BACKGROUND
The care policy for obese children in Congo is almost non-existent. The aim of this study was to determine acceptability, accessibility and effectiveness of physical exercise session form best suited to the care of obese young people attending school in Brazzaville. This is an intervention study carried out on 23 overweight students in eight secondary schools in Brazzaville. The participants have performed two physical exercise sessions (aerobics alone, followed by aerobics and muscle strengthening) one week apart. The accessibility and acceptability of the form of sessions was measured at the end of each session, and effectiveness through observed physiological changes. The data was collected by means of a questionnaire. The levels of effectiveness (68.88 versus 31.22; p = 0.02) and acceptability of the aerobic and strength training session were significantly higher than that of the aerobic session alone (60.9 versus 39.1; p = 0.03). The aerobic and strength training session appeared to be more effective and more acceptable compared to the aerobic session alone. It can therefore be recommended for the management of this obese adolescent population.
OBJECTIVE
this study whose objective is to evaluate the levels of accessibility, acceptability and effectiveness of a form of session adapted to obese and overweight students in schools.
METHODS
MATERIALS AND METHODS
Study protocol
This is a before-and-after, here and there, intervention study conducted with overweight students in schools in Brazzaville. The participants were subjected to two physical exercise sessions one week apart: the first, aerobics (alone) only, and the second, aerobics combined with muscle strengthening. The order of the sessions was drawn at random and one week before the intervention. The acceptability and accessibility of the sessions were measured at the end of each session with a questionnaire submitted to the students, while effectiveness was assessed through anthropometric and biometric measurements taken before and after each form of session. Written informed consent was obtained from obese adolescents as well as from parents in accordance with the principles of the Declaration of Helsinki. The study protocol was approved by the Scientific Committee of the Institut Supérieur d'Education Physique (ISEPS) of the Marien NGOUABI University of Brazzaville.
Participants
A total of 23 school-going adolescents were recruited from eight secondary schools in the three geographical areas of Brazzaville and took part in the study. These schools were selected on the basis of the following criteria: belonging to a geographical area of the city (north, south, centre), having a large number of adolescents to cover the required number for the age group studied, and being accessible to our interviewers. Subjects should meet the following inclusion criteria: be Congolese and enrolled in a secondary school in Brazzaville, be between 14 and 18 years of age, not suffer from a chronic disease, and not have a malformation that could affect their body composition.
Measures
The data were collected using a questionnaire that consisted of three parts: The first part included information on the identification of the students surveyed, the second part included data on the acceptability and accessibility of the form, and the third part recorded the anthropometric and biometric data of the respondents. The body mass index (BMI) was calculated as P/T2 (P is weight in kilograms and T is height in metres) and the anthropometric weight status defined according to International Obesity Task Force (IOTF) standards for each subject (Bahchachi et al. 2017). The curve passing through BMI equal to 25 at the age of 18 years defines the threshold of overweight, obesity included (IOTF 25) and the percentile curve passing through BMI equal to 30 at the age of 18 years defines the threshold of obesity. An A 300 refractometer (Atago, Japan) was used to determine urine density from the samples collected. Frequency meters were used to measure heart rate. Subjective perception of effort was measured using the Borg Perception Scale. The weight and height of the respondents were measured in light clothing without shoes, using a digital scale and a stadiometer respectively.
Variables studied
Three composite variables were used in this study: the level of accessibility, the level of acceptability and the degree of effectiveness of the session.
Conceptual aspects of the variables
The variable acceptability of obese adolescents to the practice of a session form covered six components, namely: a) average duration of practice; b) weekly duration; c) long-term duration; d) content of the session form; e) feeling; and f) frequency of practice. The accessibility variable was assessed according to five items: a) location; b) proximity; c) environment; d) equipment; and e) instructor.
Each of the responses is coded from 0 to 4 according to the number of modalities contained in each component: the maximum level of acceptability is obtained by adding the maximum scores of the six components which gives a total of 17. The session is acceptable if the total score is ≥ 13.6. For the score ˂ 13.6, the session is considered "not very acceptable".
In relation to accessibility, the optimal level is obtained by adding the maximum scores of the components which gives a total of 18. The session is accessible, if the total score is ≥ 14.4. It is less accessible when the total scores are ˂ 14.4.
The degree of efficiency is assessed according to: a) an exercise intensity between 70 and 85% of Fcmax; b) a percentage weight loss < 2%; c) an energy expenditure of 500 kcal to 650 kcal; e) a physiological index of thermal stress of 6 to 8 and a subjective perception of the Borg scale of 6 to 8. The session is said to be more effective when at least four of these components have retained normal values. Finally, the session is considered most appropriate for this population when at least two of the variables it covers (acceptability, accessibility and effectiveness) have the best modality.
