High Intensity Interval Training and It’s Effective Use of Your Time

Running head: HIIT and your time

High Intensity Interval Training and It’s Effective Use of Your Time

Daniel D. Condo

Rowan University

Introduction:

One of the most common problems facing people who work-out, or want to work-out, is finding enough time throughout the course of the day/week (Godin, et al., 1994). High Intensity Interval Training (HIIT) is a form of interval training that combines quick but intense periods of anaerobic exercise, like sprinting and/or plyometrics, with short periods of rest. HIIT sessions can be as short as 5 to 25 minutes and are proven to be effective ways of improving cardiovascular health, improving VO2 max(maximum use of oxygen), losing weight and body fat, and increasing strength (Fisher, et al., 2015; Buckley, et al., 2015). Research also shows that HIIT can be as effective, if not more effective, in improving overall health as other more conventional exercise modalities like aerobic training or anaerobic strength training (Fisher et al., 2015). So, in a world where many people feel “there aren’t enough hours in a day”, HIIT could potentially be the most productive use of your time working out.

Research Question:

Is High Intensity Interval Training an equally practical, yet more efficient use of your time working out than more conventional training methods? Does it elicit similar or better health and fitness improvements in a shorter commitment of time?

Significance Statement:

Improving fitness levels is an effective way to improve overall health and increase longevity, and now, more than ever, fitness is gaining popularity, especially with young adults (Turk, S., 2016). Yet, obesity rates continue to rise in America (Ogden, et al., 2015) while our free time seems to diminish. One group facing a huge crunch for time is college students. This study will overview research of the results of HIIT and examine the perceived time efficiency among busy college students. If HIIT is proven to be an equally effective workout while using up less time, it can be prevalent to anyone looking to get in shape on a limited time schedule.

REVIEW OF LITERATURE:

HIIT is a form of anaerobic exercise, which means your heart rate is at 80% or more of its maximum rate and your body is working so hard that it metabolizes energy without using oxygen but instead uses phosphates and forms of glucose. Keep in mind, that glycogen is the stored version of glucose, which you could find in adipose tissue (fat). Aerobic exercise is generally longer and less intense with your heart rate operating at 60-80% of its max and relies on oxygen to metabolize energy. It seems to be the spike in heart rate that is the prominent factor in the effectiveness of HIIT. In this review we will compare continuous moderate-intensity training (CMIT) to HIIT and their effects on calorie control, health benefits, and your time.

Calorie Control:

In a study done by Skelly, et al. (2014) they measured the 24-hr energy expenditure of subjects participating in CMIT versus those using HIIT. The researchers closely monitored the subjects’ heart rate (HR) and oxygen consumption (VO2) during their respective exercise programs and throughout the rest of their day. During treatment VO2 was greater in the CMIT group than HIIT, but in the hours of recovery afterwards VO2 measured higher in the HIIT group (Skelly, et al., 2014). Similarly, the mean HR of the CMIT group was higher during the exercise than the HIIT group, but greater in the HIIT group in the hours following (Skelly, et al., 2014). The CMIT group worked for 53 minutes per session and used much more mechanical work, while the HIIT group only worked for a total of 22 minutes per session and required much less mechanical work. The study found that while energy expenditure was lower during HIIT versus MIT, 24-hr energy expenditure was similar between the two (Skelly, et al., 2014). So, despite requiring much less time and mechanical work, HIIT elicits similar energy expenditure as a bout of CMIT and seems to burns calories through the remainder of the day.

