Final answer:
Research has not conclusively proven that ginseng or ciwujia are effective ergogenic aids, and similar herbal remedies lack concrete evidence of efficacy.
Step-by-step explanation:
The question is asking whether ginseng and related substances, known as adaptogens, are effective ergogenic aids that enhance athletic performance. However, well-controlled research has not definitively proven that ginseng or ciwujia are effective in improving performance. While Chinese herbalists have utilized a variety of plants for health benefits for millennia, as indicated in Figure 14.2, the effects of these herbal remedies, including ginkgo, which is believed to improve brain function, still lack conclusive evidence. The mention of the placebo effect in the study by McClung and Collins (2007) suggests psychological factors can influence athletic performance perceptions, even without the actual efficacy of the substance in question.