High-intensity Interval Training versus Traditional Exercise in Adults with Overweight and Obesity

| August 1, 2017

by Anthony Auriemma, MD, JD

Dr. Auriemma is from AMITA Health Bariatric and Weight Loss Center, Schaumburg, Illinois.

Column Editors:

Craig Primack, MD, FACP, FAAP

Medical Bariatrician/Certified Medical Obesity Specialist/ Co-Medical Director, Scottsdale Weight Loss Center PLLC, Scottsdale, Arizona

Wendy Scinta, MD, MS, FAAFP

Medical Director, Medical Weight Loss of NY, BOUNCE Program for Childhood Obesity, Fayetteville, New York; Clinical Assistant Professor of Family Medicine, Upstate Medical University, Syracuse, New York

This column is dedicated to providing information on the medical management of obesity, which includes nutrition, physical activity, behavioral modification, and medication management.

Bariatric Times. 2017;14(8): 12–15.

Funding: No funding was provided for this article.

Financial Disclosures: Dr. Auriemma reports no conflicts of interest relevant to the content of this article.

Abstract: High-intensity interval training, characterized by performing short bursts of maximum intensity exercise, often called “on” intervals, followed by performance of a brief low-intensity activity or “off” interval, has gained popularity worldwide. This form of physical activity has been proven to have similar health benefits as traditional exercise (e.g., moderate intensity continuous exercise), decreasing cardiovascular and metabolic risk factors, often in less time. However, studies have arrived at different conclusions regarding detailed physiologic measures experienced with HIIT. Here, the author presents available guidelines for physical activity in United States adults and discusses recent literature on high-intensity interval training in individuals with overweight and obesity so clinicians might better evaluate whether high-intensity interval training should be recommended in this patient population.

Keywords: exercise, physical activity, high-intensity interval training, obesity, metabolic syndrome

Introduction

In the era of the The Biggest Loser® and “boot camp” style exercise regimens, the idea of starting an exercise program has become intimidating for many patients. The popularity of this form of exercise is demonstrated by the rapid growth of national chains like Orange Theory® Fitness and CrossFit®. These programs comprise exercise routines referred to as high-intensity interval training (HIIT). HIIT, also called high-intensity intermittent exercise (HIIE) or sprint interval training (SIT), is a form of physical activity where one performs a short burst of high-intensity (or max intensity) exercise, often called “on” intervals, followed by a brief low-intensity activity or “off” intervals. HIIT has been shown to improve cardiovascular fitness in less time than conventional exercise.[1]

However, with the growing popularity of HIIT, clinicians might be wondering whether this form of exercise is safe and effective in the patient population with overweight or obesity, and might thus offer an alternative to traditional exercise.

Guidelines for Physical Activity in Adults

Professional organizations provide evidence-based recommendations for exercise in the adult population. Although the available guidelines do not include HIIT in particular, they do address the numerous health benefits of regular physical activity, such as lower risk of premature death, coronary heart disease, stroke, hypertension, type 2 diabetes mellitus (T2DM), and depression.

The Federal Physical Activity Guidelines,[2] released in 2008 by the United States Department of Health and Human Services briefly examines the relationship between physical activity and health, with a separate section discussing metabolic health. They state that lower rates of obesity-related comorbidities (e.g., type 2 diabetes mellitus [T2DM], high blood pressure), are seen with 120 to 150 minutes (2 hours to 2 hours and 30 minutes) per week of at least moderate-intensity aerobic activity. This is in line with its physical activity recommendations for general health benefits: 150 minutes per week of moderate intensity (e.g., brisk walking), 75 minutes of vigorous intensity (e.g., jogging), aerobic physical activity, or an equivalent combination.

With the looming risk of weight regain after weight loss achieved by any means (e.g., lifestyle modification, pharmacotherapy, surgery), it is crucial that every exercise regimen considers what is needed to maintain weight and prevent regain. The Federal Physical Activity Guidelines address this with their recommendation of a minimum of 150 to 300 minutes per week of moderate physical activity to provide weight stability and more than 300 minutes per week if the goal is to lose and maintain greater than five percent weight loss.

