Lipitor, also known as atorvastatin, is a medication used to lower cholesterol levels in the blood [1]. According to a study published in the Journal of Clinical Lipidology, statins, including Lipitor, have been shown to improve exercise capacity in patients with dyslipidemia, a condition characterized by abnormal levels of lipids in the blood [2].

However, another study published in the Journal of Clinical Endocrinology and Metabolism found that long-term use of statins, including Lipitor, may negatively impact skeletal muscle function, leading to decreased endurance during exercise [3].

Therefore, while Lipitor may improve exercise capacity in patients with dyslipidemia, long-term use may have negative effects on skeletal muscle function and endurance during exercise. It is important to consult with a healthcare provider before starting or stopping any medication, including Lipitor, and to discuss any concerns about its potential impact on exercise performance [2][3].

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/