HIIT can also help with calorie control through its effects on appetite suppression (Alkahtani, et al., 2013). In the study done by Alkahtani et al. (2013), their 10 subjects were put through 4 weeks of CMIT and through 4 weeks of HIIT and then monitored their food preferences after each session. Each session had the subjects work until they burned the equivalent amount of calories between CMIT and HIIT. After HIIT sessions, subjects felt less hungry and had less desire to eat than CMIT sessions. Also, they found that CMIT sessions triggered much stronger cravings for High-fat non-sweet and High-fat sweet foods than the HIIT sessions. Kissileff et al. (1990) found that meals eaten after HIIT were smaller than those consumed after CMIT. Its been thought that one of the reasons HIIT results in greater fat loss than CMIT is its impact on food intake and appetite suppression (Boutcher, 2011). Whether that is true or not, it seems that HIIT is a better strategy than CMIT for someone implementing diet with a workout program (Alkahtani, et al., 2013).
Comparable Health Benefits:

In a study where 28 obese males were split into random CMIT and HIIT groups, Fisher et al. (2015) found that both groups improved their insulin sensitivity, decreased their blood lipids, decreased their % of body fat, and improved their cardiovascular fitness. While both groups showed improvement in cardiovascular fitness, the CMIT group achieved significantly greater improvements in endurance and blood pressure (Fisher, et al., 2015). Otherwise, the HIIT group showed similar results in reduction of weight, cholesterol, and triglycerides, but better results in increased peak power despite devoting ¼ of the time that the CMIT group needed (Fisher, et al., 2015).

Nicklas et al. (2004) recognized that abdominal visceral fat (AVFA) is strongly associated with health complications including type 2 diabetes and cardiovascular disease (CVD). In a study by Zhang et al. (2015) they found that HIIT produced a greater reduction in abdominal sub-cutaneous fat (ASFA) and AVFA than CMIT in overweight Chinese women. While the HIIT group used more time overall per session than the CMIT group, they spent half the time as the CMIT group doing actual mechanical work. Also, similar to the Fisher et al. (2015) study, all the women showed similar reductions in weight, BMI, and % body fat while the HIIT group showed greater improvements in their triglycerides and total cholesterol (Zhang, et al., 2015).
Time Crunch:

As seen in most of the aforementioned studies, HIIT seemingly produces similar, if not better, results in daily EE, appetite suppression, improving cardiovascular fitness, reduction in % of body fat, and reducing risk of CVD than CMIT all while using an equal or lessor time commitment. In the exception of the Zhang et al. (2015) study, where the obese women spent more time per session on HIIT, it can be concluded that the 40 minutes they spent on recovery could be altered to better fit those of different age groups and fitness levels (Mair, et al., 2016). If you are looking to improve overall health in a time efficient manner it seems that HIIT is a better method than CMIT to do so. It can be concluded that the spike in heart rate is the determining factor in its effectiveness over CMIT. In fact, Irving et al. (2008) believes that HIIT appears to be more effective in inducing secretion of lipolytic hormones than CMIT, which may facilitate greater post-exercise EE and fat oxidation. So, even when you’re not working out anymore, HIIT is still working towards your fitness goals.

METHODS:

To determine if participants perceive HIIT as an equally effective yet more time-efficient workout than CMIT, this study will interview 10 full-time Rowan University students who attend one Insanity group fitness class offered at the REC center. Subjects will then answer a 3-question survey on a scale of from 1-10, ranging from “less effective” to “more effective” than continuous moderate-intensity training. Subjects will have to have participated previously in some form of CMIT.

SURVEY COMPARING

HIGH-INTENSITY INTERVAL TRAINING (HIIT)

AND

CONTINUOUS MODERATE-INTENSITY TRAINING (CMIT):

1. How effective do you believe HIIT is in achieving similar energy expenditure as CMIT?

1 2 3 4 5 6 7 8 9 10

Not Effective Effective Very Effective

2. How effective do believe HIIT is compared to CMIT, when it comes to improving cardiovascular health and managing body fat?

1 2 3 4 5 6 7 8 9 10

Less Effective Equally Effective More Effective

3. When considering achieving YOUR personal fitness and health goals, and the time commitment required in reaching those goals within each modality: How efficient do you believe HIIT is compared to CMIT?

