1.Compare the impact on submaximal exercise endurance of Empa, with and without KNO3, as compared to active control (Potassium Chloride, KCl).2.Assess the impact of Empa, with and without KNO3, on SkM OxPhos using novel in vivo MRI-based imaging techniques that quantify SkM OxPhos and intramuscular perfusion with exercise3.Assess the impact of Empa, with and without KNO3, on SkM respiration, the metabolome, and the proteome. The primary endpoint will be the change in submaximal exercise endurance(time to fatigue at 75% of peak workload)between the interventional therapies and active control (KCl). Skeletal Muscle MRI: 1.Change in SkM OxPhos following plantar flexion on MRI, 2.Change in intramuscular perfusion following plantar flexion on MRI Metabolic Efficiency:
3.Changein the kinetics of O2-consumptionwith submaximal exercise, 4.Change in VO2efficiency with submaximal exercise, 5.Change in the respiratory exchange ratio and venous concentration of substrates at standardized times during submaximal exercise, 6.Change in tissue measures of substrate metabolism, muscle proteome, and the muscle metabolome. Hemodynamic:
7.Change in the exercise vasodilatory reserve with submaximal exercise Quality of Life:
8.Change in KCCQ overall summary score, 9.Change in steps per day.

You may be eligible for this study if you meet the following criteria:

• Conditions: Medical Research
• Age: - 99 Years
• Gender: All