Study: NCT04650217

Intervention type: DRUG
Group type: ACTIVE_COMPARATOR
Intervention: Carbidopa/levodopa
Description: L-DOPA is the immediate precursor of dopamine, is converted to dopamine in presynaptic dopaminergic nerve terminals, and enhances dopaminergic transmission in multiple brain regions. Subjects assigned to L-DOPA will begin with a Week 1 L-DOPA daily dosage of 150mg, or 1.5 25mg carbidopa/100mg levodopa tablets at 9am and placebo tablets at~1pm and 5pm. In Week 2 the L-DOPA daily dose will increase to 300mg (1.5 25mg carbidopa/100mg levodopa tablets at 9am and 5pm, with placebo at 1pm), followed by a Week 3 to 8 L-DOPA daily dose of 450mg (1.5 25mg carbidopa/100mg levodopa tablets three times daily). Subjects assigned to placebo will take 1.5 placebo tablets three times daily for three weeks. Individuals will be instructed to maintain the same timing of doses throughout the study. Individuals unable to tolerate an increased dose will have their dosage reduced to the maximum previously tolerated dose.

Intervention type: DRUG
Group type: ACTIVE_COMPARATOR
Intervention: Carbidopa/levodopa
Description: L-DOPA is the immediate precursor of dopamine, is converted to dopamine in presynaptic dopaminergic nerve terminals, and enhances dopaminergic transmission in multiple brain regions. Subjects assigned to L-DOPA will begin with a Week 1 L-DOPA daily dosage of 150mg, or 1.5 25mg carbidopa/100mg levodopa tablets at 9am and placebo tablets at~1pm and 5pm. In Week 2 the L-DOPA daily dose will increase to 300mg (1.5 25mg carbidopa/100mg levodopa tablets at 9am and 5pm, with placebo at 1pm), followed by a Week 3 to 8 L-DOPA daily dose of 450mg (1.5 25mg carbidopa/100mg levodopa tablets three times daily). Subjects assigned to placebo will take 1.5 placebo tablets three times daily for three weeks. Individuals will be instructed to maintain the same timing of doses throughout the study. Individuals unable to tolerate an increased dose will have their dosage reduced to the maximum previously tolerated dose.

Intervention type: DRUG
Group type: PLACEBO_COMPARATOR
Intervention: Placebo
Description: Carbidopa/levodopa matched placebo

Intervention type: DRUG
Group type: PLACEBO_COMPARATOR
Intervention: Placebo
Description: Carbidopa/levodopa matched placebo

Intervention type: BEHAVIORAL
Group type: ACTIVE_COMPARATOR
Intervention: Exercise training
Description: Subjects assigned t Exercise will exercise individually at their home on a program set each week by Dr. Sloan and the research assistant (RA) coach, who will work with the patient to ensure they train according to the program at the appropriate level of intensity. Subjects will select from a series of aerobic activities and for Weeks 1-2 will train at 55-65 percent of maximum HR as established during their qualifying CPET. In Weeks 3-4, they will increase exercise intensity to 65-75 percent of maximum HR, and in Weeks 5-12 they will train at 75 percent of maximum HR.

Intervention type: BEHAVIORAL
Group type: PLACEBO_COMPARATOR
Intervention: Exercise training
Description: Subjects assigned t Exercise will exercise individually at their home on a program set each week by Dr. Sloan and the research assistant (RA) coach, who will work with the patient to ensure they train according to the program at the appropriate level of intensity. Subjects will select from a series of aerobic activities and for Weeks 1-2 will train at 55-65 percent of maximum HR as established during their qualifying CPET. In Weeks 3-4, they will increase exercise intensity to 65-75 percent of maximum HR, and in Weeks 5-12 they will train at 75 percent of maximum HR.

Intervention type: BEHAVIORAL
Group type: ACTIVE_COMPARATOR
Intervention: Control
Description: Control will engage in a series of stretches and toning exercises designed to promote flexibility and improve core strength.

Intervention type: BEHAVIORAL
Group type: PLACEBO_COMPARATOR
Intervention: Control
Description: Control will engage in a series of stretches and toning exercises designed to promote flexibility and improve core strength.