Please assess the completion status of the following clinical trial:

Trial Title: Role of Skeletal Muscle Nitric Oxide Production in Age-related Fatigue and Fatigability

Study Design Characteristics:
- Allocation: RANDOMIZED
- Intervention Model: PARALLEL
- Observational Model: None
- Primary Purpose: TREATMENT
- Time Perspective: None
- Masking: TRIPLE
- Phase: None
- Number of Arms: 4.0

Eligibility Criteria:
Inclusion Criteria:~* 1. Age 20-35 yrs, and 60-80 yrs.~* 2. Ability to sign consent form (score \>23 on the 30-item Mini Mental State Examination, MMSE)~* 3. Stable body weight for at least 3 months~Exclusion Criteria:~* 1. Physical dependence or frailty (impairment in any of the Activities of Daily Living (ADL), history of falls (\>2/year) or significant weight loss in the past year)~* 2. Exercise training (\>2 weekly sessions of moderate to high intensity aerobic or resistance exercise)~* 3. Pregnancy~* 4. Significant heart, liver, kidney, blood or respiratory disease~* 5. Peripheral vascular disease~* 6. Diabetes mellitus or other untreated endocrine disease~* 7. Active cancer~* 8. Use of nitrates~* 9. Recent (within 6 months) treatment with anabolic steroids, or corticosteroids.~* 10. Alcohol or drug abuse~* 11. Severe depression (\>5 on the 15-item Geriatric Depression Scale, GDS)~* 12. Cardiac abnormalities such as a cardiac shunt or previously diagnosed pulmonary hypertension.~* 13. Systolic blood pressure \<100 or \>150, diastolic blood pressure \<60 or \>90.

- Gender: MALE
- Minimum Age: 20 Years
- Maximum Age: 80 Years
- Healthy Volunteers: t

Study Arms:
- placebo sildenafil young (Type: PLACEBO_COMPARATOR): Younger subjects (ages 20-35) were administered placebo sildenafil orally daily for 1 week.
- sildenafil young (Type: EXPERIMENTAL): Younger subjects (ages 20 -35) were administered sildenafil daily (25 mg/day) orally for 1 week.
- placebo sildenafil older (Type: PLACEBO_COMPARATOR): Older subjects (ages 60-80) were administered placebo sildenafil orally daily for 1 week.
- sildenafil older (Type: EXPERIMENTAL): Older subjects (ages 60 - 80) were administered sildenafil daily (25 mg/day) orally for 1 week.

Based on this trial design, predict the completion outcome and termination type (if applicable).