# The shorter your sleep, the shorter your life
Sleep is also crucial for physical health on nearly every aspect.

> Routinely sleeping less than six or seven hours a night demolishes your immune system, more than doubling your risk of cancer.

Just this should be enough of a reason to get enough sleep.

## A vivid example: Daylight Savings
There is an experiment on what happens when you cut an hour of sleep which happens yearly and involves 1.5 billion people around the globe: Daylight Savings.

After an hour of less sleep there is a 24% spike in heart attacks the next day. It also works the other way: After an hour of more sleep there is a 21% reduction of heart attack rates.

This same trend is also evident with traffic accidents and even with suicide rates.