‘Research is formalized curiosity. It is poking and prying with a purpose’ (Hurston, N.Z. 1942)
A quote which has a vast amount of relevance to the task at hand, where research will be located, evaluated and discussed in order to find the benefits and negatives of each paper. My aim during this task is to locate three academic research papers using the EPSCO database for papers that will discuss the health benefits of high-intensity training vs moderate intensity training of individuals who are overweight or obese. A summary of what the aim for each paper is, and what methods are used to discover this will be completed, alongside a constructed evaluation that will establish what the strengths and weaknesses of each paper are.
The three papers that I will be evaluating are:
Martins, C. Et Al. (2016) ‘High-Intensity Interval Training and Isocaloric Moderate –Intensity Continuous Training Results in Similar Improvements in Body Composition and Fitness in Obese Individuals.’ International Journal of Sports Nutrition. Vol 26. Pg. 197-204.
Jurio-Iriarte, B. & Maldonado-Martin, S. (2018) ‘Effects of Different Exercise Training Programs on Cardiorespiratory Fitness in Overweight/Obese Adults with Hypertension: A Pilot Study’. Health Promotion Practice. Pg. 1-11.
Fisher, G. Et Al. (2015) ‘High Intensity intervals vs. Moderate intensity Training for Improving Cardiometabolic Health in Overweight or Obese Males: A Randomized Controlled Trail’ HIIT vs. MIT for Improving Cardiometabolic Health in Overweight Males. Pg. 1-15.
The objective for the first study is to determine the effects of high-intensity intermittent training (HIIT), moderate-intensity training (MICT) and a short duration HIIT (1/2 HIIT) has on the body composition, body weight, cardiovascular fitness, resting metabolism rate (RMR), respiratory exchange rate (RER) on sedentary obese individuals. While the goal for the second study is, to compare high-intensity training vs. moderate-intensity training on cardiorespiratory fitness in overweight or obese young adults, who are diagnosed with hypertension. The third and final study, aims to compare the effects of high-intensity training (HIIT) vs. continuous moderate intensity training for improving cardiovascular fitness, body composition, insulin sensitivity, blood pressure and blood lipids in sedentary overweight or obese young men.
Study 1 involved a total of 46 sedentary obese individuals, 30 females and 16 males with an age range of 25-44 and a weight between 84kg – 112kg with a BMI of 30.4-36.2. They classified ‘sedentary’ as individuals who do not engage in strenuous work or in regular brisk physical activity more than once a week, or light exercise for more than 60 minutes per week.
Study 2, had a total of 70 individuals participating within the study who were all also classed as sedentary and overweight or obese. To classify as overweight, the participants had to have a BMI of 25 or above, and to classify as obese, a BMI of 30 or above was required. They also had to be diagnosed with stage 1 or 2 of hypertension. However, within this study, to be sedentary the participants had to not comply with the ‘Global Recommendation on Physical Health’ which states that individuals participating should not complete more than 150 minutes of aerobic activity per week or 75 minutes of vigorous activity per week in order to classify as part of the study. (World Health Organisation. 2018)
While Study 3 had an overall number of 28 participants who were all also classed as overweight or obese, with BMI’s between 25-35 and aged between 17-22 years. The requirement for this study was that the participants didn’t complete more than 30 minutes of structured activity per week.
There are a number of differences within the requirements of the participants within each of the trails, but one requirement was that the participants for each of the trails must be sedentary, which ranged from 150 minutes per week in study 2, to 30 minutes per week in study 3. According to the Definitions of Sedentary in Physical Activity intervention Trails, the most frequent suggestion was that sedentary was 60 minutes of exercise over a space of a week (Bennett, J. 2006). This suggests that study 2, which allows up to 150 minutes would have a more physically active group of individuals than the other trails, which could affect the overall outcomes.
Another factor that could affect the outcome of the results is the number of participants used in each trail, otherwise known as the ‘sample size’. If the sample size was larger, the likelihood of having a more reliable result would be greater. This is due to a small sample size being at risk of including ‘unrepresentative numbers of extreme values’ but if the sample size was bigger the ‘distribution narrows towards the mean value’ (Springate, S.D. 2012). so, the study with the larger amount of participants is more likely to have the more reliable results.
The method for the Study 1 was to allocate participants to either a HIIT, MICT or ½ HIIT which took place 3 times per week, for 12 weeks using a Monark Cycle ergometer. Before the trail begun measurements were taken, as well as a V02 Max test begin taken before the trail, at week 4 and 8 and then again after the trail was complete. This was to calculate the prescribed exercise duration to meet the energy deficit for each participant. HIIT participants had 8 seconds of sprinting at 85-90% HRM and then 12 seconds of recovery. This was repeated until they reached an energy deficit of 250kcals. The ½ HIIT followed the same procedure, except they had to reach an energy deficit of 125kcals. While the MICT had to continuously exercise at 70% of HRM until 250kcal deficit was reached.
