Research on Intelligent Analysis of Healthy Training Progress of Teenage Sports Athletes Using Various Modalities

Abstract

The study compared different training modalities, such as high-intensity interval training versus continuous endurance training, on selected health-related physical fitness, biochemical and haematological parameters of teenage players yielding similar mechanical work and training duration. A random sampling technique was employed and affirmed by the Ethical Committee of Sichuan Province, China. Forty-five teenage sports players aging 18–19 from Sichuan Province, China, were categorized into two experimental and one control group (n = 15) subjects. The groups were allocated separately to high-intensity interval training, continuous endurance training, and control group for a three-month physical exercise program. Each group’s training intensity was set based on the resting heart rate, to assess the effects on health-related physical fitness using fitness gram variables such as cardiovascular endurance, muscular endurance, and flexibility. Biochemical and haematological fasting blood samples were taken and tested at baseline and post three months of training. Detailed descriptive statistics were carried out for the interpretation of the data. All the statistical analysis was completed using the IBM SPSS 20. Paired t-test and one-way ANCOVA were used to evaluate the effect of two aerobic training methods, and to determine the exact difference between the groups, Scheffe’s post hoc test was employed. The result of the study shows that cardiovascular endurance in HIIT showed a better performance of (25.6%) than in C.E.T. (18.1%). Regarding muscular endurance, C.E.T. achieved 19.6% and HIIT 16.2%. For flexibility, HIIT improved by (6.5%) while C.E.T. (5.8%). Accordingly, the study revealed significant changes in teenage sports players’ health-related fitness, biochemical and haematological parameters.

1. Introduction

The primary reason for the rising health problem in children is physical inactivity. A rampant increase in childhood obesity is widespread across the globe, which has led to an alarming rise in various metabolic disorders. Recently, the World Health Organization declared obesity as a worldwide epidemic [1]. The trends of advanced technology have been highly associated with children spending more time on indoor events, such as watching television, playing with computers, playing video games, and hardly engaging physically [1]. Many fast-food outlets selling unhealthy food that lack nutrition are easily available to people. The consensus among researchers predicts an inactive lifestyle and unhealthy diet, leading to a rising trend of chronic diseases exhibited during teenagers’ growing period [1]. Subsequently, children are prone to elevated risk for many preventable acute and chronic medical problems related to increased morbidity and mortality. Moreover, psychosocial outcomes such as low moods, lower self-esteem, and depression, are incurred due to childhood obesity, which can be carried on into adulthood [2].

The two distinct areas for developing the physical fitness level are physical exercise (P.E.) and physical activity (P.A.), where P.E. is the sequence of exercises performed for the development of physical fitness and overall health, and P.A. is generally being conceptualized as activities that revolve around the moment and being active [2]. Obese children typically exhibit lower levels of P.A. or P.E. and tend to engage in more sedentary behaviors instead [1]. Sedentary behavior is an action requiring much less energy expenditure [2]. People opting for more are being inactive and choosing to engage in activities requiring less effort like sitting or lying [1,2]. Physical exercise is a factor that is often neglected by many Chinese school systems despite its numerous health benefits [3]. Existing evidence points toward a physical inactivity epidemic among children and youth in China, where a paramount proportion of this population does not meet P.A. guidelines despite the health benefits being acknowledged [1,3,4].

2. Need for Physical Activity

P.A. is conclusively associated with physical fitness, e.g., strolling, running, gardening, cycling, swimming, and domestic errands [4,5,6]. The American College of Sports Medicine (ACSM) (2009) additionally indicates that no less than 30 min physical activity should be pursued daily, at least thrice every week, to yield remarkable health advantages. The World Health Organization (WHO) (2009) also recommends ten thousand strides each day for advancement in fitness. According to Gualano et al. (2022), physical inactivity has been rapidly increasing, estimated at 31% of the world population [7]. Through decades of research, it has been found and proven that cardiovascular, metabolic, and cancer diseases can be prevented since physical activity is established to protect against them [8,9,10]. Physical exercise also helps improve the psychological well-being with self-esteem, and coping with anxiety and depression [1,8,9]. ACSM and American Heart Association (A.H.A.) guidelines also recommend and encourage participation in multidimensional physical activity programs for children and older adults, insisting on strengthening, flexibility, and balance exercises ranging from moderate to vigorous combination intensities [3,4,11].

3. Concept of Health in Physical Fitness

Most people think they are healthy just because they are not sick [5,12]. The WHO defines health as complete physical, mental, and social well-being and not merely the absence of disease or infirmity [5,12]. Health, at the optimum of well-being, is referred to as the quality of life (Q.O.L.) [5]. Freedom from disease is a vital part of health but not the spectrum’s only constituent [5]. What is acquired from optimum health is high-level mental, social, enthusiastic, profound, and physical health inside the cut-off points of one’s heredity and individual capacities [3,4,11,12].

