A long workday can be both mentally and physically draining. As a result, office workers and professionals whose jobs are more physically demanding than office work may find themselves less alert at the end of the workday than at the beginning.

A loss of alertness as the workday draws to a close might be unavoidable. But professionals whose sense of alertness begins to dwindle in the thick of the workday might need to take steps to improve their alertness to protect themselves from injury and to ensure the quality of their work does not suffer.

• Avoid caffeine in the late afternoon. Some professionals rely on caffeinated beverages such as coffee or energy drinks to combat afternoon drowsiness. While that afternoon caffeine fix might provide an immediate, if temporary, jolt of energy, it might also affect a person’s energy levels the following day. A 2013 study published in the Journal of Clinical Sleep Medicine found that caffeine consumed as early as six hours before bedtime can significantly disrupt sleep. Professionals who reach for a cup of coffee in the late afternoon might get a sudden boost of energy, but their energy levels the following day might be lower due to a poor night’s sleep.

• Avoid high-fat foods at lunchtime. Foods that are high in fat should always be avoided thanks to their connection to a host of health problems. Such foods also negatively affect energy levels when consumed in the middle of the day. The University of Rochester Medical Center notes that the body digests and absorbs high-fat foods very slowly. That means workers who eat high-fat foods for lunch won’t get the afternoon energy boost that low-fat, healthy lunches will provide.

• Snack healthy. Professionals who find themselves needing a snack in the mid- to late-afternoon can sate their hunger and give themselves an energy boost by snacking healthy. Avoid snacks like potato chips that tend to be high in fat and low in nutrition. Foods that are high in fiber and/or protein can provide a longer energy boost and quell the afternoon hunger pangs at the same time. Fresh fruit and Greek yogurt fit the bill.

• Change your workout schedule. Regular exercise improves short- and long-term health while also increasing daily energy levels. Professionals who include exercise in their daily routines yet still suffer from a lack of alertness in the afternoon may need to alter their workout schedules. A 2011 study published in the Journal of Occupational and Environmental Medicine found that participants who were assigned afternoon exercise programs during work hours reported increased productivity versus those who were not assigned afternoon workouts. If working out in the afternoon is not feasible, avoid working out too late at night, as the National Institutes of Health note that exercising within two to three hours of bedtime can disrupt sleep, ultimately having a negative impact on energy levels the following day.

Professionals who find their alertness levels waning in the afternoons can combat such drowsiness in various ways.