Subjects with CKD will undergo exercise training on a stationary bicycle for 20-45 minutes, 3 times per week, for 6-12 weeks. Additionally, subjects will take 1300-2600 mg (2-4 pills) of sodium bicarbonate prior to each exercise session three times a week.

Subjects with CKD will undergo exercise training on a stationary bicycle,for 20-45 minutes, 3 times per week, for 6-12 weeks. Additionally, subjects will take 2-4 placebo tablets prior to each exercise session three times a week.

Subjects with CKD will undergo progressive whole body stretching and toning exercises 3 times a week for 20-45 minutes for 6-12 weeks. Additionally, subjects will take 1300-2600 mg (2-4 pills) of sodium bicarbonate prior to each stretching session three times a week.

Subjects with CKD will undergo progressive whole body stretching and toning exercises 3 times a week for 20-45 minutes for 6-12 weeks. Additionally, subjects will take 2-4 placebo tablets prior to each exercise session three times a week.

Sodium bicarbonate tablet is 650 mg for one tablet. Oral sodium bicarbonate will be given out as 1300mg-2600mg (2-4 pills) prior to each exercise or stretching session. Serum bicarbonate measurements will be monitored throughout the study (at 2 weeks, then every 2-4 weeks thereafter), and bicarbonate dosages will be adjusted to avoid metabolic alkalosis (serum bicarbonate > 30).

Near-infrared spectroscopy (NIRS) will measure and record tissue oxyhemoglobin, deoxyhemoglobin, and total hemoglobin.

Near-infrared spectroscopy (NIRS) will give an estimation of the pH levels within the muscle interstitial space. Muscle interstitial pH markedly decreases during exercise, and is often lower than blood pH with a larger intracellular to interstitial pH gradient. CKD patients may have less ability to buffer pH changes in the interstitial space during exercise. Bicarbonate supplementation may improve muscle interstitial buffering capacity during exercise, and prevent exaggerated reductions in muscle interstitial pH during exercise.

Dorsal hand vein model will be used to assess vascular alpha-1 adrenergic responsiveness by measuring the degree of venous constriction in response to varying dosages of local phenylephrine (PE) infusion.

Functional sympatholysis is determined by measuring the change in forearm oxygenation via near infrared spectroscopy (NIRS), and forearm blood flow and conductance using ultrasound, during sympathetic activation induced by lower body negative pressure (LBNP), at rest and during handgrip exercise. NIRS measures and records tissue oxyhemoglobin, deoxyhemoglobin, and total hemoglobin.