THE EFFECTS OF AN 8 – WEEK HIGH INTENSITY INTERVAL TRAINING PROGRAMME ON THE CARDIOVASCULAR AND RESPIRATORY PARAMETERS OF SELECTED STUDENTS IN THE UNIVERSITY OF BENIN

CHAPTER ONE

INTRODUCTION

Background to the Study

There is a natural ability in humans to adapt to stress when faced with challenging physical activities. As an individual engage in movement/exertion, the body responds through a series of functional changes involving the physiological systems of the body and there is an activation of the musculoskeletal system. The individual’s circulatory and respiratory systems on their own part provides the body with the ability to perform these movements for an extended period of time.

Involvement in physical training and sports several times a week causes the physiological system within the individual’s body to undergo specific adaptation thus leading to an increase in the ability and efficiency of the body. The magnitude of these changes are greatly determined by the load used in the training, the intensity and training duration. Individuals achieve increased fitness when the exercise stress is greater than the minimum intensity level which the body is used to (Brooks, Fahey & Baldwin, 2005). Consistent physical training results in adaptation which involves relatively permanent changes in the functional and structural capabilities of the bodies of individuals engaged in exercise or training resulting in an improvement in their performance of tasks. The human body responds to exercise through a number of changes brought about in its physiological systems. Exercise and training affects the body system for the adaptation and better performance of the individual in all aspects of life.

Regular physical exercise affects the body systems positively for improved performance of the individual and also for better adaptation. Variables affected by physical exercise participation includes body mass index (BMI), heart rate, blood pressure (systolic and diastolic), VO₂ max and vital capacity. Exercise has been shown to improve stroke volume, heart rate, muscle hypertrophy which themselves are determinants of cardiac output (Hawkins, 2007).  This leads to an increase in the volume of blood circulated around the body during exercise, increase in the amount of nutrients, oxygen and other materials sent to the working muscles and also increases the speed of the waste removal process. While the benefits of exercise in improving the physical fitness level of individuals have been established by authorities all over the globe, there is however a major challenge in achieving this physical fitness through participation in regular structured physical activities in the general population today which is inadequate time for exercising

Also, the increased competitiveness and desire to win in modern sports has made it imperative for sport and health professionals to seek for ways of achieving increased adaptation, fitness and sports excellence both among athletes and the general population. This has led individuals to employ diverse training methods in achieving this desired success level. Among these different training methods is High intensity interval training.

High intensity interval training programme addresses the problem of time constraint which hinders people from engaging in training and fitness programmes which would help them in achieving fitness. It reduces the time required to exercise in comparison to low intensity programmes. High intensity interval training (HIIT), a form of aerobic training, has been widely used in sports to develop physical fitness and improve health and sports performance. It is a method of training characterised by brief intermittent bursts of vigorous activity which is interspersed by periods of rest or low intensity exercise. Continuous moderate-intensity aerobic exercise has traditionally been shown to generate improvements in some cardiometabolic risk factors (fasting insulin, glucose, systolic and diastolic blood pressure, and lipid profile) and aerobic capacity (VO₂max) in obese youth. High-intensity interval training (HIIT) has substantially increased in popularity over the last years. HIIT involves repeated bouts of high intensity efforts that range from 5 seconds to several minutes followed by recovery periods of varying lengths of time.

Billat (2001) points out that as early as 1912 Hannes Kolehmainen, famous Finish Olympic long-distance runner employed interval training in his workouts in preparation for the 1912 Olympics. As the knowledge of HIIT increased, exercise scientists demonstrated that this type of exercise not only provides performance benefits for athletes and improves the health of recreational exercisers, but it may also be a suitable alternative to endurance training, or continuous aerobic exercise. To improve cardiovascular fitness the belief has always been to increase the volume of exercise, whether it’s longer runs, bike rides, or extended time on an aerobic machine (e.g. stairstepper, elliptical, cycle, treadmill).

