After seven to eight weeks of more sleep, the players ran faster in short training races.

VOA: special.2010.06.09

Stanford sleep researcher Cheri Mah says sleep should be part of an athlete's training program.

VOA: special.2010.06.09

So while the infants' internal physiological distress levels had not changed, their outward displays of that stress were extinguished by sleep training.

CNN: Should babies be allowed to 'cry it out'?

Half the babies were placed in a sleep-training group and the other half in a control group that did not use sleep training.

CNN: Should babies be allowed to 'cry it out'?

Observing 25 infants aged 4 to 10 months in a five-day inpatient sleep training program, researchers monitored levels of the stress hormone cortisol in the babies, who were left to cry themselves to sleep without being soothed.

CNN: Should babies be allowed to 'cry it out'?