Parkinson's disease (PD) is a progressive and chronic neurodegenerative disease, which presents signs and symptoms both motor (impaired gait, posture, balance, etc.) and cognitive (memory loss, dementia, etc.), all of which are causing disability and assuming a high economic cost. This pathology is characterized by the destruction, due to still unknown causes, of the dopaminergic neurons, which are found in a region of the brain called the basal ganglia, specifically in a part of the brainstem called the substantia nigra. These neurons act in the central nervous system and use dopamine as primary neurotransmitter, responsible for transmitting the necessary information for the correct control of movements. For this reason, the result of destruction involves slowing of movements along with lack of coordination. These processes cause multiple deficits in higher cortical functions, affecting the motor and cognitive capacity of the individual and, therefore, negatively affecting the execution of both basic and instrumental daily activities. PD is the second most common neurodegenerative disease after Alzheimer's and it presents in both sexes in a similar way, with a slight predominance in men. The World Health Organization already estimated in 2005 a global incidence of 4.5-19 new cases per year per 100,000 inhabitants and a global prevalence of 100-200 cases per 100,000 inhabitants, while a more recent report published by the European Parkinson's Disease Association estimates a worldwide prevalence for the year 2030 of between 8.7 and 9.3 million people. 70% of patients are people over 65 years of age, and 15% of all those affected are adults under 45 years of age. As a general rule, PD affects 1% of the population over 60 years of age, 2% of those over 70 years of age, and 3% of those over 803. Due to all the physical and psychological consequences that can occur, the economic impact of this type of neurodegenerative pathology in the family nucleus is really great. The average annual expenditure per family unit for the different neurological pathologies is 13,063 euros. On the PD, the amount is established up to the figure of 9,219 euros per year. This expense is usually progressive according to the degree of advancement of the disease, averaging an expense of 7,146 euros in the incipient phase of the disease, going through 8,491 euros in the intermediate phase and reaching 14,443 euros in the advanced phase. From all this it can be deduced that families are currently the main providers of support services for this type of patient, causing a very high cost for them. In this sense, it is important to highlight that a large percentage of patients have had to change their address or have had to carry out reforms to adapt the home to their situation (bathroom, adjustable bed, crane, restraints or barriers for the bed, among others).

Currently, there are already certain authors who have shown how a high intensity interval training (HIIT) protocol produces improvements in cognitive and physical performance in healthy adults and in people with multiple sclerosis. These training programs are of a unimodal nature, that is, specific exercises for a specific joint and muscle group such as jumping, rowing, running or lifting weights, among others. However, another modality has been created, such as high-intensity functional training (HIFT), which can benefit different populations, both healthy and pathological, due to the multimodal nature of the exercises. These are prescribed knowing the target group and involve the whole body using universal motor recruitment patterns in multiple planes of movement such as squats. Thanks to multimodality, more aspects such as agility, coordination and precision of movements are worked on compared to unimodal HIIT programs that make this relevant work difficult in a person's daily life. However, the functionality of the exercises provides added value, since it improves the motivational factor, which in turn increases adherence to the program and the obtaining of health benefits. The current study aims to demonstrate the effectiveness of a HIFT training protocol in a specific population, such as people with Parkinson's disease.