When University of Michigan football coach Jim Harbaugh recently said he believes that the No. 1 natural steroid is sleep, he voiced what sleep disorder physicians have known for years.
The link between sleep and athletic performance is not anecdotal. Studies show that sleep deprivation can decrease athletic performance, and extending sleep can improve athletic performance.
Sleep and timing
The same system that times sleep and wake (the circadian rhythm) also times peak performance, which can have ramifications for competition times and travel across time zones for competition.
- In NFL games after 8 p.m. on the east coast, west coast teams are twice as likely to beat the point spread than east coast teams. This may be due to the fact that during late games, west coast teams (whose body clocks are still set on Pacific Standard Time) are playing closer to the peak time of physical performance.
- After long-haul travel (6+ time zones) military personnel and elite athletes demonstrate reduced sprint speed, jump velocity, jump height and strength for up to 4-6 days. This is likely due to jet lag, where there is misalignment between the local time and the internal body clock, which disrupts sleep and physical performance.