Studies further prove that exercise helps with weight maintenance. The National Weight Control Registry (NWCR), a longitudinal study established to examine characteristics of successful weight loss maintainers defined as “individuals who have intentionally lost at least 10 percent of their body weight and kept it off at least one year.” One characteristic found among maintainers is high levels of physical activity representing approximately 60 minutes per day of moderate-intensity activity, such as brisk walking. The most common activity recorded in the registry is walking (76% of participants) following by weight lifting (20%) cycling (20%), and aerobics (18%).[3]

Though published in 2008, the recommendations of The Federal Physical Activity Guidelines have been continually echoed by professional organizations and societies, many geared toward addressing the needs of individuals with overweight and obesity in particular. The 2013 American Heart Association (AHA)/American College of Cardiology (ACC)/The Obesity Society (TOS) guidelines for treating overweight and obesity[4] stated that strong evidence existed to support “a program of increased physical activity” be included in an effective high-intensity, on-site comprehensive-lifestyle intervention. Here, “increased physical activity” refers to aerobic exercise performed 150 minutes or more per week (equal to ≥ 30 minutes/day, most days of the week). Their recommendations for weight maintenance/prevention of weight regain are close to those The Federal Physical Activity Guidelines—approximately 200 to 300 minutes/week.

The American Association of Clinical Endocrinologist (AACE) and American College of Endocrinology (ACE) comprehensive clinical practice guidelines,[5] released in 2014 include lifestyle/behavioral therapy recommendations for treating patients with overweight and obesity. Again, an ultimate goal of 150 minutes or more per week of moderate exercise is recommended in this patient population.

In addition, they state that this exercise should be performed during 3 to 5 daily sessions per week. In addition, they recommended resistance training 2 to 3 times per week consisting of single-set exercises that use the major muscle groups in order to help promote fat loss while preserving fat-free mass.

Current Evidence on HIIT in Individuals With Overweight and Obesity

Though not included in the existing physical activity guidelines, HIIT is increasingly being studied, and researchers are arriving at varying conclusions. Some research has proven the effectiveness of HIIT in individuals with overweight and obesity, pointing to improvements in cardiovascular and metabolic risk factors.[6,7]

One argument for the employment of HIIT is time effectiveness. Growing evidence also shows that through HIIT, individuals might achieve the benefits of traditional continuous exercise training (e.g., increased cardiorespiratory fitness and insulin sensitivity) in 50 to 60 percent of the training time.[1,7,8] However, some researchers, some in the same groups that confirmed the time-efectiveness of HIIT, found that HIIT is lacking in key physiologic effects of exercise, such as the thermogenic response to β-adrenergic stimulation, maximal cardiac output, and fat distribution, a conclusion that tests the time-saving attractiveness of this alternate exercise form.[9]

In a recent study by Keating et al,[1] researchers compared low-intensity continuous exercise to HIIT training. Thirty-eight adults who were determined to be inactive (exercising <3 days/week) and have overweight (BMI 25kg/m2 to 29.9kg/m2) were randomized to one of three groups: HIIT, continuous exercise training (CONT), or placebo group (PLA), for 12 weeks. The HIIT program comprised three sessions per week of high-intensity bursts (i.e., 120 percent peak rate of oxygen consumption [VO2peak]), of exercise interspersed with low-intensity exercise for a total of 20 to 24 minutes per session. The CONT group performed continuous exercise at 50 to 65 percent VO2peak for a total time of 36 to 48 minutes per session. The protocol was designed such that both exercise groups would generate an isocaloric energy expenditure. The PLA group performed a sham exercise program of stretching, self-massage, and fitball designed not to elicit any cardiometabolic improvements.

