Stay Energized

Ironically, the answer is the opposite to what you would expect: To have more energy - in any form - put out more energy! Your entire being is designed to run as efficiently as possible, and to use only those resources that it needs to do the job at hand.

Physical Energy
If you lead a sedentary, quiet life, you will find your energy drops to a level that is only sufficient to manage this lifestyle. Conversely, if you engage in regular physical exercise, you will find your energy levels rising to meet the demand, and persisting in anticipation of future demands. So the secret here is: To have more energy available, put out more energy!



But don't think that you just "put your head down and work". That is often a destructive process as you "wear yourself out" by working but not investing time in ensuring that you are well fed, well rested and to a degree, well exercised.

"Hard work" is not "Exercise". This is a common misconception among businesspeople, and is one worth addressing here. 

Constructive and positive exercise for a human has exactly the same basis and principles as constructive and positive exercise for a race-horse: Short, spaced periods of controlled intensive activity, followed by rest periods, palliative care (massage, hot-tub, stretching) and first-class nutrition.

Mental Energy
One of the principles of physical exercise is that of "rotation" or "muscle confusion" in which the personal trainer or sports coach will include as a component in their training regime, exercises that are different to the run of the mill, and which change all of the time. 



Their purpose here is to ensure that the athlete's muscles cannot become "too comfortable in a familiar groove" but are being challenged to do new things all of the time.

This same principle applies to mental training. All of us tend to think and operate in our "familiar grooves" and the more specialized our work, the deeper the groove, often as not. 



One of the tricks in increasing our mental energy is in ensuring that we are continually challenging our mind with sources of new thinking. This is not to say that we dissipate our mental energies across an unorganized mass of topics; it is to say that occasionally - but regularly - we should spend a little mental effort on a field of knowledge with which we are not familiar.