one week of daily dosing with beetroot juice improves submaximal endurance and blood pressure in older patients with heart failure and preserved ejection fraction objectives this study sought to determine whether a relatively low single dose or a weeklong dosage of dietary inorganic nitrate could improve exercise tolerance in patients with heart failure with preserved ejection fraction hfpefbackground exercise intolerance is the primary manifestation of hfpef and is largely due to noncardiac factors that reduce oxygen delivery to active skeletal muscles a recent study showed improved exercise capacity in patients with hfpef after a single acute dose of beetroot juice brj 129 mmol inorganic nitrate while another recent study showed neutral and negative effects of an organic nitratemethods twenty hfpef patients 69 7 years of age were enrolled in an initial crossover design comparing a single acute dose of brj 61 mmol nitrate to a nitratedepleted placebo brj a second phase 1 week of daily doses used an alltreated design in which patients consumed brj for an average of 7 days the primary outcome of the study was submaximal aerobic endurance measured as cycling time to exhaustion at 75 of measured maximal power outputresults no adverse events were associated with the intervention submaximal aerobic endurance improved 24 after 1 week of daily brj dosing p 002 but was not affected by the single acute dose of the brj compared to placebo consumption of brj significantly reduced resting systolic blood pressure and increased plasma nitrate and nitrite in both of the dosing schemesconclusions one week of daily dosing with brj 61 mmol inorganic nitrate significantly improves submaximal aerobic endurance and blood pressure in elderly hfpef patients