The main idea behind High intensity interval training is to allow for completion of maximal work load in a session by separating the work done in rest intervals (Kemi & Wisloff, 2010). This is to allow the physiological systems to get overloaded with exercise intensities greater than those achieved during a progressive maximal aerobic capacity test (Stuckey, Tordi, Mourot, Gurr, Rakobowchuk, Millar, Toth, Macdonald & Kamath, 2011).

Literature suggests that HIIT stimulates physiological remodeling similar to moderate intensity continuous training, despite the considerable shorter time commitment and reduced exercise volume (Gibala & McGee, 2008). Outcomes of this nature of exercise are of significance due to the fact that ‘lack of time’ is usually claimed as a barrier to regular exercise participation (Stutts, 2002; Trost, Pate, Sallis, Freedsons, Taylor, Dowda & Sirard, 2002; Kimm, Glynn, McMahon, Voorhees, Striegel-Moore & Daniel, 2006). Prescribing HIIT consists of manipulating some of these variables (e.g. work interval intensity and duration, relief interval intensity and duration, exercise modality, number of repetitions, number of series, between series recovery duration, and intensity).

A wide range of terms have been used in describing different interval training protocols. This has led to a general lack of standardization in the literature and different acronyms. A new classification scheme in which the term “HIIT” is used to describe protocols with a target intensity between 80-100% of maximal heart rate and the training stimulus is “near maximal” while “sprint interval training” (SIT) be used for protocols that involve “all -out” or “supramaximal” efforts, involving target intensities that correspond to workloads greater than what is required to elicit maximal oxygen uptake or (VO₂ peak) (Weston, Wisloff & Coombes, 2014).

Sedentarism which is the lack of adequate physical activity is a risk factor for a lot of diseases, such as diabetes mellitus, obesity, cardiovascular diseases and hypertension. Sedentary behaviour comprises a number of activities that involve very low energy expenditure, such as sitting while at work or school, watching television, using a computer or playing video games, reading, sitting while socialising with friends or family and sitting in a car or other form of motorised transport (e.g. school bus).

Technological advances and modern lifestyle has contributed a great deal to the unprecedented increase in sedentary lifestyle in the population. Modern means of transportation has created a situation in which lots of people expend a far lesser amount of calories in walking and in other physical activities. Participating in exercise is important at any age, and people of all ages should be encouraged to participate in physical activities so that health risk factors/lifestyle diseases can be prevented.

Malina and Katzmarzyk (2006) emphasized the importance of daily fitness and physical activities in schools and the promotion of health among youths worldwide, and stressed that in doing so there will be an elimination of the development of risk factors for several adult diseases. Trost (2007) stated that schools have the opportunity to promote and emphasise the importance of regular physical activities, to reinforce the benefits associated with health and wellbeing and should build skills that support active lifestyles. Ogden (2006) supported the view that the reduction in physical activities has put student’s health at risk and that it can’t be justified by the education system. The increasing lack of fitness activities in and out of school is evident and the importance of reducing sedentary behaviours is of high importance

It is undeniable that the reduction of participation in sedentary behaviours has significant benefits and rewards associated with it, such as reduced risk of cardio-metabolic disease, obesity and diabetes. Castelli, Hillman, Buck and Erwin (2007) agreed that there were many benefits of physical activities, and stated one of the many benefits of participating in physical activities was the potential it had to limit the frequency of risk factors related to cardiovascular disease in later life. Recent research has shown an increase in sedentary behaviour. This inactivity crisis is prevalent in school-aged students. Tremblay, LeBlanc, Kho, Saunders, Larouche, Colley, Goldfield and Gorber (2011) documented that ‘only 7% of children and youth aged 6-19 years participate in at least 60 minutes of moderate-to vigorous intensity physical activity per day’. For students who choose a sedentary lifestyle, increases in physical activities are associated with many benefits that will prevent some or all of the above health problems that are caused by inactivity.

