Wake at a consistent time, including weekends
The least regular fifth of sleepers had body clocks about 2.5 hours later than the most regular fifth—effectively living with persistent jet lag. More regular students also had better grades.
What it takes
Free. Giving up weekend lie-ins takes some discipline.
What you may gain
Sixty-one university students kept records for 30 days. In the least regular fifth, melatonin onset was at 00:08 versus 21:32 in the most regular fifth, a circadian delay of about 2.5 hours. Peak sleepiness was about 1.8 hours later. Sleep regularity correlated with academic performance at r=0.37.
Context & considerations
One small study, without randomized comparison. Modeling suggested differences in daily light exposure explained most of the circadian difference. Pair a consistent wake time with morning daylight. After an occasional short night, go to bed earlier the next evening, rather than sleeping until noon.
Research & references
Phillips et al. (2017). Irregular sleep/wake patterns are associated with poorer academic performance and delayed circadian and sleep/wake timing. Scientific Reports. https://doi.org/10.1038/s41598-017-03171-4