Methods We will measure the rate of PCr resynthesis (the time constant of PCr recovery) following a controlled exercise protocol that will recruit muscles in the lower leg. We will evaluate muscle symptoms using a standardized questionnaire and measure muscle strength using an ergometer that was designed to apply a controlled variable pressure to a foot pedal through a pneumatic cylinder. We will perform baseline measurements after participants have been taken off statin medications and CoQ10 supplements (if applicable) for at least 2 weeks. Additionally, those with statin myalgia will have improvement of symptoms before baseline measures are taken. Following baseline testing, statin therapy+ubiquinol or statin therapy+placebo will be given to participants for 4 weeks. Repeat measurements will be performed at 4 weeks to compare the effects of statins+placebo versus statin+ubiquinol on PCr resynthesis. The primary outcome of this study will be the PCr recovery time constant. The post-exercise PCr recovery measurements will be performed in our MRI research facility using our dedicated 3T research MR scanner. Assessment of safety outcomes (CK, AST, ALT), and physiological parameters (BP, HR, height and weight measured), and blood measures of lipids and biomarkers (CRP, IL-6, TNF- α, E-selectin, VCAM-1, ICAM-1) will be collected on site and analyzed at the Harvard Catalyst Clinical Research Center (CRC) Core laboratory. Analysis of reduced and oxidized plasma CoQ10 will be performed at a qualified outside lab with a strong track record of using validated methods.