Participants will perform in-person controlled speed Hatha yoga 3 times per week for 24 weeks for a total of 72 sessions of 1 hour duration.

The Picture Sequence Memory Test measures episodic memory. Subjects are asked to recall an increasingly lengthy series of illustrated objects and activities that are presented in a particular order on the iPad screen, with corresponding audio-recorded phrases that describe them. Two learning trials are provided with sequence lengths varying from 6-18 pictures. The number of adjacent pairs placed correctly for trials 1 and 2 is converted to a point score. The average score is 101.1 with a standard deviation of 14.5 points. The maximum number of points available is 130 points.

The List Sorting test evaluates immediate recall and sequencing of different visually and orally presented stimuli, termed working memory. Pictures of different foods and animals are displayed with accompanying audio recording and written text and the subject is asked to say the items back in size order from smallest to largest, first within a single dimension such as animals or foods and then on two dimensions, that is with animals and foods combined. The test takes approximately seven minutes to administer. The participant's raw score is the number of items answered correctly in 85 seconds, with a range of 0-130. Average score is 101.9 with a standard deviation of 14.7 points.

The Pattern Comparison test measures processing speed by asking subjects to discern as quickly as possible if two objects presented side-by-side are the same or not. The items are presented one pair at a time on the iPad screen. The participant is given 85 seconds of response time (excluding any time needed for the given iPad to "load" the items) to respond to as many items as possible (up to a maximum of 130) time on the iPad screen, and the participant is given 85 seconds to respond to as many items as possible up to a maximum of 130. The test takes approximately three minutes to administer. The total number of points available is 130 points, with a mean of 101.3 and a standard deviation of 14.7.

Changes in executive function age-corrected fluid cognition composite score measured by the Dimensional Change Card Sort test, the Flanker test, Picture Sequence Memory test, List Sorting test, and pattern comparison test of the NIH Toolbox Cognition Module. The units of measurement are points with higher scores indicating higher levels of functioning. Scores 70 or below indicates significant fluid cognitive impairment, scores around 85 indicate below average fluid cognitive ability, scores at or near 100 are considered average, scores around 115 are considered above-average fluid cognitive ability, and 130 and above indicate superior fluid cognitive ability (top 2% based on the national Toolbox normative data).

The object of the test is to walk as far as possible for six minutes. The subject will walk at a normal pace around a marked course for six minutes. The subject may stop to rest and begin again at will. The distance covered indicates aerobic fitness. The further a person walks, the better their cardiovascular condition. The units are meters.

A one-repetition maximum test measures the maximum load that an individual can lift only a single time throughout the full range of motion of the chest press and leg press exercises using proper form. All subjects' one-repetition maximum values will be determined within four to five trials. The units of measure are kilograms. Testing is performed on computerized, pneumatic machines.

Peak muscle power is then measured at eight relative intensities (40, 50, 60, 70, and 80% of one repetition maximum) on the computerized pneumatic machines. For each repetition, the concentric phase is performed as fast as possible, and the eccentric phase lasts between 2 and 3 seconds. Power testing is done for the leg press and chest press, and the unit of measurement is Watts.

The ten-meter walk tests at habitual and maximal speeds will be performed using electronic timing gates. Participants will stand on a starting line, and the test will start after the investigator's "3,2,1, Go!" cue. Timing gates will be placed at the 2-m and 8-m marks to reduce the impact of acceleration or deceleration on the results. Participants will perform one practice trial and two actual trials for each test. The best of the two times for each test will be used for analysis. Units of measurement are seconds.

The five times sit-to-stand test will be used as a measure of functional lower body strength and power. Participants will be given 1 practice trial and 2 actual trials, each separated by a 1-minute rest. The lowest of these two trial times will be used for analysis. Power outputs for the test will be computed using the accepted equations. Units of measurement are seconds.

Upon verbal cue, the subject stands up, walks around a cone placed three meters from the front edge of the chair, and then returns to a seated position as quickly as possible. Time is measured in seconds. The faster the person completes the test the better the dynamic balance.

The Parkinson's Disease Questionnaire-39 is a 39-item self-report questionnaire that assesses Parkinson's disease-specific health-related quality over the last month across the eight quality of life dimensions and specific dimensions of functioning and well-being. Each question is scored from 0-4 points, with lower scores reflecting better quality of life.