Relationship Between BMI & HRR After 4 Weeks of Aerobic Training

Overweight Clinical Trial

Official title:

Relationship Between Body Mass Index and Heart Rate Recovery Following 4 Weeks of Aerobic Training Among Young Physically Inactive Adults

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT02781402
• Other study ID #: U/SERC/82/2015
• Status: Completed
• Phase: N/A
• First received: May 13, 2016
• Last updated: March 21, 2018
• Start date: July 2016
• Est. completion date: November 2016

Study information

• Verified date: March 2018
• Source: Universiti Tunku Abdul Rahman
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

World Health Organization (WHO) defined body mass index (BMI) as the ratio of weight in kilograms to the square of the height in meters (kg/m2). BMI has been used widely to diagnose obesity as it is a simple method to be carried out and is also inexpensive. According to WHO, there were 1.9 billion overweight individuals in 2014 with the age of 18 years old or above. Of 1.9 billion overweight individuals, there were 600 million obese adults. The prevalence of cardiovascular disease is higher among the overweight and obese individuals compared to individuals with normal body mass index. This probably is due to altered cardiovascular autonomic regulation. The risk of getting cardiovascular diseases is also higher among physically inactive individuals. As much as 60% of American adults are not regularly active and 25% of them are not active at all. Obese and overweight individuals tend to be physically inactive and it has been shown that there is a negative relationship between BMI and heart rate recovery (HRR). HRR is defined as difference in heart rate between maximum exercise and 1 minute later during recovery period after stopping of exercise. HRR after exercise stress is due to withdrawal of sympathetic nervous system and the reactivation of parasympathetic nervous system. Parasympathetic nervous system is altered in obese individuals therefore leading to poor HRR after exercise. Aerobic training not only can reduce the body composition but also improves the autonomic cardiovascular control. There is limited literature support for any study which shows that potential of 4 weeks aerobic training can influence the heart rate recovery in sedentary healthy adults. Most of studies conducted were using minimum of 6 to 8 weeks of aerobic training. The potential of 4 weeks of aerobic training in improving the autonomic nervous system among sedentary adults is still unclear. Therefore, we hypothesized in our study that there will be effect of 4 weeks of aerobic training on vagal modulation.

Description:

Obesity is a complex health issue that results from various causes and contributing factors. Individual factors like genetics and behavior may contribute to overweight and obesity. Genetics played an important role in increasing hunger and food intake of individuals. A few examples of common diseases that are related to obesity are type-2 diabetes, stroke, coronary heart disease and some types of cancer. All these obesity related diseases may not be fully reversible even after weight loss . Body mass index (BMI) is used widely as a screening tool to assess overweight and obesity. Based on the World Health Organization (WHO) international classification of BMI, individuals are considered as obese if their BMI value is equal to 30 kg/m2 or higher and overweight if BMI is 25-29.9 kg/m2. A study was conducted in USA to find the prevalence of obesity among children and adults. Researchers attempted to predict the childhood obesity and analyse the obesity trend among adults in United States. The results of the study showed that the prevalence of obesity among children were 16.9% and adults were 34.9%. There were no obvious changes in prevalence of obesity among children and adults in between 2003-2012 in United States (1). It cannot be denied that there is a link between increasing rate of obesity and increasing medical spending. Medical spending for obese individuals was 42% higher compared to those with normal body weight (2). The researchers reported in their study that obesity was one of the factors that became an economic burden for both public and private payers. South East Asia and Western Pacific countries suffer from diseases associated with obesity such as cardiovascular diseases and diabetes. Malaysia is the country the highest rate of obesity in South East Asia (3). Studies have showed that autonomic nervous system is associated with obesity. In 2001, a study was conducted to identify the effect of weight loss on autonomic nervous system. The findings showed that the activity of parasympathetic nervous system increased with weight loss and cardiac vagal tone improved significantly after weight loss (4). Cardiac vagal tone is controlled mainly by parasympathetic nervous system and this helps to improve the heart rate recovery (HRR). There are two phase of heart rate recovery, fast and slow phase. The fast phase is due to cardiac parasympathetic reactivation while the slow phase is because of cardiac sympathetic withdrawal. If there is any disturbance of the autonomic nervous system then the HRR will slow down (5). Therefore, HRR can be used to assess the cardiac autonomic function and as a marker of cardiac vagal tone. Abnormal heart rate recovery after exercise stress can be considered as dysfunction of autonomic nervous system. It has been suggested in several studies that heart rate recovery after exercise stress is slower among obese individuals compared to BMI individuals. A study was conducted to identify the relationship between heart rate recovery and body mass index. The finding showed that there was a negative association between heart rate recovery and body mass index. 3.5% of 2443 individuals presented with delayed decrease heart rate recovery. The prevalence of decreased heart rate recovery was higher among overweight and obese groups (6). In another study similar findings were observed. Researchers concluded that obese individuals are more likely to have an impaired heart rate recovery during the recovery phase after exercise (7). Aerobic training improves the autonomic cardiovascular control. A study on 4 weeks of aerobic training was done to identify its effects on cardiac vagal tone. Authors reported that 4 weeks of treadmill aerobic training was able to improve the autonomic nervous system among pre-hypertension individuals (8). The aerobic training consisted of 30 minutes treadmill exercise at 65% of maximum oxygen consumption. Another study showed the similar results in which the autonomic nervous system was improved after 6 months of moderate intensity aerobic training (9). The aerobic training was carried out 1 hour each session with 2 sessions in one week for 6 months. The present systematic review shows that aerobic training has been proven to be effective in increasing the heart rate recovery among subjects with established heart disease (10). The effects of 4 weeks of aerobic training in improving the cardiac vagal tone among sedentary healthy adults are still unclear. Therefore, we aim to study the effects of 4 weeks of aerobic training on vagal modulation.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 25
• Est. completion date: November 2016
• Est. primary completion date: October 2016
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 18 Years to 25 Years

