Lipitor is a medication used to lower cholesterol levels in the blood. It belongs to a class of drugs called statins, which work by inhibiting an enzyme that plays a key role in cholesterol synthesis [1]. While Lipitor has been shown to be effective in reducing the risk of heart disease, some studies have suggested that it may also have negative effects on exercise performance.

A study published in the Journal of Clinical Lipidology in 2017 found that treatment with atorvastatin (the active ingredient in Lipitor) was associated with a decrease in exercise performance in middle-aged men with dyslipidemia (abnormal cholesterol levels) [2]. The study found that atorvastatin treatment led to a decrease in maximal oxygen uptake (VO2max), which is a measure of the body's ability to use oxygen during exercise. The authors suggest that this decrease in VO2max may be due to a reduction in the production of nitric oxide, a molecule that plays a key role in blood vessel dilation and blood flow.

Another study published in the Journal of Clinical Endocrinology and Metabolism in 2013 found that treatment with atorvastatin was associated with a decrease in muscle mitochondrial function in healthy adults [3]. Mitochondria are the "powerhouses" of cells, responsible for producing energy. The authors suggest that this decrease in mitochondrial function may be due to a reduction in the production of coenzyme Q10, a molecule that is involved in energy production.

It is worth noting that not all studies have found a negative effect of statins on exercise performance. A review article published in the Journal of Clinical Lipidology in 2013 concluded that while some studies have suggested a negative effect of statins on exercise performance, the evidence is not conclusive [4]. The authors suggest that more research is needed to fully understand the relationship between statins and exercise performance.

In conclusion, some studies suggest that Lipitor (atorvastatin) may have negative effects on exercise performance, including a decrease in VO2max and muscle mitochondrial function. However, the evidence is not conclusive and more research is needed to fully understand the relationship between statins and exercise performance.

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/PMC3779874/
[4] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3835616/