Research shows that a modality known as HIIT can bring cardiorespiratory improvements to a wider audience
International recommendations for prescribing physical activities recommend a minimum of 150 minutes per week of moderate exercise or 75 minutes at vigorous intensity. But does following these recommendations guarantee a healthier life? In truth no. There is a consensus among researchers that 30% of people do not show cardiorespiratory improvements when subjected to traditional exercises, even following the recommendations. Furthermore: 10% of practitioners experience some worsening.
Based on this problem, Alex Castro developed a doctoral study, at the Faculty of Physical Education (FEF) at Unicamp, manipulating the intensity of exercise and proving that this factor can be fundamental to increasing the number of individuals with positive responses to physical activity. The research is guided by professor Mara Patrícia Traina Chacon-Mikahil at the Exercise Physiology Laboratory (Fisex), with funding from the São Paulo State Research Support Foundation (Fapesp) and the Unicamp’s Teaching, Research and Extension Support Fund (Faepex).
Castro focused his study on High Intensity Interval Training (HIIT). HIIT consists of performing exercises at an intensity close to maximum effort, for short periods (up to 4 minutes), alternating with moments of recovery, or active rest (low-intensity activities) of equal or shorter duration than the intense exercise. The total time of each training session can vary from 5 to 40 minutes and the frequency from 3 to 4 days per week depending on the objectives.
The researcher compared individuals undergoing HIIT and traditional training, which was less intense and without recovery breaks. While 22,8% of individuals undergoing traditional training did not respond positively to exercise, only 5,8% did not respond to HIIT. “HIIT is a more effective method for minimizing frequencyêof non-responders to the exercise”, he states.
According to the research coordinator, HIIT is a form of safe alternative training that provides a wider group of people with improvements in their cardiorespiratory capacity. "O The number of individuals who improve their oxygen consumption is more common in HIIT than in traditional aerobic training”, says Chacon-Mikahil.
During the research, 69 sedentary men aged between 18 and 30 years old underwent traditional training, in which they maintained a continuous heart rate of 70% of the maximum frequency, and HIIT, in which it was alternated between 50% and 90% of the maximum, both with 40 min sessions, 3 to 4 times a week.
The participants' responsiveness was assessed by directly measuring oxygen consumption, that is, the amount of oxygen they were able to capture from the air they breathed. “If the collection capacity is poor, the system may be overloaded. cardiovascular and respiratory, as the individual will have to increase frequency cardiorespiratory to get the oxygen you need. Well-conditioned people are able to capture good results in a more natural way”, highlights Castro.
Oxygen consumption therefore reflects cardiorespiratory activity, which in turn is an important indicator of longevity. “The greater the cardiorespiratory fitnesslaugh, minor the risk of premature death from any cause and the development of cardiovascular diseases”, explains Castro. "So it is important investigate consumption mámaximum oxygenêno and propose guidelines for exercise prescriptionciostechniques that make it possible to improve this parameter for most people.”
According to Castro, the novelty of the project is trying to individualize exercise prescription as much as possible.heat físico. "AND what we today call personalized exercise medicine. The data we have in the literature are generally based on average data from the population and do not meet the demands of a significant number of individuals”, he discusses.
Together with oxygen consumption analyses, blood, saliva and muscle tissue were collected before and after training. These samples are being processed by the project team, which includes scientific initiation students from the Institutional Scientific and Technological Initiation Scholarship Programs (PIBIC and PIBIC Secondary Education) at Unicamp, in National Biosciences Laboratory (LNBio/CNPEM), and will serve as a basis for thelowering the metabolism of these individuals, before training and in response to it.
The researchers intend, based on this analysis, find biomarkers that are predictors of responsiveness to training, indicating the individual's pre-disposition to respond to physical exercise even before starting to train. “Different metabolic characteristics can be diagnostic markers of responsiveness. The ideal is which we can identify the subject who is a non-responder beforehand, so that we can personalize and find the training that effectively brings benefits to him”, explains the researcher.
The researchers commented that the objective is that, in the future, it will be possible to identify, from a simple dosage, in blood or saliva samples, the individual's predisposition to exercise. “It is an easily accessible measure that can be done instantly and would indicate whether that person will adapt to international recommendations or whether they will need a new strategy.prescription giatraining,” explains Castro.
Internationalization
This semester, Castro continues his research, with a PDSE-Capes scholarship, at the Pennington Biomedical Research Center (PBRC), in Louisiana in the United States, in collaboration with researcher Claude Bouchard, professor Emeritus and international reference na investigation of exercise responsiveness. “He works in the areas of genetics, chronic non-communicable diseases and physical exercise. It investigates how genetics can explain an individual’s physiological response to exercise”, says Mara Patrícia.
The partnership with Bouchard is the result of Unicamp's Internationalization Program, which made it possible for Mara Patrícia, Alex Castro and the FEF Integrated Laboratory (LabFEF) employee, Giovana Vergínia de Souza, to go to PBRC in October 2016. With married projects, the group was approved in the teacher and employee notices for international mobility. “It was a very important experience. Thanks to this contact, Alex will be able to develop part of his research with Dr. Bouchard, who reference in our work area”, emphasizes the teacher.
