When you think about the qualities you’ll need to be a successful doctor, stamina is undoubtedly on the list. Though the hours vary by specialty, medicine is not a path you choose for work-life balance. In fact, the famously long shifts required of first-year residents, and their effects on patient safety as well as learning opportunities for residents, are a source of ongoing controversy.

In 2011, the Accreditation Council for Graduate Medical Education (ACGME) imposed a 16-hour limit on shifts for first-year residents. A select group was allowed to work 30-hour shifts as part of a study designed to determine the effects of long shifts on patient outcomes and in-service learning.

Recently, the ACGME increased the limit to 24-hour shifts.

One school of thought is that extra-long shifts provide invaluable learning opportunities for residents. Those who fall in this camp argue that caring for the same patients day and night provides a continuity that allows residents to be fully aware of all the variables relevant to a patient’s case and to take greater “ownership” of the patient. In addition, the night shift at a hospital tends to be a time when more specialists are on hand, providing more chances for residents to learn from their expertise.

Opponents of shifts that exceed 16 hours point to the dangerous effects of sleep deprivation on patient care and doctor safety. Can a doctor who hasn’t slept in a day or more be expected to provide the highest quality of care to patients? As for learning opportunities, how well can they focus on adding to their knowledge base when they’re struggling to stay awake?

These issues were hotly debated within the medical community when in 1984 an 18-year-old died during a visit to an emergency room where overworked residents with less than two years combined experience treated her. The case forced the debate into the spotlight and drove the call for shift limits.

Some physicians actually believe shift limits have done more harm than good. While supporters of reduced working hours blame sleep deprivation for putting patients, doctors, and the public at risk, physicians who oppose shorter shifts argue that handoffs (changing doctors two to three times daily) are more responsible for mistakes. They also point out that if shifts are split in half, residents risk missing the first 24-hours of a patient’s admission, which is crucial training experience.

One proposed solution may satisfy those in favor of shorter hours: have patients alternate their evening shifts in a pattern that would allow them to spend adequate time with specialists, but also follow patients through the complete cycle of treatment.