Evaluation of Functional and Biochemical Effectiveness of a Strength Training Protocol in Parkinson's Disease

Primary outcomes

1. Timed Up and Go Test

   Time frame: 12 weeks

   Test developed to evaluate balance and functional mobility to determine the risk of falling. The test consists of timing how long it takes the subject to perform the action of standing up from a chair, walking 3 meters in a straight line, turning around, and sitting back down in the chair. An increase in the time taken to complete the test indicates worse outcomes.

2. Berg Balance Scale

   Time frame: 12 weeks

   Scale developed to evaluate balance and postural control. The scale consists of 14 items with Likert-type responses ranging from 0 to 4, where 0 represents the lowest level of function and 4 represents the highest level of function. Higher values indicate better balance control.

3. 10 meter walk test

   Time frame: 12 weeks

   Instrument used to evaluate gait speed in meters per second. The test consists of timing how long it takes the subject to cover a 10-meter straight path (to avoid acceleration-deceleration effects, 2 meters are added at the beginning and end of the path). An increase in the time taken to complete the test indicates worse outcomes.

4. 30 second sit to stand test

   Time frame: 12 weeks

   Instrument used to evaluate the strength and endurance of the lower limbs. The test is performed with a 43 cm chair without armrests; the number of squats the subject is able to perform in 30 seconds is counted. The higher the number of squats performed, the better the test results.

5. Parkinson's Disease Questionnaire (PDQ-39)

   Time frame: 12 weeks

   It is an instrument that evaluates the quality of life in patients with Parkinson's disease. It includes 8 areas: mobility, activities of daily living, emotional well-being, stigma, social support, cognition, communication, and bodily discomfort. Higher scores on the PDQ-39-SV scale indicate worse outcomes.

6. Mini-Mental State Examination

   Time frame: 12 weeks

   It is a widely used screening tool for assessing cognitive function. It is commonly employed to detect cognitive impairment and monitor changes over time in conditions such as dementia or following neurological events like stroke or traumatic brain injury. The total score ranges from 0 to 30. A higher score indicates better cognitive performance and less impairment.

7. Patient Health Questionnaire-9 (PHQ-9)

   Time frame: 12 weeks

   It is an instrument that assesses the severity of depressive symptoms. The total score range from 0 to 27. Each of the nine items is rated on a scale from 0 to 3, resulting in a minimum score of 0 (indicating no depressive symptoms) and a maximum score of 27 (indicating severe depression). Higher scores indicate greater severity of depressive symptoms.

8. Malondialdehyde (MDA)

   Time frame: 12 weeks

   MDA, measured in nanomoles per milliliter (nmol/mL), is a byproduct of lipid peroxidation and one of the most widely studied markers of oxidative tissue damage, particularly during exercise.

   Higher MDA levels indicate greater lipid oxidative damage, suggesting a more harmful oxidative environment. MDA levels will be assessed using ELISA according to the manufacturer's instructions.

9. 8-Hydroxy-2'-deoxyguanosine (8-OHdG)

   Time frame: 12 weeks

   8-OHdG is a marker of oxidative damage to DNA, typically measured in nanograms per milliliter (ng/mL) or nanomoles per liter (nmol/L).

   Elevated 8-OHdG levels reflect increased DNA oxidation, which is associated with cellular aging and neurodegenerative processes. Quantification will be performed using ELISA, following the manufacturer's protocol.

10. Total Antioxidant Capacity (TAC)

    Time frame: 12 weeks

    TAC reflects the overall antioxidant defense and is generally expressed in millimoles of Trolox equivalents per liter (mmol Trolox/L).

    Higher TAC values indicate stronger antioxidant capacity, suggesting a more favorable redox balance. TAC will be analyzed using ELISA in accordance with the manufacturer's instructions.

11. Neurofilament Light Chain (NfL)

    Time frame: 12 weeks

    NfL, measured in picograms per milliliter (pg/mL), is a well-established biomarker of neuroaxonal damage and neurodegeneration, released into extracellular fluids following axonal injury.

    Higher NfL levels indicate greater neuroaxonal damage, and thus worse neurological status. Levels of NfL will be determined using ELISA, following the manufacturer's recommendations.