ABSTRACT
Objective@#To examine the effects of high intensity interval training (HIIT) on body composition and cardiorespiratory fitness of obese primary school students, so as to provide a theoretical basis and practical reference for HIIT exercise prescription in schools.@*Methods@#From August to December 2022, 25 obese children [age:(11.0±0.4)years, BMI:(23.3±0.8)kg/m 2] from a primary school in Shenzhen were recruited and divided into an exercise group ( n =13) and a control group ( n =12). After 12 weeks of exercise intervention [The durations of load period and intermittent period were 15 s, load exercise intensity was 100% maximal aerobic speed (MAS), and intermittent exercise intensity was 50% MAS, each time there were 2 groups× 8 rounds, and the rest between groups was 2 minutes, totaling 10 minutes, and 20 meter shuttle run test (20 m-SRT) was performed once every 4 weeks to adjust and update MAS], the changes in body composition and cardio respiratory fitness indexes of obese subjects before and after the intervention were compared.@*Results@#After the intervention, body weight, BMI, body fat, body fat percentage, and visceral adipose tissue area of obese subjects in the exercise group decreased from (55.6±6.2)kg, (22.7±0.6)kg/m 2, (41.8±6.9)kg, ( 23.4± 5.5)% and (102.4±39.0)cm 2 to (52.3±5.8)kg, (21.1±0.8)kg/m 2, (38.6±6.3)kg, (20.2±4.5)% and (84.2±26.9)cm 2, respectively( t =8.73, 10.96, 7.02, 4.92, 4.95, P <0.05). SBP decreased from (115.4±9.7)mmHg to (112.3±8.7)mmHg ( t = 2.96 , P <0.05). The content of skeletal muscle, 20 m-SRT and VO 2max increased from (21.3±5.3)kg, (21.6±4.9) times and (39.4±2.0)mL/(kg ·min) to (21.8±5.2)kg, (31.4±6.3)times and (43.6±2.6)mL/(kg ·min), respectively ( t =-3.33, -8.37, -10.56 , P <0.05).@*Conclusions@#HIIT is an effective way to improve the body composition and cardiorespiratory fitness of obese primary school students. It is recommended that schools with the necessary conditions use this method as an intervention measure to help reduce weight and improve cardiovascular health among obese students.
ABSTRACT
Objective To investigate the influence of different prompt measures on the quality of cardiopulmonary resuscitation (CPR) chest compressions in the standardized training of residents in Chinese medicine hospitals. Methods There were 84 participants who were the first year standardized training residents recruited from Guangdong Provincial Hospital of Chinese medicine during July to August 2016, and eleven of them were excluded because of incomplete chest compression data collected from the feedback system. Finally, 73 participants being volunteers were enrolled. They were divided randomly into phone metronome group (n = 16), music metronome group (n = 15), depth display group (n = 22), and blank control group (n = 20). In phone metronome group, a mobile phone metronome was applied in the duration of CPR, with a frequency of 110 beats per minute, beat 2/4; in the music metronome group, it was accompanied by the music Staying Alive during the compression period, with frequency of 107 beats per minute, beat 4/4; in depth display group, a model electronic displayer was used in the duration of the compressions to feedback the real time compression depth and its rebound situation in CPR; there was no any intervention measure in blank control group. Each participant performed 5 cycles of CPR on a manikin. A chest compression feedback device was placed on the pressing point, on which the participants places the hand for CPR. The chest compression fraction 1 (CCF1), compression depth, compression rate, too slow frequency, too fast frequency, too shallow frequency, the total times of compressions, the correct times of compressions, correct rate, and the rate of compression retention were record as preliminary evaluation data by using the dual sensor and the pressure sensor built in the chest compression feedback device. At the same time, the correct compression ratio, correct ventilation ratio, the chest compression fraction 2 (CCF2) displayed on the human electronic displayer of the manikin were used as the review criteria. The quality of chest compression among the four groups of volunteers was compared. Results The compression rate and the too fast frequency in the depth display group were significantly higher than those in the music metronome group [compression rate (bpm): 140.59±17.90 vs. 124.27±21.43, the too fast frequency (times): 134.18±49.88 vs. 95.40±53.76, both P < 0.05], and the total compression times in depth display group were significantly higher than either in music metronome group or in blank control group (times: 152.73±27.05 vs. 135.60±10.38, 144.60±12.56, all P < 0.05), the rate of compression retention in depth display group was significantly higher than that in blank control group [37.50% (4.75%, 88.25%) vs. 12.00% (2.75%, 47.00%)]. Consistency detection of two sets of feedback systems for chest compression showed that the chest compression ratio in music metronome group evaluated by the chest compression feedback device was obviously lower than that assessed by the analog human electronic displayer [(53.60±9.87)% vs. (58.20±28.17)%], and it was suggested that the chest compression ratio in depth display group evaluated by the chest compression feedback device be markedly higher than that assessed by the analog human electronic displayer [(56.32±7.77)% vs. (43.86±27.63)%, P < 0.05], and it was shown that the correct rates of chest compression assessed by the chest compression feedback device were significantly lower than those evaluated by the analog human electronic displayer in metronome, music, depth and blank control groups [phone metronome group: 0.00% (0.00%, 60.75%) vs. 38.50% (24.25%, 92.00%), music metronome group: 0.00% (0.00%, 7.00%) vs. 60.00% (32.00%, 89.00%), depth display group: 0.00% (0.00%, 0.25%) vs. 34.00% (20.75%, 68.25%), blank control group: 0.00% (0.00%, 1.75%) vs. 61.50% (30.75%, 84.25%), all P < 0.05], suggesting that the consistency of this two feedback systems be poor and their degrees of reliability low. Conclusion The effects of intervention measures on the quality of chest compressions vary from person to person, and the quality of chest compressions can be really elevated only by systematic training and repeated practice.