claim: Eurotas (river) is one of the major rivers of Laconia.
evidence: Performance-enhancing substances , also known as performance-enhancing drugs -LRB- PED -RRB- , are substances that are used to improve any form of activity performance in humans .. A well-known example involves doping in sport , where banned physical performance -- enhancing drugs are used by athletes and bodybuilders .. doping in sport. doping in sport. bodybuilders. bodybuilding. Athletic performance-enhancing substances are sometimes referred to as ergogenic aids .. Cognitive performance-enhancing drugs , commonly called nootropics , are sometimes used by students to improve academic performance .. nootropics. nootropics. Performance-enhancing substances are also used by military personnel to enhance combat performance .. The use of performance-enhancing drugs spans the categories of legitimate use and substance abuse .. substance abuse. substance abuse