User:IcecreamPenguin/sandbox

An increase in muscle endurance is primarily attributed to the large amounts of caffeine in pre-workout supplements. The ingested caffeine acts as an adenosine receptor antagonist, which serves to reduce the overall pain experienced by the consumer, allowing them to workout for longer periods of time.

Pre-workout has shown to decrease the time it takes for muscles to recover from intense exercise, allowing athletes to reduce time between training sessions. The improvement in muscle recovery is associated with the branched chain amino acids (BCAAs) found in pre-workout, particularly, glutamine.