Study 2 used a similar method to study 1, where they took measurements at different times throughout the trail at week 8, 12 and 16. This trial lasted a total of 16 weeks, with the participants completing two 45 minute sessions a week. The HIIT had to exercise at 76-95% HRM while the MICT had to exercise at 50-75% HRM. This is one of the major differences between study 1 and 2, the HRM for MICT for study 1 is continuously 70% throughout, whereas study 2 has given the participants a wider option between 50-75% which could affect the outcomes, as some participants may exercise at 75% where others may choose to stay at 50%. The trail used a bike and a treadmill in order to prevent partakers from suffering with joint injuries.
Study 3 lasted for a total of 6 weeks with participants being tested pre-trail and post-trail. The HIIT performed for a total of 20 minutes, cycling at 15% of HRM for 4 minutes, and then 30 seconds at 85% of HRM which was repeated 4 times and ending with 15% of HRM for 2 minutes to cool down. This was performed 3 times per week.The MICT had to complete 45-60 minutes of continuous cycling at 55-65% of V02 peak. This was performed 5 days a week for 6 weeks.
There are strengths and weakness in all three studies, however, it is obvious after taking time to research and evaluate each study, which one has conducted the most time and effort.
Study 1, this trial lasted a total of 12 weeks with the participants being tested a number of times throughout the trail in order to ensure all measurements, such as the HRM they were exercising at was still the same. The weakness was that the trial didn’t include as many participants as the others, and was using a small number of people to complete three different tests which made their sample sizes even smaller.
Study 2, this was the trial with the highest amount of participants with a total of 70 people involved. They also tested each participant throughout the trail to adjust measurements accordingly. They also used two different equipment’s for the participants to use, the bike on one day and the treadmill on the other. This was to avoid ‘osteoarticular impact’ which none of the other studies spoke about. The weakness was that the heart rate maximum that the participants were told to exercise at had a wider range than the other studies. However, in person opinion I believe this was the strongest trial.
Study 3, I believe this was the weakest out of all three due to a few reasons. The first is that it had the lowest number of participants, and the second is that the study only lasted for 6 weeks, and also that the participants was not tested throughout the trail, just at the beginning and at the end, unlike the others studies.
“Ethics refers to a system of principles which can critically change previous considerations about choices and actions. It is said that ethics is the branch of philosophy which deals with the dynamics of decision making concerning what is right and wrong” (Fouka, G. & Mantzorou, M. 2011)
There are many issues that can become apparent when completing a research study, particularly when involving participants. The first and most important ethical consideration is the consent of all participants. All volunteers must understand the nature of the trail, and all the risks that involved. (Manton, A. 2014). Another issue that is of great importance is respecting the dignity and anonymity of each participant which has much relevance to the three studies I have researched. All three studies involve participants who have health issues, either obesity, being overweight, a high BMI or Hypertension. Not all individuals would want the world to know who they are, or that they have these health conditions. So it is important that the researchers who are conducting the study pay extra attention to ensuring that each participant stays anonymous and their dignity is upheld throughout the trail, and that no links can be made to the identity of each participant through personal responses throughout the trail. Also, the ability for the researchers to release certain personal information about each participant within the reports, such as, their BMI, the lack of activity they complete or their weight, must be discussed and agreed too before the trail begins. (Fouka, G. & Mantzorou, M. 2011)
Another ethical consideration that all researchers must adhere too is the safety of all participants, prior, during and after the trail. As all three studies are exercise based, and all three required subjects who are inactive or aren’t classed as physically active. That within itself could be a risk for injury due to each participant not being used to completing exercise of this nature as it runs a risk of orthopaedic injury (ACSM. 2006). Study 2 was the only ones that mentioned the risk of participants using the same equipment to complete their exercise, suggesting that it runs a risk for ‘osteoarticular impact’ so they used two different types of equipment in an attempt to avoid this. However, the other two studies didn’t adhere to the ethical considerations of the health and safety of their participants due to the research procedures used being a potential issue for the individuals involved with no suggestions on how to evade it.
When conducting a research study, there are two different approaches that can be taken depending on which option is the most appropriate. These are: A Cross-sectional study or an Interventional Study.
A Cross-sectional research question: Is there a difference between overweight and underweight individuals when it comes to the benefits of HIIT vs. MICT training?
To conduct this study, participants who are overweight and underweight would be randomly selected and would fully understand the study at hand before asking for their consent. All testing would be done prior to the trail, which would collect data for: weight, BMI, body composition, RER, RMR and blood pressure. As well as a VO2 Max test. The participants from the two groups would then be randomly assigned either HIIT or MICT. The participants who are assigned to the HIIT exercise, would complete 2 minutes of high-intensity exercise at 80% of their HRM which would be distinguished from a VO2 Max test. They would then have 2 minutes rest, at 15% of their HRM. This would be completed 5 times, totalling 20 minutes of exercise. This would be done twice a week for 10 weeks.The subject who are assigned to the MICT exercise, would complete 40 minutes of exercise at a 45% HRM. This would be completed 3 times a week, over 10 weeks.Subjects would then be retested to compare any difference between the weight categories, and the HIIT or MICT categories.
