This has been extracted from Pharmacy Daily http://www.pharmacynews.com.au/News/Latest-news/7-things-to-know-about-coffee-and-sleep
A major review of caffeine’s effects on cognitive, physical and occupational performance concludes it is a good remedy for offsetting physical and cognitive degradation associated with sleep loss.
Caffeine improves alertness, vigilance, attention and reaction time, but less consistent effects were observed on memory and higher-order executive function, such as judgment and decision making.
Caffeine, in doses exceeding 200mg, also has positive effects on physical performance including improvements in endurance, muscle strength and high intensity sprints typical of team sports.
The researchers conclude that people in many occupations, including the military, first responders and shift workers, would benefit from policies that encourage regular caffeine intake.
“In these circumstances, that may include restricted sleep, repeated administration of caffeine is an effective strategy to maintain physical and cognitive capabilities,” they write in the journalNeuroscience & Biobehavioral Reviews.
Overall, the researchers conclude:
- In doses up to approximately 300 mg, caffeine enhances a wide array of basic cognitive functions with minimal side effects;
- The effects of caffeine on higher-order executive skills, complex judgments, emotional discernment, and decision-making are unclear and need further study;
- The ability of caffeine to enhance cognitive and physical function is dose-dependent. Doses of approximately 40 to 300 mg can improve cognitive function in rested individuals, whereas doses of 200 to 500 mg ingested approximately one hour before exercise can enhance physical performance. Response to a given dose varies considerably from person to person;
- Caffeine has performance enhancing or ergogenic effects across a wide range of exercises, including endurance tests, time-trials, tests of muscle strength and endurance and high-intensity sprints;
- Threshold circulating plasma concentrations required to produce an ergogenic response may be as high as 15–20 ?M when caffeine is ingested before exercise but may be as low as 5 ?M when ingested during exercise. These threshold concentrations are lower for caffeine naïve individuals and the ergogenic response is present for several hours after ingestion;
- It is okay to use caffeine as an ergogenic aid in hot environments; and
- Caffeine is an effective strategy to counter both physical and cognitive degradation associated with sleep loss.
You can read the abstract here.