1 2 3 4 5 6 7 8 9 10

Less Efficient Equally Efficient More Efficient

RESULTS:

Immediately after their Insanity workout, subjects filled out their surveys and the results were very consistent. On a scale of 1 to 10 (1= Not Effective, 5=Effective, 10= Very Effective), when asked whether they believed HIIT was effective in achieving similar energy expenditure as CMIT, the group had an average rating of 7.4. When asked how effective they believed HIIT was in comparison to CMIT in improving cardiovascular health and managing body fat, subjects gave it an average rating of 6.9 (1= Less Effective, 5= Equally Effective, 10= More Effective). Finally, when ask to consider they’re own personal health and fitness goals and the time it would take to achieve those goals using HIIT compared to CMIT, students gave it an average rating 7.6 (1= Less Efficient, 5= Equally Efficient, 10= More Efficient).


DISCUSSION:

If you’re a person with a limited amount of time and you are looking to improve your overall and fitness, it is fair to say that HIIT is an efficient way to do so. Not only does HIIT elicit similar fitness results to CMIT, but it does so with less time commitment. Although it seems CMIT is better at improving cardiovascular endurance, HIIT is more effective in developing peak power and burning body fat. Most subjects perceived HIIT to be equally, if not more effective than CMIT in; expending energy, improving health and fitness, and usage of time.

HIIT is an equally practical workout modality because it can be done in almost any setting as long as you can achieve high enough heart rate. HIIT could be the answer to everyone pray for a “quick fix” when trying to lose weight and see results, but this study did not take into effect how the intensity of HIIT could be a deterrent to people who aren’t up for its challenging nature. HIIT is proven to be an effective workout modality, but whether people are willing to put in the work remains to be seen.

REFERENCES:

Skelly, L. E., Andrews, P. C., Gillen, J. B., Martin, B. J., Percival, M. E., & Gibala, M. J. (2014). High-intensity interval exercise induces 24-h energy expenditure similar to traditional endurance exercise despite reduced time commitment. Appl. Physiol. Nutr. Metab. Applied Physiology, Nutrition, and Metabolism, 39(7), 845-848. doi:10.1139/apnm-2013-0562

Zhang, H., Tong, T. K., Qiu, W., Wang, J., Nie, J., & He, Y. (2015). Effect of High-Intensity Interval Training Protocol on Abdominal Fat Reduction in Overweight Chinese Women. Kinesiology.

Fisher, G., Brown, A. W., Brown, M. M., Alcorn, A., Noles, C., Winwood, L., . . . Allison, D. B. (2015). High Intensity Interval- vs Moderate Intensity- Training for Improving Cardiometabolic Health in Overweight or Obese Males: A Randomized Controlled Trial. PLOS ONE PLoS ONE, 10(10). doi:10.1371/journal.pone.0138853

Mair, J. L., Nevill, A. M., De Vito, G., & Boreham, C. A. (2016). Personalized Prescription of Scalable High Intensity Interval Training to Inactive Female Adults of Different Ages. PLOS ONE.
Alkahtani, S. A., Byrne, N. M., Hills, A. P., & King, N. A. (2013). Interval Training Intensity Affects Energy Intake Compensation in Obese Men. International Journal of Sport Nutrition and Exercise Metabolism.
Irving, B.A., Davis, C.K., Brock, D.W., Weltman, J.Y., Swift, D., & Barrett, E.J. (2008). Effect of exercise training intensity on abdominal visceral fat and body composition. Medicine and Science in Sports and Exercise, 40, 1863-1872.

Godin, G., Deshamais, R., Valois, P., Lepage, P., Jobin, J., & Bradet, R. (1994). Differences in perceived barriers to exercise between high and low intenders: Observations among different populations. American Journal of Health Promotion, 8, 279-285.

Boutcher, S.H. 2011. High-intensity intermittent exercise and fat loss. J. Obes. 2011: Article ID 868305. doi:10.1155/2011/868305. PMID:21113312
Kissileff, H.R., Pi-Sunyer, F., Segal, K., Meltzer, S., & Foelsch, P. (1990). Acute effects of exercise on food intake in obese and nonobese women. The American Journal of Clinical Nutrition, 52(2), 240–245. PubMed