Lack of sleep can double the time it takes to get abs.

A single night of poor sleep negatively affects muscle recovery.

If Luke and Nicole lose muscle on their plan, it will take them longer to get abs because more of the weight lost will not be fat.

Multiple long-term studies have found that consistently poor sleep dramatically slows muscle growth and fat loss.

In a study, a sleep-deprived group (5.5 hours of sleep) lost 75% of their weight from lean mass, with fat loss cut in half, compared to an 8-hour sleep group where half the weight lost was fat.