This study examined the validity and reliability of the sport- specific endurance plank test, which was designed in an attempt to advance the core test originally developed by Mackenzie (2005) as a surrogate measure of global core muscle endurance in athletes. The current sEMG data validated the claims that the performance of prone bridge (plank) during the new test recruits trunk flexors as well as the lumbar extensors; the plank manoeuvre interspersed with the alternate lift up of arms and legs imposes extra loading upon these muscles. Construct validity of the new test was also suggested by its ability to discriminate the changes in the global core muscle endurance subsequent to a pre-fatigue core workout. For test-retest reliability, the test was also shown to be reliable (CV), especially if the first of the three trials were used as a familiariza- tion trial (CV).