After 12 weeks of exercise, improvement in fitness measure by Wpeak was similar in the HIIT and CONT group and significantly better than the PLA group. These results demonstrated the benefit of HIIT being able to produce improvement in fitness level with only 50 to 60 percent of the time commitment compared with CONT. However, the CONT group showed a reduction in total body fat, whereas the HIIT group did not. The authors found that while HIIT is a time-effective means of achieving improved fitness, it did not reduce total body fat and android fat in previously inactive, overweight adults when compared to continuous aerobic exercise. They concluded HIIT should not be promoted as a time-effective means of increasing fat loss and improving fat distribution for the patient population with overweight.

Similarly, Kemmler et al[10] found that HIIT provided more weight loss than moderate intensity continuous exercise (MICE) but resulted in no difference in body fat mass. In this study, 81 participants were randomized to a HIIT group, MICE group, or control group for 16 weeks. The HIIT group ran for a total of 25 to 45 minutes per session. During the high-intensity phase, participants ran at 85 to 97.5 percent of their maximum heart rate followed by low-intensity jogging or fast walking at 65 to 70 percent of their maximum heart rate. The MICE group ran from 35 to 90 min per session to maintain at a constant pace to maintain 70 to 82.5 percent of their maximum heart rate. The protocols were designed to generate isocaloric conditions and comparable workload in both exercise groups. Exercise sessions increased from two sessions per week at baseline to 3 to 4 sessions per week after Week 8. At 16 weeks, both groups showed significant but comparable reductions in metabolic risk factors compared to the control group. The MICE participants saw a greater reduction in weight compared to the HIIT participants. However, body composition analysis found that the reduction in body fat was similar for both exercise groups and the greater reduction in body weight loss for MICE was due to a decrease in lean body mass.

Conversely, a study by Martins et al11 did not elicit any significant difference between HIIT, short-duration HIIT (1/2HIIT), and moderate-intensity continuous training (MICT) on body composition or cardiovascular fitness. In this study, 46 sedentary individuals with obesity were randomly assigned to one of three groups: HIIT, 1/2HITT, or MICT for 12 weeks. Each group participated in stationary bicycling three days per week. The HIIT protocol comprised eight seconds of sprinting followed by 12 seconds of recovery to induce an energy expenditure of 250 kcal. The 1/2HIIT protocol was identical to the HIIT protocol except it was limited to induce only 125 kcal expenditure. The MICT group participated in continuous cycling at 70 percent of maximum heart rate for a 250 kcal expenditure. Each of the groups experienced improvements in body composition (loss of fat and increase in fat free mass) and cardiovascular fitness, though no form proved significant in these areas.

Discussion

Professional guidelines and the available literature highlight that the benefits of exercise for treatment of overweight and obesity should not be measured by counting caloric expenditure alone. While the law of thermodynamics does apply, the complexities of human physiology determine changes in body composition in response to exercise. Also, it is well known that there is large variability in individual response to exercise.[12]

Though most recommendations for treatment of overweight and obesity include exercise, meta-analyses have demonstrated that the addition of exercise to a diet program provides only nominal improvements in weight loss.[13] However, we do know that improvements in T2DM and reduction in abdominal fat can be obtained even when exercise produces no weight loss benefit.[14,15] Given that lack of time is the number one reported barrier to an individual’s participation in regular physical activity,[16] HIIT might be advantageous in acquiring similar cardiovascular fitness compared to exercise of a longer duration. HIIT also appears to be better at maintaining muscle mass than traditional continuous exercise; however, these studies demonstrate that continuous exercise appears to be more effective for weight loss and specifically for causing loss of fat mass. Research provides some insight into HIIT and its effect on obesity, though it is important to note that there is wide variability in HIIT across studies regarding length of exercise, type of exercise, and measurement of “high-intensity;” therefore, these results might not be generalized to all types or durations of HIIT.

Conclusion

Studies available on HIIT in the patient population with overweight and obesity remain limited by their short duration, small number of participants, and variation in intensity and duration of “on” intervals; therefore, further research is needed.

As with many other medical regimens, exercise can be a joint decision that includes input from the patient. When prescribing exercise regimens to patients, clinicians might aim to learn what type of exercise the individual enjoys and can perform regularly. This approach supports the old adage that the best exercise we can prescribe for our patients is the one they are willing to do. If a patient expresses interest in HIIT, encourage him or her to evaluate the available evidence while considering the safety of the exercise according to their current physical state, which can be assessed by an appropriate pre-exercise screening test.

