If your health is lacking due to stress, poor sleep or diet to the extent that it inhibits performance, you risk losing the entrepreneurial race.

Make no doubt about it: Entrepreneurship is as much an endurance race as it is a sprint. Winning takes what we in the SEAL Teams call “tactical patience” to know when to throttle forward and go “all out,” or when to cease-fire and step back.

Fitness is a large part of who I am and what I also believe to be a leading contributor to personal success. To optimize your fitness and business performance, there is one element that can be developed to help fill the holes wielded from hardship -- your core.

Related: Going the Distance: How Improving Your Health Helps Improve Your Bottom Line

Core, according to the genius known as my Mac’s dictionary, is “the central or most important part of something ... that is central to its existence or character.” In other words, the core is the foundation that serves as the support structure for the outer shell that guides you and facilitates performance -- both in the workplace and the gym.

For instance, the human body’s “core” acts as a support center as it protects the inner organs, helps stabilize and transfer muscle movement and maintains strong posture. Similarly, a business’s “core” connotes a central nucleus of values, ideas and guiding behaviors from which leadership decisions emerge that (ideally) support the best interest of the company.

Much like an athlete who depends on his or her core as a pillar of performance, what a leader carries around at his or her “center” is what people either remember or reject. A leader’s core is the source of his or her greatness -- or lack thereof.

If a leader’s core value is service, then selfishness gets him nowhere. Likewise, if gratitude is at a leader’s core, then “thank you” is part of his daily vocabulary because that’s what he stands for as he knows it will create value.

Related: The Two Simple Things Everyone Needs for a Healthy Body

Below are three integral components to building a strong core, both in the gym and in business:

1. Trust is central to everything we do and everyone we meet. While exercising, for example, we trust that our muscles will stay strong and not give way under stress, or that physical therapy worked and we can now return to the scene of the crime (i.e. the gym). In business, we trust that others are competent enough to carry out a task and that their intent is positive. Bernie Madoff, for example, may have been a competent stockbroker, but his intent -- not so much. An airline pilot must be trusted with the skills to fly safely and the intent to not dive-bomb the plane into the ground. In all instances, trust is a core element of progress.

2. Flexibility. The value of physical flexibility is widely known as it allows you to move from one challenge to another (such as touching your toes without back pain). Mental flexibility, however, is what facilitates learning and allows you to form new mental models. In the business world, indicators of organizational flexibility include:

  • First-level employees understand the strategy and direction of the company, and can therefore make their own decisions.
  • No duplicative efforts because employees would rather over-communicate than under-deliver.
  • A willingness to adapt to market fluctuations without creating chaos in the company or sending employees into deep depression.

3. Shared purpose. In terms of physiology, a strong core is mutually supportive: the quadriceps complement the hamstrings, abs support the back as the back supports the abdominals. There’s a shared purpose amongst muscle groups, which is to facilitate performance. Similarly, the challenge of leadership is to foster the same mutually supporting structure where employees share the same purpose and operate with the same conviction and effort as their organizational counterparts.

What lies at the center of a leader’s core is fundamental to performance, as a leader’s core serves as the guiding light when challenges arise. If you want to build your leadership, try strengthening your core.

Related: What Separates a Great Leader From a Good One?