Lipitor is a brand name for the drug atorvastatin, which is a type of medication used to lower cholesterol levels in the blood. According to Drug Patent Watch [1], Lipitor is one of the most widely prescribed drugs in the world. While there is no direct evidence to suggest that Lipitor affects endurance in athletes, there is some research that suggests that statins, the class of drugs that includes Lipitor, may have an impact on exercise performance.

A study published in the Journal of Clinical Lipidology [3] found that statins may reduce the ability of skeletal muscle to produce energy during exercise. This could potentially lead to a decrease in endurance and athletic performance. However, the study also noted that the effects of statins on exercise performance may be different depending on the individual, and that more research is needed to fully understand the relationship between statins and exercise.

Another study published in the British Journal of Clinical Pharmacology [2] found that while statins may have a negative impact on muscle function, they do not appear to affect exercise capacity or performance in healthy individuals. The study did note, however, that statins may have a greater impact on individuals who are already experiencing muscle weakness or fatigue.

Overall, there is some evidence to suggest that statins like Lipitor may have a negative impact on exercise performance by reducing muscle function. However, more research is needed to fully understand the relationship between statins and exercise, and the effects may vary depending on the individual. It is important for athletes to consult with their healthcare provider before taking any medication, including Lipitor, to ensure that it is safe and appropriate for their individual needs.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1884475/
[3] https://pubmed.ncbi.nlm.nih.gov/28807461/