According to Haapala et al. (2020): “Health is the ability to access and apply resources from the six dimensions of health to the experiences of daily living, thus assuring growth and development and the sense of well-being that it affords”. The six dimensions of health are physical, emotional, social, intellectual, spiritual, and occupational [4]. Like the first, this definition does not mention the absence of disease as an indication of being healthy but confirms that health is a composite situation. It also indicates that health is not static; it could change in the next moment, positively or negatively, depending upon the input or action we make today [3,4,11].

4. Importance of Improving Health-Related Physical Fitness Components

Physical fitness is an integrated measure of various other factors, as the body system overall is involved in performing daily activities and exercises [13]. Health-related physical fitness (HRPF) comprises body composition, cardiorespiratory endurance, flexibility, muscular strength, and endurance [14] and this is often referred to as the characteristic of health-related components related to health promotion and preventing diseases [14,15]. It is noted that health and fitness are related directly to where overall health benefits are reaped [14,15]. More so, controlling weight, physical fitness can elevate moods, boosts energy, ensures proper sleep, and increase immunity against diseases [13,14,15].

Remarkable physiological and psychological changes occurring during childhood and adolescence phases describe the important stages of life and lifestyle as the habit procured during this period depicts and influences an individual’s life and health [13]. High abdominal adiposity and an increase in body fatness has also been associated with low physical fitness in children [16] making it vulnerable to several cardiovascular disease risk factors [3,11,16,17] and high blood pressure [4]. Thus, there is a need for emphasizing the promotion of the development of high fitness levels in children and youth.

5. Components of Health-Related Physical Fitness

Physical fitness encompasses cardiorespiratory, metabolic, morphological, muscular, and motor components [18]. Thereby, physical educators classify physical fitness into two categories, which are: skill related fitness and health-related fitness [18,19]. The first is related to sports performance, and the second is associated with disease prevention and health promotion, which include cardiorespiratory endurance, muscular strength and endurance, body composition and flexibility [18,19].

Most studies have established that excessive fat in children is linked to low health-related fitness [16,18,19]. Healthy/unhealthy lifestyles are developed during the early stages of growth and these are further carried forward to influence behaviors and health statuses in the future [14,15]. Many researchers [3,4,11,13,18] have deliberated that the need for physical exercise demands nowadays is quite different from the past decades’ requirement due to the speedy changes in people’s social and economic life [4,5,6]. In the past, the typical regimen of regular living included vigorous work and activity, which indirectly benefitted health. Children used to walk to and from school because of the lack of transportation and were seen more often outside for play as toys such as electronic devices were not introduced to them [4]. Today, many parents restrict children from visiting their neighborhoods, thus restricting and protecting their children from the fear of the unknown and for safety purposes [6].

High-intensity interval training improves aerobic capacity among healthy and active college men [3,11], sedentary men, futsal players and obese youth [20]. Roxburgh et al. (2014) made a comparison and realized that HIIT is seen to be superior in its effect than moderate continuous training in congenital heart defects (CHDs) patients when measured on ventilatory markers and cardiac efficiency. Roxburgh et al. (2014) examined A.I.T. and C.E.T. on VO_2max, high-density lipoprotein (HDL) and triglyceride in patients with metabolic syndrome and post-infarction heart failure [20]. Castelli et al., 2007, in an earlier study to determine if CMIET was more effective than a HIIT single bout in improving VO_2max in sedentary people, confirmed that the comparison of the effectiveness of the HIIT with C.E.T. for school boys has not yet been studied [21].

Therefore, the study’s main aim was:

• To compare the effect of HIIT and C.E.T. on selected HRPF variables such as cardiovascular endurance, muscular endurance, and flexibility among teenage boys.
• To compare the effect of different training modalities on the lipid profile of boys.
• To compare which training influences hematological variables such as red blood cells, white blood cells, and hemoglobin, among boys.

6. Related Literature

Castelli et al. (2007) performed a study to find “the relationship between physical fitness and academic achievement in children”. Children between third to fifth grades from four schools were chosen after the selection procedure, a total of n = 259 were screened out of 582 children across these schools. The evaluation of the children was conducted with the ISAT test for academic achievement and fitness for health-related physical fitness. The collected data were analyzed using Pearson’s product movement correlation to find out the status of effectiveness on each other. The analysis showed a positive correlation between the pacer test, push-ups, and curl-ups with ISAT test at p < 0.01, while sit and reach were correlated with total academic and math achievement. M.I.A negative correlation was indicated between the B.M.I. and three academic achievement tests at p < 0.001. Thus, the investigation results depict that children with good physical fitness can achieve more on academic achievement tests [21].