Statement of the Problem

Regardless of the fact that physical inactivity is associated with increased risk of many diseases such as cardiovascular diseases, diabetes and other risk factors, participation in structured exercises by the general population remains low (Haskell, Lee, Pate, Powell, Blair, Franklin, Macera, Heath, Thompson & Bauman, 2007). The American College of Sports Medicine (2006) recommends that a minimum of 30 minutes of participation in moderate-intensity exercise on most days of the week helps to achieve health benefits. However, all over the world one major reason that people have given for their non-participation in exercise is lack of time (Nybo, Sundstrup, Jakobsen, Mohr, Hornstrup & Simonsen, 2010). Consequently, Coaches, Human kinetics teachers and other sports and health professionals have continued to seek structured exercise programmes of shorter duration which can also achieve the same desired purpose of fitness and physiological adaptation.

High intensity interval training is an exercise programme which last a very short duration and is done less frequently. Hence, it has become imperative to ascertain if and to what extent high intensity interval training would be able to cause physiological adaptation in the cardiovascular variables (heart rate, VO₂ max and blood pressure e.t.c) and also on the vital capacity of individuals.

Research Questions

The following research questions guided the study

1. Will there be any difference in the heart rate of the participants prior to and following an 8-week high intensity interval training programme?
2. Will there be any difference in the systolic blood pressure of the participants prior to and following an 8-week high intensity interval training programme?
3. Will there be any difference in the diastolic blood pressure of the participants prior to and following an 8-week high intensity interval training programme?
4. Will there be any difference in the vital capacity of the participants prior to and following an 8-week high intensity interval training programme?
5. Will there be any difference in the VO₂max of the participants prior to and following an 8-week high intensity interval training programme?

Research Hypotheses

The following hypotheses were formulated and tested at 0.05 level of significance.

1. There is no significant difference in the heart rate of the participants prior to and following an 8-week high intensity interval training programme.
2. There is no significant difference in the systolic blood pressure of the participants prior to and following an 8-week high intensity interval training programme.
3. There is no significant difference in the diastolic blood pressure of the participants prior to and following an 8-week high intensity interval training programme.
4. There is no significant difference in the vital capacity of the participants prior to and following an 8-week high intensity interval training programme.
5. There is no significant difference in the VO₂max of the participants prior to and following an 8-week high intensity interval training programme.

Purpose of the Study                                       

The purpose of this study was to ascertain the effects of an 8 – week high intensity interval training programme on the cardiovascular and respiratory parameters of selected students in the University of Benin.

Specifically, the objectives are:

• To ascertain the possible difference in the Heart rate of participants prior to and following 8-weeks High intensity interval training.
• To ascertain the possible difference in the systolic blood pressure of participants prior to and following 8-weeks High intensity interval training.

• To ascertain the possible difference in the diastolic blood pressure of participants prior to and following 8-weeks High intensity interval training.
• To ascertain the possible difference in the Vital capacity of participants prior to and following 8-weeks High intensity interval training.
• To ascertain the possible difference in the VO₂max of participants prior to and following 8-weeks High intensity interval training.

Significance of the Study

• Findings from this study provides ample empirical evidence about the interplay of cardiorespiratory parameters in response to exercise training in the University of Benin.
• Also, this study will enhance the knowledge of Sport administrators, trainers, coaches and teachers at the different levels of educational and sporting institutions and equip them with methods of enhancing the performance of athletes and developing amateurs into high achieving professionals.
• The result of this research is of great importance to sedentary individuals and provides a means of developing and maintaining physical fitness and improving performance in a wide variety of physical activities.
• The result of this study adds to the existing body of knowledge and serve as a basis for future researchers to draw inferences from.

Scope and Delimitation of the Study

This study covered all undergraduate students in the University of Benin, Benin City registered in the 2017/2018 academic session. It was delimited to the determination of physiological adaptation in the blood pressure, heart rate, vital capacity and VO₂max of students following high intensity interval training.

Limitation of the Study

The major limitation that the researcher encountered in the course of this study is lack of cooperation or apathy by some students who were part of the study. Also, training coincided with some students’ reading schedule or time allotted for other personal activities.

Operational Definition of Terms

In this study, high intensity interval training (HIIT) is defined as a type of training that is characterized by relatively short bursts of vigorous activity, interspersed by periods of rest or low-intensity exercise for recovery.

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