Based on the information available, there is no specific evidence or studies indicating that endurance changes early in Lipitor (atorvastatin) use. Lipitor is a statin medication that is primarily used to lower cholesterol levels and reduce the risk of heart disease [1].

Statins, including Lipitor, have been extensively studied for their effects on cholesterol levels, cardiovascular health, and potential side effects [2]. While some studies have reported side effects related to muscle pain or weakness, there is no consistent evidence suggesting that endurance changes early in Lipitor use [3].

It is important to note that individual responses to medications can vary, and some people may experience side effects not commonly reported in clinical trials. If you have concerns about your medication or are experiencing unusual symptoms, it is always best to consult with a healthcare professional [4].

In summary, based on the available information, there is no evidence to suggest that endurance changes early in Lipitor use.

Sources:

1. Mayo Clinic. (2021). Atorvastatin (Oral Route). Retrieved from <https://www.mayoclinic.org/drugs-supplements/atorvastatin-oral-route/description/drg-20064551>.
2. National Library of Medicine. (2021). Atorvastatin. Retrieved from <https://medlineplus.gov/druginfo/meds/a601262.html>.
3. DrugPatentWatch.com. (2021). Lipitor (Atorvastatin Calcium). Retrieved from <https://www.drugpatentwatch.com/drugs/lipitor>.
4. U.S. Food and Drug Administration. (2021). High Cholesterol Medicines (Statins). Retrieved from <https://www.fda.gov/drugs/postmarket-drug-safety-information-patients-and-providers/high-cholesterol-medicines-statins>.