Matthew Walker

“Full across 70 countries twice a year and it's cool daylight savings time. Now in the spring when we lose an hour of sleep. We see a subsequent 24% increase in…”

Walker claims a global daylight-saving-time study across 70 countries found a 24% increase in heart attacks when clocks spring forward and a 21% decrease when they fall back.

“5 medical residents will make a serious medical error due to insufficient sleep one in 20 medical residents will kill a patient because of fatigue-related era …”

Walker claims 1 in 5 medical residents will make a serious medical error and 1 in 20 will kill a patient due to fatigue-related error.

“There was a 70% reduction in car crashes the following year when they made that sentence 0% something to to be a revolution. Here's a simple biological factor …”

Walker claims that delaying a high school's start time produced a 70% reduction in teen car crashes the following year, citing the specific case (named earlier in the same passage) of Teton County, Wyoming shifting its school start time from 7:35 to 8:55 a.m.

“I'll give you two examples that there is a city where they just took individuals and they just gave him 4 hours of sleep for one night and what they saw it was…”

Walker claims that a single night of only 4 hours of sleep causes a 70% reduction in natural killer immune cells, and implies this is a reason insufficient sleep produces cancer.

“If you have elective surgery, you should ask your surgeon how much sleep they had in the past 24 hours if they had 6 hours of sleep will last you have a 170% i…”

Walker claims a surgeon who slept 6 hours has a 170% increased risk of causing a major surgical error like organ damage or hemorrhage, compared to a well-rested version of the same surgeon.