Sleep Patterns for Different Body Clocks During Two Versus Four Back-to-Back Work Shifts

Increasing night shifts from two to four resulted in greater sleep debt for early chronotypes and lower sleep debt for late chronotypes.

• Sleep debt varied based on chronotype, with early types accumulating more sleep loss over four consecutive night shifts.
• Late chronotypes experienced reduced sleep debt after four night shifts, indicating a different response to shift length.
• No significant interaction effects were observed between shift sequence length and chronotype for morning shifts.
• Social jetlag remained unchanged regardless of the number of consecutive night shifts.
• Including naps did not alter the relationship between shift length and sleep debt.

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