Van Dusen et al. (2011) examined an “Association of physical fitness and academic performance among school children” in Texas [22]. In all, 254743 children were selected through grades 3–11 from 13 schools evaluated using the T.A.K. test for academic achievement and fitness for fitness. The study outcome shows that B.M.I. had a significant positive link with academic achievement. It was also found that the association of cardiovascular fitness with academic achievement was found to be most robust, with 0.17 in boys for T.A.K. math test and 0.27 for T.A.K. reading test; 0.33 for the T.A.K. math test in girls at 95% CI. Next were curl push-ups sit and reach, while the weakest link was in the trunk lift at 0.07. Therefore, from this study, it was concluded that more physical education periods and encouragement of practitioners should be increased and directed toward the development of cardiovascular fitness. It is because it is powerful and significantly linked up with academic performance in children where the phase of late middle school to early high school is simultaneous with the peak development period.

Eveland et al. (2009) studied the interconnection of physical fitness to the academic performance of elementary children in grades three, four, and five. For the study, 134 children were selected who were assessed in the fitness variables one-mile run, B.M.I., curl up and sit and reach and academic achievement. The data was collected through the Terra Nova achievement test based on mathematics scores and the reading/language arts section. The data information analysiswas done using the PPMCC and Fisher’s r-to Z transformation at p < 0.05 level of significance. The result shows a significant negative correlation (r = −0.28), which interpreted that those who ran faster scored higher in their mathematics scores [23].

In contrast, no significancewas seen in reading/language 1-mile run, B.M.I. to academic achievement. Muscular fitness (sit and reach and curl up) show a positive correlation (r = 0.20) with mathematics scores but no significant relation with reading/language arts scores when looking at the gender-based, it was found that boys showed no significant, but in girls, there was a negative correlation of r = −0.31 for 1mile run and reading/language and r = −0.36 for 1-mile run and mathematical scores. Thus, from the study, it was evident that physical activity helps enhance children’s academic performance. In girls, one-mile run and muscular fitness have shown more significant effects and outcomes in academic achievement.

Faigenbaum et al. (1999) piloted an exploration to determine the development of muscular strength and endurance in children aged 5.2 to 11.8 years, due to two types of resistance programme low repetition- heavy load and high repetition- moderate load [24]. A total of 44 children (11 girls and 33 boys) participated in the study. Randomly assigned to LRHL = 16 (five girls and 11 boys); HRML = 16 (four girls and 12 boys); control = 12 (three girls and nine boys) involved in the intervention programme for 8 weeks/twice weekly. The testing of muscular endurance and muscular strength was carried out based on the 1RM protocol. The pre-test, mid-test (after 4 weeks) and post-test (after 8 weeks) were performed, respectively. Chest press and leg extension were used to measure the strength and endurance of the lower and upper body. It showed an increase in strength practicing LRHL by 31.0% and HRML by 40.9% for the lower body and showed significance in both training groups. When LRHL and HRML were equated to the control group, muscular endurance significantly increased. HRML also showed greater gain (13.1 ± 6.2 rep) when compared to LRHL (8.7 ± 2.9 rep) for lower body endurance at (p = −0.2 ≤ 0.01). In upper body endurance, there was no significant between control and LRHL. In contrast, HRML showed a significant gain over control by 16.3% (8.7 ± 2.9 rep). Thus, HRML seems to be more favorable for children during the adaptation phase. The improvisation of muscular endurance and muscular strength is possible from preadolescence.

Flanagan et al. (2002) examined two different modes of strength training, i.e., machine and own body weight in children aged 8.64 ± 0.49 to 8.75 ± 0.46 years [24]. Fifty-eight students (28 boys; 30 girls) participated in the study and had no experience of strength training in the past. They were assigned to three groups; machine trained groups (n = 14); body weight trained (n = 24), and control (n = 20) who did not receive any training. The training lasted for 11 weeks and testing on medicine ball throw, standing broad jump and shuttle run was conducted before the start of the training intervention and after the completion of 11 weeks. The 2 × 3 ANCOVA was used to analyze the data. The result shows a significant increase in the medicine ball throw in the body weight trained group while there was an increase in the machine trained group but could not make a significant difference. In the other variables, the long jump and shuttle run, an improvement was seen in that children engaging in strength training were safe and effective if the training principles are followed appropriately.

Lambrick et al. (2016) discovered “the effectiveness of a high-intensity games intervention on improving indices of health in young children”. Fifty-five children (32 boys: 23 girls) between 8 to 10 years old were selected for the study for6 weeks. The children were a mixture of normal and obese B.M.I. All the participants were assessed at the baseline and followed up on graded exercise tests, submaximal exercise tests, and body composition. The data show the children involved in H.I.G. had improved peak oxygen consumption (VO_2max) 51.4 ± 8.5 (pre) to 54.3 ± 9.6 (post) mL·kg⁻¹·min⁻¹, peak running speed 11.3 ± 1.6 km·h⁻¹ (pre) to 11.9 ± 1.6 km·h⁻¹ (post) and oxygen cost reduced at p < 0.05. In obese adolescents, waist circumference significantly decreased and improved muscle mass. Thus, the study demonstrated a positive effect on physiology and body composition, indicating the health status of normal and obese children due to high-intensity games intervention [25].

