A good night’s sleep is an important component of muscle recovery. Not getting enough sleep can also dull your focus. But what effect does sleep deprivation have on strength? A study published in The Journal of Sports Medicine and Physical Fitness takes a look using young Karate athletes as volunteers.
 

On separate occasions, subjects took selective attention and muscle strength tests after a normal night’s sleep and a night of no sleep. Testing took place around 9 AM, Noon and 5 PM the following day. The time it took to apply maximum force increased and activation time decreased during middle of the day and evening tests after a night with no sleep.