ahead.
Some people also benefit from taking vitamin & mineral supplements.
After all that working out you need to allow time for your body to recover. If you are really training to the maximum or trying to gain muscle mass you will probably need to supplement your diet with additional protein.
Using good quality food is adequate, we have got by using this for a while, but protein shakes do help to supply your body with the extra hit it needs if used correctly.