Lipitor is a brand name for the drug atorvastatin, which is commonly used to lower cholesterol levels in the body. While there is no direct evidence that Lipitor can affect workout performance, there are some potential side effects of the drug that could impact physical activity.

According to Drug Patent Watch [1], some of the common side effects of Lipitor include muscle pain, weakness, and inflammation. These side effects could potentially impact a person's ability to exercise and perform at their best. In rare cases, Lipitor can also cause rhabdomyolysis, a condition in which muscle tissue breaks down and releases proteins into the bloodstream, potentially leading to kidney damage. While this is a rare side effect, it could certainly impact a person's ability to exercise.

However, a study published in the Journal of Clinical Lipidology [2] found that while statins like Lipitor can cause muscle damage in some patients, this does not necessarily translate to a decrease in physical performance. The study authors note that "the effects of statins on muscle performance are complex and multifactorial," and that more research is needed to fully understand the relationship between statins and exercise performance.

Another study published in the Journal of the American Heart Association [3] found that high-dose atorvastatin treatment did not have a significant impact on exercise capacity in patients with heart disease. The study authors note that "the use of high-dose atorvastatin did not result in significant changes in exercise capacity, which suggests that the drug does not have a negative effect on physical performance."

Overall, while there is some evidence to suggest that Lipitor and other statins could potentially impact exercise performance, the research is not conclusive. It is important for individuals taking Lipitor to monitor their own physical activity and speak with their healthcare provider if they experience any unusual muscle pain or weakness.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://pubmed.ncbi.nlm.nih.gov/28807461/
[3] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4679305/