References

  1. Keating SE, Machan EA, O’Connor HT, et al. Continuous exercise but not high intensity interval training improves fat distribution in overweight adults. J Obes. 2014;2014:834865.
  2. U.S. Department of Health and Human Services. 2008 Physical Activity Guidelines for Americans. Washington, DC: U.S. Department of Health and Human Services, 2008.
  3. Wing R, Phelan S. Long-term weight loss maintenance. Am J Clin Nutr. 2005 Jul;82(1 Suppl):222S–225S.
  4. Jensen, MD, Ryan DH, Apovian CM, et al. 2014. 2013 AHA/ACC/TOS Guideline for the Management of Overweight and Obesity in Adults. Circulation. 2014;129(25 Suppl 2):S102–138.
  5. Garvey WT, Mechanick JI, Brett EM, et al. American Association of Clinical Endocrinologists and American College of Endocrinology comprehensive clinical practice guidelines for medical care of patients with obesity. Endocr Pract. 2016;22 Suppl 3:1-203.
  6. Tjønna AE, Lee SJ, Rognmo Ø, et al. Aerobic interval training versus continuous moderate exercise as a treatment for the metabolic syndrome: a pilot study. Circulation. 2008;118(4):346–354.
  7. Hood MS, Little JP, Tarnopolsky MA, Myslik F, Gibala MJ. Low-volume interval training improves muscle oxidative capacity in sedentary adults. Med Sci Sports Exerc. 2011;43(10):1849–1856.
  8. Burgomaster KA, Howarth KR, Phillips SM, et al. Similar metabolic adaptations during exercise after low volume sprint interval and traditional endurance training in humans. J Physiol. 2008 Jan 1;586(1):151–160. Epub 2007 Nov 8.
  9. Richards JC, Johnson TK, Kuzma JN, et al. Short-term sprint interval training increases insulin sensitivity in healthy adults but does not affect the thermogenic response to β-adrenergic stimulation. J Physiol. 2010;588(Pt 15):2961–2972.
  10. Kemmler W, Scharf M, Lell M, Petrasek C, Von Stengel S. 2014. High versus moderate intensity running exercise to impact cardiometabolic risk factors: the randomized controlled RUSH-study. BioMed Research International, vol. 2014, Article ID 843095, 10 pages, 2014.
  11. Martins C, Kazakova I, Ludviksen M, et al. High-intensity interval training and isocaloric moderate-intensity continuous training result in similar improvements in body composition and fitness in obese individuals. Int J Sport Nutr Exerc Metab. 2016;26(3):197–204.
  12. King NA, Hopkins M, Caudwell P, Stubbs RJ, Blundell JE. Individual variability following 12 weeks of supervised exercise: identification and characterization of compensation for exercise-induced weight loss. Int J Obes (Lond). 2008;32(1):177–184. Epub 2007 Sep 11.
  13. Klem ML, Wing RR, McGuire MT, Seagle HM, Hill JO. A descriptive study of individuals successful at long-term maintenance of substantial weight loss. Am J Clin Nutr. 1997;66(2):239–246.
  14. Lee S, Kuk JL, Davidson LE, et al. Exercise without weight loss is an effective strategy for obesity reduction in obese individuals with and without type 2 diabetes. J Appl Physiol (1985). 2005;99(3):1220–1225. Epub 2005 Apr 28.
  15. Ross R, Dagnone D, Jones PJ, et al. Reduction in obesity and related comorbid conditions after diet-induced weight loss or exercise-induced weight loss in men. A randomized, controlled trial. Ann Intern Med. 2000;133(2):92–103.
  16. Trost SG, Owen N, Bauman AE, Sallis JF, Brown W. Correlates of adults’ participation in physical activity: review and update. Med Sci Sports Exerc. 2002; 34(12):1996–2001.

 

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