NAD+ and Exercise in FA

Inclusion Criteria:

1. Molecular diagnosis of Friedrich's Ataxia (FA).

2. Males and Females, Age 10 to 40 years (inclusive).

3. Girls, 11 years of age and older, must have a negative urine/serum pregnancy testand must use an acceptable method of contraception, including abstinence, a barriermethod (diaphragm or condom), Depo-Provera, or an oral contraceptive, for theduration of the study.

4. Not currently meeting exercise guidelines as outlined by The Physical ActivityGuidelines for Americans.

• Children and Adolescents should do 60 minutes (1 hour) or more ofmoderate-to-vigorous physical activity daily.

• As a part of their physical activity, children and adolescents should includemuscle-strengthening physical activity on at least 3 days a week.

• Adults should do at least 150 minutes (2 hours and 30 minutes) to 300 minutes (5 hours) a week of moderate-intensity, or 75 minutes (1 hour and 15 minutes)to 150 minutes (2 hours and 30 minutes) a week of vigorous-intensity aerobicphysical activity.

• Adults should also do muscle-strengthening activities of moderate or greaterintensity that involve all major muscle groups on 2 or more days a week.

5. Cardiac echocardiogram or cardiac MRI, performed within 1 year of enrollment,showing an LVEF > 45%

6. ECG, performed within 1 year of enrollment, without clinically significantarrhythmia.

7. Weight > 24 kg

8. Parental/guardian permission (informed consent) and if appropriate, child assent.

Exclusion Criteria:

1. Known sensitivity to NR.

2. Concurrent use of any medications, including statins, likely to increase risk of NRtoxicity.

3. HgbA1c > 8.5% and/or Diabetes Mellitus (DM) requiring insulin or insulinsecretagogue.

4. Use of supraphysiologic steroids.

5. Laboratory abnormalities that indicate clinically significant anemia or bleedingrisk. (Hemoglobin < 10 g/dL or Platelets < 100K)

6. Laboratory abnormalities that indicate clinically significant kidney disease usingserum creatinine and Modification of Diet in Renal Disease (MDRD) equation. (Estimated Glomerular Filtration Rate (eGFR) < 60 ml/min/1.73 m2)

7. Laboratory abnormalities that indicate clinically significant liver disease. (Aspartate Aminotransferase (AST)/Serum Glutamic Oxaloacetic Transaminase (SGOT) 3.0x Upper Limit of Normal and/or Alanine Aminotransferase (ALT)/Serum Glutamic PyruvicTransaminase (SGPT) 3.0 x Upper Limit of Normal)

8. Uncontrolled and persistent arrhythmias that are felt to be clinically significant.

9. Known history of moderate or severe left ventricular systolic dysfunction (LeftVentricular Ejection Fraction (LVEF) < 45%)

10. Standard contraindications to exercise testing.

11. Inability to sit and pedal unassisted in a cycle ergometry chair, at a cadence of atleast 55 rotations per minute (rpm) during unloaded warm up, in a cycle ergometrychair and complete a maximal Cardio Pulmonary Exercise Test (CPET)

12. Inability to sit and pedal unassisted in a recumbent tricycle.

13. Any contraindication to MRI. Including:

• Any intra-luminal implant, filter, stent or valve replacement

• Any type of life assist device, pump, or prosthetic

• Any vascular clip or clamp

• Any surgically placed clips or clamps or bands on visceral organs

• Any intracranial implants of any type other than dental fillings

• Any non-removable piercings, jewelry, or medicinal patch

• Any personal history of intraocular injury or fragment in or around the orbitthat cannot be cleared through radiologic examination.

• Any personal history of bullet, shrapnel, or stabbing wounds that cannot becleared through radiologic evaluation.

• Inability to lie flat in the MRI scanner for 60-90 minutes.

• participants who cannot complete the MRI will not be excluded fromparticipation in the remainder of the study procedures if they meet thoseinclusion and exclusion criteria

14. Use of any investigational agent within 4 weeks of enrollment, except open-labelextension phase.

15. Females: pregnant, lactating, or planning to become pregnant during theirparticipation.

16. Any medical condition, in the opinion of the investigator that will interfere withthe safe completion of the study.

17. Parents/guardians or participants who, in the opinion of the Investigator, may benon-compliant with study schedules or procedures.