Most personal trainers will tell you when they encourage their clients to lift more weight or move a little faster, most often those clients can and do. Although holding back is common, good trainers inspire people to give more and, in doing so, discover their potential.

Good trainers also recognize when clients can’t do more without risking injury. Perhaps they haven’t had enough sleep, they’re sick or experiencing chronic stress or pain. In those cases, it’s important trainers provide resources and referrals to help clients deal with underlying issues rather than press for more output.

Understanding and accommodating these different situations is essential in a business setting, too. When employees are well, leaders can tap into their potential by clearly defining their unique roles in the organization, ensuring they feel valued, giving them the tools to do their jobs well, fostering positive relationships and helping them grow. These strategies create a culture in which people willingly give their best efforts.

If every employee showed up to work each day healthy and well, we’d have the complete recipe for success. Because of episodic or chronic illnesses, though, people often show up, but don’t function at full capacity. They can’t give more even if they want to. In fact, showing up, but not performing has become so detrimental to the economy researchers have a name for it: presenteeism.

Studies show presenteeism costs businesses up to three times more than absenteeism. Because people are physically present, presenteeism often goes undetected. Such conditions as addictions, allergies, arthritis, asthma, back pain, gastrointestinal disorders and migraines aren’t always obvious. Because of their prevalence and frequent lack of treatment, they account for much of the lost productivity. One study showed depression in the United States costs employers $35 billion per year in reduced performance. Another study showed pain from such conditions as arthritis, back strain and headaches costs businesses $46 billion annually.

Think about the last time you experienced a headache, back pain, upset stomach or bout of depression. You might have gone to work, but probably moved more slowly, avoided high-demand tasks, expressed irritation and perhaps made mistakes.

Now, using Centers for Disease Control estimates that half of the adults in the United States suffer from at least one chronic condition, imagine the effects to your organization if half your employees underperform because of health issues. You can quickly glean the damage these conditions inflict on productivity and your bottom line.

Understanding these effects is the first step to addressing them. The next step is identifying specific health issues your employees face. One strategy is to assess the demographics of your employees and make an educated guess about which conditions are likely prevalent. For example, if you employ a high percentage of women, your work force might struggle with higher rates of irritable bowel syndrome since women suffer from hat condition twice as often as men.

Another strategy is to contract with a wellness vendor to conduct a health risk appraisal in which individuals voluntarily answer questions or submit to biometric screenings to produce an aggregate report on the prevailing health risks in your organization.

Education logically follows as a means to help employees prevent or better manage illness. Hold seminars about common health issues, provide access to screening tools and encourage employees to designate a primary care physician. While these interventions might seem costly, the direct costs of proper health care represent less than 30 percent of the total cost of an illness to an organization. Far higher costs leak from your organization as lost productivity when illness goes unmanaged.

Finally, it’s essential to remove the barriers employees face to managing their health. Provide paid time off and cultivate a culture that encourages people to take time off to help them recover more quickly and reduce the risk of spreading illness or perpetuating low-performance norms and burnout. Provide such benefits as free flu vaccines, employee assistance programs and wellness programs. These efforts produce savings that far outweigh initial investments.

If you believe most employees want to do their best, inspire them to dig deep when they’re well. But also support them with education and resources when they’re not. This training approach likely could become your single best competitive advantage.