Final answer:
Tests are available to detect the use of synthetic EPO, which is considered cheating in sports due to its performance-enhancing effects.
Step-by-step explanation:
Erythropoietin (EPO) is a hormone produced by the kidneys that regulates red blood cell production in response to low oxygen levels. Injecting synthetic EPO is considered cheating in sports because it enhances performance by increasing red blood cell counts and improving oxygen delivery to tissues. As for detecting whether EPO has been used, the answer is Yes, there are tests available to detect synthetic EPO in athletes.