Milanovic et al. (2015) compared the effectiveness of VO_2max based on meta-analysis and systematic reviewing manuscripts on endurance training and HIIT [26]. Meeting all the inclusion criteria, 28 studies were analyzed. The criteria included sedentary men and women, untrained and healthy, aged between 18 and 45. The risk of biases was evaluated using PRISMA, with three reviewers assessing k- statistics at 0.95. VO_2max meta-analysis comparison between trained and control was 4.9 mL·kg⁻¹·min⁻¹ ± 1.4 mL·kg⁻¹·min⁻¹; HIIT and control 5.5 mL·kg⁻¹·min⁻¹ ± 1.2 mL·kg⁻¹·min⁻¹; HIIT and endurance training 1.2 mL·kg⁻¹·min⁻¹ ± 0.9 mL·kg⁻¹·min⁻¹. So, the result of the study shows that the training significantly improves VO_2max but HIIT shows more elicit for substantially greater improvement.

Perry et al. (2008) directed a study to find the VO_2max [27]. For the study, eight subjects (female-three and male-five) aged 24 ± 1 years participated in 6 weeks of HIIT three times a week to know its effect on VO_2max. The training involved 10 repetitions × 4 min at 90% VO₂ peak on cycle ergometer trailed by 2 min passive recovery between bouts. A volitional exhaustion test was conducted at baseline and post-training to analyse VO_2max. In addition, 1h cycling at 90% and 60% were performed. The result of the study shows an increase in VO_2max by 9% following HIIT protocol in participants.

Boreham et al. (1997) studied 24 obese (BMI = 30.0–39.9) schoolboys aged between 11–14 years on their aerobic capacity following high-intensity intermittent training. The training was conducted for 8 weeks on three alternate days, n = 12 boys, were involved in the training while the other n = 12 functioned as the control group. Exercise intensities were fixed at 100–130% using the M.A.S. criterion exercise lasting for 30 min. The significance of the training protocols was analyzed using the ANCOVA. Aerobic capacity in children practizing HIIT significantly improved by 7.27%, while only a 0.86% change was observed in the control group. Thus, 8 weeks of HIIT in obese school boys effectively improves aerobic capacity [28].

Roxburgh et al. (2014) conducted a study to determine if continuous moderate-intensity exercise training (CMIET) is more effective than combined HIIT single bout in improving VO_2max in sedentary people. In all, 29 participants (male: 10; female: 19), aged between 36.25 ± 6.87 years, were selected and randomly divided into CMIET (n = 7); CMIET + HIIT (n = 7) and control (n = 7). CMIET and CMIET+HIIT attended the fivetraining sessions/week for 12weeks. Pre- and post-testing were carried out on VO_2max. The training was conducted in a control structure CMIET walked 15 min treadmill and 15 min cycling on a cycle ergometer at 45–60% intensity of H.R.R. CMIET + HIIT group performed four sessions of MIET and one session of HIIT of 8 × 60 s work at 100%: 150 s active recovery on the treadmill. The ANCOVA and Tukey post hoc tests were used to analyze the result. After 12 weeks of intervention, relative VO_2max in CMIET + HIIT increased by 10.1%; CMIET-3.9%, while in the sedentary control group, VO_2max decreased by 5.7%. Statistically, a significant difference was found between the influence of CMIET + HIIT and CMIET on VO_2max [20].

Vega et al. (2013) conducted 8 weeks of circuit training on (n = 37) school children and (n = 35) functioned as the control group and aged between 10–12 years [29]. The participants were involved in the training programme for 4 weeks, two sessions/week, and during the maintenance phase, they attended two circuit training sessions per week. The control group involved themselves in their traditional activities but was not allowed for a structured fitness regimen. Baseline and post-test were executed to discover the effect of the training on cardiovascular endurance and muscular endurance. The two-way ANCOVA and Bonferroni were used for the analysis of data. A significant difference was witnessed in the experimental group compared to the control group. The experimental group increased pre to post-test at p = 0.015, while the control group saw no significant difference at (p ≤ 0.975) on cardiovascular endurance measured with a 20m shuttle run test. Furthermore, the muscular endurance of the abdomen 30 s sits up test was tested, which showed significant improvement at p = 0.026 and no significance was found in control with p = 1.000. Thus, the study concluded that circuit training effectively increases and maintains aerobic capacity and develops muscular endurance in schoolchildren.