Eligibility

Inclusion Criteria:

1. Sedentary subjects

2. Age between 18 to 25 years old

3. Body mass index range = 18.50 - 24.9 kg/m² (normal) = 25 - 29.9 kg/m² (overweight)

Exclusion Criteria:

1. Subjects with cardiovascular disease

2. Subjects with musculoskeletal problem

3. Not willing to participate

Related Conditions & MeSH terms

• Overweight

Intervention

Procedure:
• 4 weeks of Aerobic Training
The duration of aerobic training was 40 minutes for each session and 3 days per week with the intensity of 75-80% of their maximum heart rate. The participants were needed to walk or jog on treadmill during the first 10 minutes at the intensity of 50-60% of maximal heart rate (HR max). The aerobic training was followed by 4 x 4 minutes intervals at 75-80% HR max. The participants were given 3 minutes active breaks in between the intervals in which they can either walk or jog at 50-60% of maximal heart rate.

Locations

Country	Name	City	State
n/a

Sponsors (1)

Lead Sponsor	Collaborator
Universiti Tunku Abdul Rahman

References & Publications (9)

Barbosa Lins TC, Valente LM, Sobral Filho DC, Barbosa e Silva O. Relation between heart rate recovery after exercise testing and body mass index. Rev Port Cardiol. 2015 Jan;34(1):27-33. doi: 10.1016/j.repc.2014.07.006. Epub 2015 Jan 8. English, Portuguese. — View Citation

Brinkworth GD, Noakes M, Buckley JD, Clifton PM. Weight loss improves heart rate recovery in overweight and obese men with features of the metabolic syndrome. Am Heart J. 2006 Oct;152(4):693.e1-6. — View Citation

Collier SR, Kanaley JA, Carhart R Jr, Frechette V, Tobin MM, Bennett N, Luckenbaugh AN, Fernhall B. Cardiac autonomic function and baroreflex changes following 4 weeks of resistance versus aerobic training in individuals with pre-hypertension. Acta Physiol (Oxf). 2009 Mar;195(3):339-48. doi: 10.1111/j.1748-1716.2008.01897.x. Epub 2008 Sep 4. — View Citation

Finkelstein EA, Trogdon JG, Cohen JW, Dietz W. Annual medical spending attributable to obesity: payer-and service-specific estimates. Health Aff (Millwood). 2009 Sep-Oct;28(5):w822-31. doi: 10.1377/hlthaff.28.5.w822. Epub 2009 Jul 27. — View Citation

Gondoni LA, Titon AM, Nibbio F, Augello G, Caetani G, Liuzzi A. Heart rate behavior during an exercise stress test in obese patients. Nutr Metab Cardiovasc Dis. 2009 Mar;19(3):170-6. doi: 10.1016/j.numecd.2008.07.001. Epub 2008 Sep 19. — View Citation

Gulli G, Cevese A, Cappelletto P, Gasparini G, Schena F. Moderate aerobic training improves autonomic cardiovascular control in older women. Clin Auton Res. 2003 Jun;13(3):196-202. — View Citation

Ogden CL, Carroll MD, Kit BK, Flegal KM. Prevalence of childhood and adult obesity in the United States, 2011-2012. JAMA. 2014 Feb 26;311(8):806-14. doi: 10.1001/jama.2014.732. — View Citation

Rissanen P, Franssila-Kallunki A, Rissanen A. Cardiac parasympathetic activity is increased by weight loss in healthy obese women. Obes Res. 2001 Oct;9(10):637-43. — View Citation

Snoek JA, van Berkel S, van Meeteren N, Backx FJ, Daanen HA. Effect of aerobic training on heart rate recovery in patients with established heart disease; a systematic review. PLoS One. 2013 Dec 18;8(12):e83907. doi: 10.1371/journal.pone.0083907. eCollection 2013. Review. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Change in Heart Rate Recovery	The participants were required to take part in the exercise testing before beginning the 4 weeks of aerobic training. Ebbeling submaximal treadmill (EbbTM) protocol was used during the exercise testing. Finger pulse oximeter was placed on the participants' finger. The particiapnts were required to warm up for 4 minutes by walking at the speed that maintains the heart rate within 50% to 70% of their maximum heart rate (HR max) without any inclination (0% grade). Following 4 minutes of warm up, the participants walked at the same speed for another 4 minutes at a grade of 5%. After cessation of exercise test, heart rate was immediately recorded from the pulse oximeter for 1 minute. The heart rate was measured during the passive recovery phase in which the participants were in supine position.	At baseline and After 4 weeks of aerobic training
Secondary	Change in Body Mass Index	BMI to be measure before and at end of 4 weeks of aerobic training to see any differences and impact of aerobic training on BMI.	At baseline and After 4 weeks of aerobic training