Physical training sessions
Aerobic training session
The aerobic session lasted 75 minutes during which the participants worked at 65% and 75% of the theoretical Fcmax in the first phase and at 65% and 75% of the theoretical Fcmax in the second phase. The session was divided into : 1) a grip in 5 min, 2) a warm-up in 15 min; 3) aerobics for 40 min; 4) a relaxation 10 min and 5) a return to calm and regaining control 5 min.
The warm-up part of this session consisted of cardiovascular activation, joint mobilization and muscle warm-up. It was carried out using fast walking, slow running and jumping exercises followed by stretching. The aerobic part included right and left set up, alternating, chase step, lunch, jumping jack, squats, power jack, pelvic limb swings and moves. For each exercise, participants performed in two sets of 30 repetitions with 20 seconds of recovery time between exercises. Aerobic capacity was energy-targeted during this session.
Aerobic training session and muscular reinforcement
This session lasted 1 hour and a half and consisted of six different parts, namely: 1) grip in 5 minutes, 2) warm-up in 15 minutes; 3) muscle strengthening in 30 minutes; 4) aerobics for 25 minutes; 5) relaxation for 10 minutes and 6) a return to calmness and regaining control for 5 minutes.
During the session, the subjects worked at 65 to 70% of the theoretical Fcmax, then the intensity was slightly increased from 70% to 85% of the theoretical Fcmax.
During this session, the warm-up part focused on cardiovascular activation, joint mobilization and muscle warm-up. It was carried out using fast walking, slow running and jumping exercises followed by stretching.
The muscle strengthening sequence was organized in the form of a circuit. This circuit consisted of 12 workshops that can be grouped mainly into squats, push-ups, abdominals, sheathing and jumps. The squats, push-ups and abdominals were done in 2 series with 30 seconds of recovery. Each set consisted of 10 repetitions in the first phase, then 15 and 20 in the last phase. Sheathing was also performed in two separate series of 30 seconds of recovery. The series consisted of 20 seconds of effort in the first part and 30 seconds in the second.
The aerobic sequence included right, left, alternating, set up, lunch, jumping jack, squats, power jack, pelvic limb swings and moves. These exercises were performed in two sets of 30 repetitions / exercise with 20 seconds of recovery in between.
During the cycle, the improvement of aerobic capacity and endurance strength were aimed at improving energy and muscular strength respectively.
STATISTICAL ANALYSIS
The data was entered using EpiInfo version 7 software and the analysis was performed with SPSS version 22 software. All quantitative variables were expressed as mean ± standard deviation and quantitative variables as absolute frequencies with corresponding percentages. The Kolmogorov-Smirov test was applied to verify normality. Comparison of variables within each group was performed using analysis of variance with repeated measures followed by post-hoc testing when Anova was found to be statistically significant. Inter-group comparisons of relative changes in the variables after the intervention were performed using a one-factor analysis of variance followed by post-hoc testing when Anova was found to be statistically significant. Chi-square test followed by Cramer's V calculation to compare the proportions between aerobic session (alone) and aerobic session combined with strength training. The Kaiser-Meyer-Olkin (KMO) test was performed to determine the sampling equation and to interpret the relationship between different variables. Principal component analysis was used to transform the number of correlated variables into a smaller number of uncorrelated variables. The significance level for all tests was set at p < 0.05.
RESULTS
Subjects studied had a mean age of 16.13 ± 1.14 years with a mean height of 162.03 ± 3.72 cm and a body mass (BM) of 79.10 ± 6.91 kg. The mean resting heart rate (Fcr) and rectal temperature (Trec) were : 75 ± 4 bpm; 39.94 ± 0.19 °C.
Data recorded during training sessions (Table 2), were higher at the aerobic and strength training session than at the aerobic session (alone) for PEFBORG (p < 0.001) and ED (p < 0.001) and %PP (p = 0.03). Compared to the IPCT, the score obtained from the aerobic session (alone) was comparable to that of the aerobic and strength training session (4.33 versus 5.25) but was significantly higher than that of the session (6.48 ± 0.56 versus 6.44 ± 1.01; p = 0.03). No differences were observed in the physiological parameters (Fc, Fcmaxtheor and % Fcmax).
The level of accessibility to the aerobic-only and aerobic/muscular strengthening sessions was not significantly different (47.8 versus 52.2; p = 0.76). In contrast, the latter form of session was significantly more acceptable to the subjects studied (60.9 versus 39.1; p = 0.03). (Table 3). Table 4 of the main components shows the most suitable model of physical exercise session for obese students attending school in Brazzaville).
CONCLUSIONS
The purpose of this study was to determine the most appropriate type of exercise session for the management of obese children. Taking into account the effectiveness, the high level of accessibility of the aerobic session associated with muscle strengthening compared to aerobic alone, the results obtained show that the first session is the most adapted for the management of this obese population. The PCA results confirm the higher effect of the aerobic session combined with strength training on the parameters of the ED components, %PP, suggesting the significant values of the ED components after this session. However, it would be necessary to determine the beneficial effects of an intervention program combining aerobic exercise and strength training in obese patients.