Simar et al. (2012) conducted a study to examine the effect of exercise on hematological parameters [30]. Meeting all the criteria, n = 37 was selected for the task of aged 19–35 years and categorized as trained (who exercised at 10 metabolic) and untrained (who could not complete more than five metabolic equivalents) in the past 12 weeks. Assessment of VO_2max was carried out by cardiopulmonary testing, so 30 min prior and within 30 min of assessment, the blood sample was withdrawn to see the effect pre- to post-exercise of complete blood count. A significant difference was found in both trained and untrained individuals on hemoglobin, hematocrit, and platelets following exercise, while WBC remained unchanged from hemoglobin pre (14.5 ± 0.3) to post (15.0 ± 03); hematocrit pre (43.8 ± 0.8) to post (45.0 ± 0.9); platelets (228 ± 10) to post (253 ± 11). While comparing trained and the untrained individual had a greater increase in hemoglobin (14.3 ± 0.3 to 15.2 ± 0.4) when compared to trained (14.7 ± 0.4 to 14.7 ± 0.4). Therefore, it indicates that exercise changes blood parameters with an increase in hemoglobin, hematocrit, and platelets in no matter of gender or fitness levels.

Welk et al. (2010) conducted a study in Texas to examine the association between health-related fitness and academic performance in school children. The data was collected from the schools with the help of teachers training on fitness gram on two batteries, i.e., for VO_2max; the progressive endurance run or the one-mile run and B.M.I. The assessment was carried out by Texas assessment knowledge and skills test for academic performance. The data of 36,835 were analyzed, representing 1053 districts; 6365 schools and justifying the sample and based on exclusion criteria, 2157 were excluded. The participant included were elementary n = 19,948; middle school n = 8916 and high school n = 1373. Mean, SD, partial correlation and mixed model regression were used to analyze the data. The result of the study showed a positive relationship between the fitness of children and their academic performance. It was also seen that the higher fitness rates also helped the school achieve much more and get more recognition [31].

7. Hypotheses Formulation

In the light of the other academic literature reviewed, these following hypotheses have been developed for this study:

H1: 

There would be significant changes in HRPF parameters such as cardiovascular endurance, muscular endurance, and the flexibility of boys due to 12 weeks of HIIT programme.

H2: 

There would be significant changes in HRPF parameters such as cardiovascular endurance, muscular endurance, and flexibility of boys due to 12 weeks of C.E.T. programme.

H3: 

Significant changes would be seen in biochemical variables such as T.C., T.G., HDL, LDL, and the VLDL of teenage boys due to 12weeks of HIIT programme.

H4: 

Significant changes in biochemical variables T.C., T.G., HDL, LDL, and VLDL would be observable in teenage boys due to 12weeks of C.E.T. programme.

H5: 

There would also be significant changes on selected hematological variables such as hemoglobin, WBCs, and the RBCs of boys due to 12 weeks of HIIT programme.

H6: 

There would also be significant changes in selected hematological variables such as hemoglobin, WBCs, and the RBCs of boys due to 12 weeks of C.E.T. programme.

H7: 

There would be a significant difference between the training effects of HIIT and C.E.T. on health-related physical fitness, biochemical, and hematological parameters of boys.

8. Research Methodology

This research aims at investigating the impact of different healthy training modalities on selected HRPF biochemical and hematological parameters of teenage boys. This study involves an exhaustive study of different training modalities, such as HIIT and C.E.T. The research was carried out through proper sports training methods. Research on H1IT and C.E.T. show physiological benefits. Still, more research is needed to identify the length and intensity of the HIIT and C.E.T. protocol for achieving health outcomes. Many recent studies discuss the future studies needed to fulfill the efficacy of HIIT and C.E.T.in the real world. The research methodology must be well-founded to minimize data collection and analysis errors. For this study, standardized equipment was used for the data collection.

9. Selection of Subjects

A convenience sample technique was adopted to select the subject in this study. The sample was decided, 45 healthy teenage boys aged 18–19 years from China, who had voluntarily taken part in the study. Completing two-week introductory sessions in the HIIT and C.E.T. to familiarize with the exercise and techniques was the eligibility criterion for participating in the study. All the subjects included in the study were healthy and participated in weekly three times training. In the beginning, the investigator explained all the potential risk factors and the benefits of the study to the participants and their parents and made them sign the consent form. The study design was randomized and controlled to compare the influence of two distinct types of training modalities on teenage boys. After the screening, random sampling techniques were used to select the subjects according to the three groups: HIIT, C.E.T., and C.G. The random computer number generator was used to generate the randomization code. In completing the investigation, the training groups were set to compliance with 80% of the training program. The studies with the objectives of HIIT and C.E.T. effects on health-related physical fitness, biochemical, and hematological parameters of teenage boys were searched in an electronic database, including Science Direct, research papers from national and international journals, PubMed, Google Scholar, and Books.