Another way a study can be completed, is through an Interventional question:
Will the development of fitness using HIIT vs. MICT help improve the overall health of overweight individuals?
To complete this study, overweight participants would be randomly selected and be made aware of what the study will involve, before being asked for consent to participate. Before the trail begins, subjects will be tested for body composition, RER, RMR, blood pressure, weight, BMI and will also complete a VO2 Max test in order to find what their heart rate maximum is. The subjects will then be randomly assigned to either the HIIT or MICT exercise. The HIIT subjects will complete 2 minutes of exercise at 80% of their HRM and then 2 minutes of exercise at 15% of HRM. This will be repeated 5 times, totally 20 minutes. This will be completed twice a week for 10 weeks.The MICT subjects will complete 40 minutes of exercise at 45% HRM. They will do this 3 times a week, for 10 weeks. All subjects will then be retested and comparisons between HIIT and MICT will then be made.
Within this task, I will present data that demonstrations if there are any links to an individual’s lung function and if the variances in height creates any significant differences.
Table 1 – Descriptive Statistics: Height, Forced Vital Capacity, Forced Expired Volume in 1 second, Peak flow and Forced Expired Ratio.
Mean Standard Deviation Range
Height (cm) 170.8235 9.15311 35
FVC (L) 3.9941 0.64341 2.63
FEV1 (L) 3.7218 0.66053 2.41
FER (L) 0.9065 0.07533 0.17
Peak Flow (L) 507.8824 95.583 318
Table 2 – Test for Normality (Shapiro-Wilk):
Height, Forced Vital Capacity, Forced Expired Volume in 1 second, Forced Expired Ratio, Peak Flow.
Statistics DF Sig.
Height 0.935 17 0.259
FVC 0.975 17 0.903
FEV1 0.976 17 0.91
FER 0.733 17 0
Peak Flow 0.909 17 0.096
Within the Shapiro-Wilk test that was conducted to determine the p-value: It was discovered that the p-value was larger than 0.05 which proves a normal distribution between the data that was collected.
center28591600Correlation between Height and FVC
The Graph shows a positive correlation between Height and FVC: R value – 0.658 and P value – 0.003
The difference of Forced Vital Capacity with Males and Females
The mean of the Forced Vital Capacity is 0.32L. However, the P-value is 0.247 meaning that the outcome could come about by chance.
The Difference in height between Males and Females
The mean height difference between the Males and the Females is 5cm. However, The P value is 0.288 which means the results could come about by chance.
Total Word Count: 2524
Armstrong, L. Et al (2006) ‘Guidelines for Exercise Testing and Prescription, Seventh Edition’ American College of Sports Medicine.
Bennett, J.A. (2006) ‘Definitions of Sedentary in physical activity intervention trails: A summary of the literature.’ Journal of Aging and Physical activity. Volume 4. Ph. 456-477.
Fisher, G. Et Al. (2015) ‘High Intensity intervals vs. Moderate intensity Training for Improving Cardiometabolic Health in Overweight or Obese Males: A Randomized Controlled Trail’ HIIT Vs. MIT for Improving Cardiometabolic Health in Overweight Males. Pg. 1-15.
Fouka, G. ; Mantorou, M. (2011) ‘What are the Major Ethical Issues in Conduction Research? Is there a conflict between the Research Ethics and the Nature of Nursing’ Health and Science Journal. Volume 5. Issue 1. Pg. 1-12
Jensen, M. D. Et Al. (2014) ‘TOS guideline for the management of overweight and obesity in adults: A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines and The Obesity Society’. Journal of the American College of Cardiology.
Jurio-Iriarte, B. ; Maldonado-Martin, S. (2018) ‘Effects of Different Exercise Training Programs on Cardiorespiratory Fitness in Overweight/Obese Adults with Hypertension: A Pilot Study’. Health Promotion Practice. Pg. 1-11.
Manton, A. Et Al. (2014) ‘Ethical Considerations in Human Subject Research’ Journal of Emergency Nursing. Volume 40. Issue 1. Pg. 92-94.
Martin, C. Et Al. (2016) ‘High-intensity interval training and Isocaloric Moderate Intensity continuous training Results in Similar Improvements in body Composition and Fitness in Obese Individuals’ International Journal of Sports Nutrition and Exercise Metabolism. Vol. 26. Pg. 197-204
NHS (2018) ‘Healthy Weight’ Online Available at: https://www.nhs.uk/live-well/healthy-weight/
Springate, S.D. (2012) ‘the effects of a sample size and bias on the reliability of estimates of error: a comparative study of Dahlberg’s formula’ European Journal of Orthodontics. Volume 34. Issue 2. Pg. 158-163.
World Health Organisation. (2018) ‘Recommended levels of physical activity for adults aged 18-64 years’. Online Available at: http://www.who.int/dietphysicalactivity/factsheet_adults/en/