Metabolism of Obese Women Under Exercise and Recovery Hypoxia

Metabolic Alterations in Obese Women Undergoing High-intensity Physical Exercise Associated With Intermittent Recovery Hypoxia.

Obesity is characterized as a low-grade systemic inflammatory disease, which changes several pro-and anti-inflammatory cytokines. The practice of physical activity is a non-pharmacological method that results in the reduction of the systemic inflammatory state and, when associated with hypoxia exposure, may substantially improve this state. Deep-water running is highly indicated to obese for guarantee less joint impact and lower fatigue levels. In this way, the high-intensity exercise associated with intermittent recovery hypoxia in obese women will be investigated.

Obesity is characterized as a low-grade systemic inflammatory disease. With the increase in adipose tissue, several cytokines show alterations in synthesis and secretion, resulting in endocrine imbalances. The cytokines that most influence this process are adiponectin, which is anti-inflammatory and reduces its concentration during obesity. At the same time, the pro-inflammatory cytokines are tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6), which show a significant increase in the face of obesity. The practice of physical activity is a non-pharmacological method that results in the reduction of the systemic inflammatory state, altering the lipid profile and levels of both anti- and pro-inflammatory cytokines and the improvement of the individual's physical capacity. Due to the high joint overload and muscle stress, water exercises are recommended for obese individuals as it maintains motor stimulation with a low risk of injury. The training tied to running in a deep pool, also known as Deep Water Running (DWR), will promote advantages similar to running on the ground, such as improving aerobic capacity, avoiding impact and enabling the performance of exercise at high intensities lower levels of fatigue. The high-intensity exercise performance reduces the availability of oxygen to muscle cells, inducing the hypoxic environment, which causes stabilization of the hypoxia inductive factor 1 (HIF-1), promoting gene transcriptions related to erythropoiesis and angiogenesis. Thus, the present study aims to investigate the effects of high-intensity physical exercise associated with recovery hypoxia, observing both the inflammatory and lipid profile and the physical capacity of obese women grade I. For this, 45 women with obesity will participate in the study, divided into 3 groups: hypoxia, normoxia and control. All will perform body composition, food intake, hematological and lipid profile tests, plus the serum quantification of cytokines before and after the 8 weeks of physical training. Deep-water tied running (DWR) training will be periodized, high-intensity interval, with recovery in hypoxia or normoxia. Intermittent recovery hypoxia is expected to act as an additive effect on the use of oxygen by the muscle, resulting in an improvement in the hematological and lipid profile, aerobic capacity and changes in the inflammatory profile in obese women.

Participants will be randomly distributed into 3 groups: Control (Gcon), Hypoxia (GHyp) and Normoxia (GNor). Those in Ghyp and GNor won't be able to know which group they are.

The group will be only submitted to evaluations (body composition, hematological, lipid and cytokines profile, food intake, and maximal effort under treadmill and deep-water running) at the beginning and the end of the study.

During the intervention of 8 weeks the participants will have the deep-water running training under normoxia, but during the rest they will be under hypoxia (FiO2=13%).

During the intervention of 8 weeks the participants will have the deep-water running training under normoxia, and during the rest they will keep under normoxia (FiO2=20%).

4 efforts of tied deep-water running for 5 minutes at 100-110%Vo2max under normoxia with 5 minutes of passive rest under hypoxia (FiO2=13%) or normoxia (FiO2= 20%). Frequency: 3x/week for 8 weeks.

Changes in body mass index (BMI = weight measured(kg) / (height (m)²) evaluated pre- and post- intervention.

Changes in fat-free mass, fat mass and bone mineral content evaluated pre- and post- intervention. Dual energy x-ray absorptiometry (DEXA) will be use.

The red cells, hematocrit cells and hemoglobin will be evaluated pré- and post- intervention using a Radiometer-ABL 700 (Radiometer, Copenhagen, Denmark), and for erythropoietin evaluation an EPO Immunoassay ELISA kit will be used.

The erythropoietin will be evaluated with an EPO Immunoassay ELISA kit in pre- and post- intervention .

Changes in total cholesterol, triglycerides, HDL-cholesterol and LDL-cholesterol and blood glucose evaluated pre- and post- intervention, quantified by Total Liquiform Cholesterol Kit, HDL Cholesterol Kit and Liquiform Triglycerides Kit, from Labtest diagnóstica®, using an enzymatic system and absorbance spectrophotometer.

Changes in serum levels of cytokines IL-6, TNF-α, adiponectin, FBP4 and leptin will be evaluated pre- and post- intervention, by MILLIPLEX® Kit.

Physical tests performed pre-, after 4 weeks and post- intervention to assess aerobic physical fitness by incremental test in treadmill. The test aim to evaluate the anaerobic threshold (AT) and VO2peak in deep-water running.

Physical tests performed pre-, after 4 weeks and post- intervention to assess aerobic physical fitness by incremental test in treadmill. The test aim to evaluate the anaerobic threshold (AT) and VO2peak in treadmill.

A food record of three non-consecutive days: two days of the week and one day in the weekend. This evaluation will last eight weeks. The caloric intake, macronutrients and fiber will be evaluated over the intervention with Dietwin® software (São Paulo, Brazil).

The feed will undergo analysis through the NOVA Classification. By NOVA, food will be classified into four groups: Group 1 - Unprocessed or minimally processed foods; Group 2 - Processed culinary ingredients; Group 3 - Processed foods; Group 4 - Ultra-processed foods. For each category, the total calories ingested will be calculated, and later, represented in percentage (%) the participation of each food group in the general diet.

The rate of perceived effort (RPE) will be noted after each effort during all the training program. The Borg scale will be used.

For group hypoxia and normoxia the oxigen saturation will be followed during the rest with a pulse oximeter. The SpO2 will be noted after the end of the effort, after 2,5 minutes in rest and in the end of the rest.

The .internal load will be calculated using TRIMP, that is calculated multipling the RPE for the time in effort (TRIMP = RPE * time in effort), for each participant and training session.

Inclusion Criteria: Women Age between 25 - 45 years old; BMI between 30 - 35kg/m²; Not be on a diet; Not be on a physical activity program; Not be menopaused. Exclusion Criteria: Smokers; Alcoholics; Use thyroid medication; Carry out nutritional monitoring or in treatment for weight loss; Hypertension; Metabolical syndrome; Have any comorbidity associated to obesity; Drugs use.