10. Investigational Design

The study design was a quasi-experimental study where the independent variable was the number of sessions in HIIT and C.E.T.in a week; the dependent variables were health-related physical fitness, biochemical, and hematological parameters. All subjects were classified into two experimental groups and a control group of (n = 15) subjects. The groups were allocated separately to HIIT, C.E.T., and C.G. Each group’s training intensity was fixed, based on their resting heart rate. The pre-test was administered to all subjects before the investigation, and the post-test was administered following the training session. Health-related physical fitness factors were collected, including cardiovascular endurance, muscular endurance, and flexibility information. The biochemical factors such as T.G., HDL, LDL, and VLDL, the hematological variables such as hemoglobin, R.B.C., and WBC, and pre- and post-tests were taken individually during the 12-week training program for all three groups. The experimental group was not permitted to participate in any training program, except the control group, during the data collection.

11. Statistical Analysis

The data obtained were analyzed and tabulated for further statistical analysis. All the statistical analysis was completed using the IBM SPSS 20 for Windows. At first, the mean and standard deviations were calculated [16]. The data were normalized using logarithmic alteration after the normality distribution was checked. Data were analyzed for all the groups (HIIT, C.E.T., and C.G.). The difference between the three groups (HIIT, C.E.T., and C.G.) was checked. For that, the pre-post changes within the groups were compared with paired sample t-test. The next step was to determine if there was a difference between the groups, ANCOVA F-test was used. ANCOVA was analyzed to determine the significant difference between groups based on scores. The statistical significance was set up at p ≤ 0.01 and p ≤ 0.05 for analysis.

12. Results and Discussion

Computation of Health-Related Physical Fitness Variables

The data obtained from the analysis of paired t-test, pre-test, and post-test means of HIIT, C.E.T., and control groups, on cardiovascular endurance have been detailed in

Table 1. The descriptive statistics, paired t-test analysis of Co-Variance (ANCOVA), Scheffe’s post-hoc test for paired mean difference of Cardiovascular Endurance of HIIT, C.E.T. and control groups (* Significant; ^NS Not Significant).

Traning Groups	Pre-Test			Post-Test			t-Ratio		Significance
	Mean		SD	Mean		SD
HIIT	44.93		7.42	56.46		6.86	11.88 *		0.000
C.E.T.	45.33		13.49	53.53		13.29	14.58 *		0.000
C.G.	43.46		10.50	44.60		9.17	1.83 NS		0.087
Groups	HIIT	CET	C.G.	SOV	Sum of Squares	df	Mean Square	F-Value	Significance
Pre-test Mean	44.93	45.33	43.46	B	28.97	2	14.48	0.125 NS	0.883
S.D.	7.42	13.49	10.50	W	4864.00	42	115.81
Post-test Mean	56.46	53.53	44.60	B	1146.13	2	573.06	5.58 *	0.007
SD	6.86	13.29	9.17	W	4313.06	42	102.69
Adjusted Post-test Mean	56.14	52.84	45.60	B	867.32	2	433.66	58.73 *	0.000
				W	302.71	41	7.38
HIIT		C.E.T.		C.G.		Mean Difference		Significance
56.14		52.84		-		3.30 *		0.002
56.14		-		45.60		10.54 *		0.000
-		52.84		45.60		7.24 *		0.000

. Table 1 shows the mean, S.D., and t-ratio score of the subject’s cardiovascular endurance between different training groups. As expected, both the training groups illustrate positive results with a t-ratio of 11.88 for HIIT and 14.58 for C.E.T., with 0.05 significant levels. In the control group, the result indicates no significant differences in mean scores of pre and post-tests and eventually in t-ratio. Further, ANCOVA was performed to find the significant difference among the mean scores of HIIT, C.E.T., and control groups on cardiovascular endurance.

Besides the ANCOVA as illustrated above, it is a clear picture of the relationship between different training groups and control groups in pre and post-test through the descriptive statistics and the ‘F’ value. The pre-test mean scores of HIIT, C.E.T., and control groups are 44.93, 45.33, and 43.46, with the SD of 7.42, 13.49, and 10.50, respectively, with calculated F- values 0.125 and p-value of 0.883 ≤ 0.05. Hence, no significant difference was seen between the control group and experimental groups. Additionally, the Table 1 display the significance of the differences between the paired means of HIIT.C.E.T. and Control groups by the post hoc test. As expected, the adjusted mean score of C.E.T. (52.84) group has outstripped the adjusted mean score of the control group (45.60) significantly. Consequently, from the result of the statistical analysis, it can be found that the HIIT group had a positive and higher impact on the cardiovascular endurance of the participant after 12 weeks of the training programme compared to C.E.T. and control group.

The data obtained from the analysis of paired t-test, pre-test and post-test means of HIIT, C.E.T., and control groups on muscular endurance have been detailed in

Table 2. The descriptive statistics, paired t-test, analysis of co-variance (ANCOVA), Scheffe’s post-hoc test for paired mean difference on muscular endurance of HIIT, C.E.T., and control groups (* Significant; ^NS Not Significant).

Traning Groups	Pre-Test			Post-Test			t-Ratio		Significance
	Mean		SD	Mean		SD
HIIT	34.80		6.18	40.46		4.61	10.00 *		0.000
C.E.T.	34.46		5.97	41.20		5.59	14.55 *		0.000
C.G.	33.13		4.54	33.66		5.06	1.65 NS		0.120
Groups	HIIT	CET	C.G.	SOV	Sum of Squares	df	Mean Square	F-Value	Significance
Pre-test Mean	34.80	34.46	33.13	B	23.33	2	11.66	0.37 NS	0.693
S.D.	6.18	5.97	4.54	W	1325.86	42	31.56
Post-test Mean	40.46	41.20	33.66	B	517.64	2	258.82	9.92 *	0.000
SD	4.61	5.59	5.06	W	1095.46	42	26.08
Adjusted Post-test Mean	39.89	40.91	34.52	B	347.29	2	173.64	65.33 *	0.000
				W	108.92	41	2.65
HIIT		C.E.T.		C.G.		Mean Difference		Significance
39.89		40.91		-		1.02 NS		0.094
39.89		-		34.52		5.37 *		0.000
-		40.91		34.52		6.39 *		0.000

. Table 2 shows the mean, S.D., and t-ratio of the subject’s muscular endurance score between different training groups. For example, the high-intensity interval training group had a mean score of 34.80 and 40.46, with an S.D. of 6.18 and 4.61 for pre and post-test, respectively. In the control group, the table shows no significant differences in mean scores of pre and post-tests and, eventually, in t-ratio.

The ANCOVA, Table 2, illustrated a clear picture of the relationship between different training groups and control groups in pre and post-test through the descriptive statistics and the ‘F’ value. The pre-test mean scores of HIIT, C.E.T., and control groups are 34.80, 34.46 and 33.13, with the SD of 6.18, 5.97 and 4.54, respectively, with calculated F-value 0.37 and p-value of 0.693 ≤ 0.05. Hence, no significant difference was seen between the control and experimental groups. In Table 2, it also displays the differences between the paired means of HIIT, C.E.T., and control groups by the post hoc test. Although the post hoc test displayed insignificant results between HIIT (39.89) and C.E.T. (40.91) groups, the mean difference found is 1.02 on the muscular endurance test. Therefore, it was expected to have significant changes. However, based on the studies to date, the nature of the variables says that 12 weeks of training is too short to bring changes.

The data obtained from the analysis of paired t-test, pre-test and post-test means of HIIT, C.E.T., and control groups on flexibility have been detailed in

Table 3. The descriptive statistics, paired t-test and analysis of co-variance (ANCOVA) on flexibility of HIIT, C.E.T., and control groups (* Significant; ^NS Not Significant).

Traning Groups	Pre-Test			Post-Test			t-Ratio		Significance
	Mean		SD	Mean		SD
HIIT	10.92		1.45	11.89		1.65	5.07 *		0.000
C.E.T.	10.28		2.22	11.07		2.20	6.71 *		0.000
C.G.	10.99		2.37	10.10		3.25	1.50 NS		0.153
Groups	HIIT	CET	C.G.	SOV	Sum of Squares	df	Mean Square	F-Value	Significance
Pre-test Mean	10.92	10.28	10.99	B	4.65	2	2.32	0.55 NS	0.581
S.D.	1.45	2.22	2.37	W	177.86	42	4.23
Post-test Mean	11.89	11.07	10.10	B	24.17	2	12.09	1.98 NS	0.149
SD	1.65	2.20	3.25	W	255.23	42	6.07
Adjusted Post-test Mean	11.70	11.51	9.84	B	31.24	2	15.62	7.62 *	0.02
				W	108.92	41	2.65

. ANCOVA was performed to find the significant difference among the mean scores of HIIT, C.E.T., and control groups on flexibility, as described in Table 3.

In Figure 1 the mean difference of pre-test, post-test and adjusted post-test of HIIT, C.E.T. and control group on total cholesterol is graphically displayed.

Figure 2 shows the mean difference of pre-test, post-test, and adjusted post-test of HIIT, C.E.T., and control group on triglyceride.

In Figure 3 shows the mean difference of pre-test, post-test, and adjusted post-test of HIIT, C.E.T., and control group on hemoglobin is graphically displayed.

Teenage children in China are most certainly confined to the classroom and are only rarely offered a physical training period, where 30–35 children will be given two or three balls and are made to play, which seems to be discouraging to the less fit children who merely withdraw themselves from further participation. Structured training programs were never introduced to teenagers until now. The literature review reveals that in the area of teenage children, the intervention program of HIIT and C.E.T. is limited and it is debated which training is better for children. So, the study was designed to assess the effect of the different endurance training programmes on selected health-related physical fitness, biochemical, and hematological variables in teenage boys. Especially taking consideration for the study are teenage boys aged 18–19 years, who are at a very peak age of changes and development physically, physiologically, and in cognitive functioning. Inculcation of physical activity and exercise during development add up to advantages. The present study illustrates that 12 weeks of HIIT and C.E.T. protocol have significant changes in VO₂, muscular endurance, flexibility, T.C., T.G., HDL, LDL, VLDL, H.G.B., R.B.C., and WBC. However, no changes were noticed in the control group.

13. Discussion

Discussion of Hypothesis 1: Teenage boys involved in HIIT will enhance HRPF variables- cardiovascular endurance, muscular endurance, and flexibility. The results of the findings of pre and post-test validate the hypothesis that teenagers who performed HIIT have improved cardiovascular endurance, muscular endurance, and flexibility. As significant differences were noticed in the variables, the research hypothesis was thus accepted.

Discussion of Hypothesis 2: It was also assumed that teenage boys involved in C.E.T. would significantly improve after 12 weeks of training on HRPF variables, cardiovascular endurance, muscular endurance, and flexibility. The study’s pre to post-test results showed significant changes in all the variables of HRPF following C.E.T. training. As significant differences were found in all the variables, the research hypothesis was thus accepted.

Discussion of Hypothesis 3: Biochemical variables such as T.C., T.G., HDL, LDL, and VLDL, would significantly change after 12 weeks of HIIT in teenage boys. The HIIT program for teenage boys resulted in an overall improvement in all the biochemical variables where all the variables showed significant differences. As a significant difference is noticed, the research hypothesis was thus accepted.

Discussion of Hypothesis 4: Significant changes in biochemical variables such as T.C., T.G. HDL, LDL, and VLDL, were predicted in teenage boys due to 12 weeks of C.E.T. programme. The results of the findings validate the hypothesis that teenage boys engaging in C.E.T. have significant improvement in biochemical variables. As significant differences were noticed in the variables, the research hypothesis was thus accepted.

Discussion of Hypothesis 5: Due to 12 weeks of HIIT programme, there would be significant changes in selected hematological variables such as hemoglobin, R.B.C., and the WBC of teenage boys. The HIIT effect on hematological variables resulted in a positive outcome in teenage boys. As significant differences were noticed in the variables, the research hypothesis was thus accepted.

Discussion of Hypothesis 6: There would be significant changes in selected hematological variables such as ae moglobin, R.B.C., and the WBC of teenage boys due to 12 weeks of C.E.T. programme. The results of the findings of pre and post-test validate the hypothesis that teenage boys in C.E.T. have an improved positive effect on blood variables- R.B.C., WBC, and hemoglobin. As significant differences were noticed in the variables, the research hypothesis was thus accepted.

Discussion of Hypothesis 7: There would be a significant difference between the training effects of HIIT and C.E.T. on health-related physical fitness, biochemical, and hematological parameters of teenage boys. The results of the findings of pre and post-test did not show any significant difference between the two training groups HIIT and C.E.T. on the variables, except for cardiovascular endurance, which tremendously improved in HIIT compared to C.E.T. As significant differences were not seen in the variables, the research hypothesis was thus rejected.

14. Conclusions

Physical exercise and different training interventions have been integral to motor development and designed to improve posture, physical development, general fitness, health, fun, and recreation. It also allows the demonstration of competence and increases social connectedness. Participation in exercise and activity proves to be beneficial for teenage boys as it helps increase and smooth motor acquisition of movements. Twelve weeks of HIIT and C.E.T. significantly improved selected HRPF variables (cardiovascular endurance, muscular endurance, and flexibility) with no significant difference in the control group. HIIT proves superior in enhancing cardiovascular endurance to C.E.T. while muscular endurance and flexibility did not show significance between both training groups. The positive influence was also seen in biochemical variables—T.C., T.G., HDL, and LDL in both HIIT and C.E.T. groups, while no difference was seen in the control group.

Further, the result revealed that total cholesterol, triglyceride, and high-density lipoprotein had a better outcome from HIIT protocol than C.E.T., but low-density lipoprotein and very-low-density lipoprotein were just vice-versa. In terms of hematological variables, significant improvement was seen following both the training programme, while there was no significant difference in the control group on hemoglobin, red blood cells, and white blood cells. It was also seen that the effect of HIIT on hemoglobin and white blood cells is more effective than C.E.T., although both showed significant improvement. Thus, HIIT and C.E.T. both elicit improvement in overall variables. Therefore, HIIT proves to be more effective in improving teenage boys’ health and indicated this study has improved most of the indicators.