Research Facts About HIIT Workout (High Intensity Interval Training)

Research Facts About HIIT Workout (High Intensity Interval Training). This article will let us discuss about some of the facts about the research HIIT workout method (High Intensity Interval Training). The following will be disclosed process of establishing energy and burning calories based on the journals research on the metabolism when doing physical exercise, especially exercise using HIIT Method.

Physical training by the method of High Intensity Interval Training (HIIT) is very popular in the fitness industry in 2014. This type of training session included a short blast on our bodies from seconds to 4 minutes of intense exercise interspersed with rest periods (Kessler et al, . 2012, Boutcher 2011).

HIIT workout includes a wide range of activities are endless including weight lifting movement, power lifting, plyometrics, sprints, physical activity such as pushing and pulling, kind of exercise modes such as stationary bike, treadmills, elliptical training and much more.

Characteristic, HIIT is done as a training approach that is recommended for health, fitness and performance, the benefits are effective and efficient time to do because it does not require a very long time. Although many fitness centers that mention the many benefits of HIIT for health, but it must still be proved by concrete evidence that can be scientifically acceptable in order to strengthen the statement of the fitness center. Direct response from HIIT workout, physiologically will be explained below.

Direct Response Base on Physiology of HIIT workout (Boutcher 2011)

1. A very significant increase in heart rate
2. Epinephrine and Neuropineprin increased from 6.2 to 14.5 times greater than the standard.
3. At first the blood sugar (from the breakdown of glycogen) increased (to fuel exercise) but it is possible to decrease when doing HIIT workout.
4. ATP and phosphate creatin continued to decline (used to fuel the fast muscle contractions).
5. Increased blood levels of glycerol and free fatty acids begins with the initial breakdown of triglycerides.
6. Growth hormone increases up to 10 times above normal.
7. The blood flow of the veins increases to return to the heart.
8. Increased lactic acid levels up to 10 times the usual.
9. Work of Sympathetic nervous system increases (increases the speed of nerve impulses).
10. Decreased work of parasympathetic nervous system (decreasing the speed of nerve impulses)

How Big HIIT can Improve Cardiovascular Fitness?

A research on High Intensity Interval Training by Boutcher in 2011 revealed that HIIT can improve cardiorespiratory fitness (VO2max) 4% to 46% through the exercise period of 2 to 15 weeks.

Next research conducted by Kessler in 2012, which result that HIIT workout can increase VO2max faster. Boutcher continuing scientific explanations about improving VO2max through HIIT workout, increase VO2max such as the impact of increased stroke volume (the volume of blood pumped by the heart in one pulsation), which is caused by the ability of heart muscle contraction strong and fast. Additionally, Boutcher summarizes that HIIT also shown to improve mitochondrial biogenesis such as the size and number of mitochondria, the cells of ATP, which is ready to support the increase in cardiovascular capacity at every level of exercise intensity.

From a health perspective, an increase in VO2max is quite important, because of the low levels of VO2max can predict the lack of a functioning cardiovascular and become the cause of all deaths (Kessler et.al 2012).

What HIIT Influence on Insulin Resistance?

According to the American Diabetes Association (ADA, 2013), insulin sensitivity illustrates the ability of the body's cells to absorb glucose (also called glucose metabolism). It is generally increased during and after exercise. Boutcher (2011) and Kessler et al. (2012) comprehensively review studies that investigated the effects of HIIT in improving insulin sensitivity and glucose metabolism. 

The data indicate that insulin sensitivity can be increased by 23% to 58%. The length of study varies from 2 weeks to 16 weeks for the adaptation. The mechanism for these improvements seem well documented, with the ability of muscle contraction during exercise to stimulate glucose transporter (GLUT4 translocation known as) to take up glucose into the muscles that work (of blood), both available insulin or not (ADA, 2013).

What HIIT Effect on Cholesterol? 

Research about HIIT on koresterol conducted by Kessler in 2012 which summarizes 14 studies that have examined the effects of HIIT on cholesterol levels. The researchers explain that HIIT has been shown to increase HDL cholesterol after at least 8 weeks of training. The scientists showed that HIIT role in body fat reduction (or weight) is required to see an increase in total cholesterol, LDL cholesterol and triglyceride blood levels. 

Cholesterol is a substance that dissolves in fat that is transported in the blood by a special transporter called lipoproteins. Lipoprotein is an important part of a complex transportation system, which exchanges triglycerides between the liver, intestine, and peripheral tissues. Four major classes of lipoproteins are categorized as follows:

1. Chylomicron, which transports triglycerides and cholesterol of the small intestine,
2. Very Low Density Lipoprotein (VLDL), which is made in the liver for the transport of triglycerides (fat molecules in the human body),
3. Low Density Lipoprotein (LDL), VLDL metabolic products and a major transporter of cholesterol, and,
4. High Density Lipoprotein (HDL), sometimes called "good cholesterol" or "healthy", since it is responsible for the transport of cholesterol of the arterial wall to the liver, which is converted into bile and used for digestion or disposed of by the body. "The process of transport of cholesterol upside down ", it is believed that the HDL lipoprotein most beneficial in preventing heart disease

What HIIT Effect on Blood Pressure?

Still in the research conducted by Kessler in 2012, said about 12 studies that examined the effects on blood pressure HIIT. From the review, the authors argued that doing HIIT consistently for 10 weeks has not shown a significant effect on resting blood pressure (in people with hypertension). However, the researchers concluded that at least 12 weeks of HIIT is required for people with high blood pressure to have a positive effect and lowers blood pressure of 2% to 8% lower in the systolic and diastolic.

What HIIT Effect on Fat Loss and Body Weight Settings?

Boutcher (2011) observed that the striking surge in epinephrine and norepinephrine of HIIT training can serve the role of a catalyst to increase fat loss. Both of these have been shown to encourage lipolysis (breakdown of fat), and is largely responsible for the release of fat of fat storage that is both under the skin and in the muscles (which will be used to fuel the workout).

Summary of HIIT

The results of several studies on HIIT does make us stunned with the results of research that has revealed the results of them, a very significant result is an increase in VO2max is directly related to the increase in cardio protection of heart disease. Perhaps as important as the adaptation of maximum aerobic capacity, acute and chronic effects of HIIT is to improve insulin sensitivity. The effects of HIIT leads to a decrease in visceral fat and subcutaneous fat. And, the impact of HIIT has the ability to reduce systolic and diastolic blood pressure (when the elevated) and increase HDL cholesterol significantly.

Research evidence already exists and has been scientifically described. Please try and implemented the HIIT workout. Thank you,

Reference

American Diabetic Association. (2013). Blood Glucose Control and Exercise
http://www.diabetes.org/food-and-fitness/fitness/get-started-safely/blood-glucose-control-and-exercise.html

Blair, S.N. et al. (1996). Influences of cardiorespiratory fitness and other precursors on cardiovascular disease and all-cause mortality in men and women, The Journal of the American Medical Association, 276(3), 205-210

Boutcher, S. H. (2011). High-intensity intermittent exercise and fat loss. Journal of Obesity, 2011, Article ID868305, 10 pages, doi: 10.1155/2011/868305

Kessler, H.S., Sisson, S. B., Short, K.R. (2012). The potential for high-intensity interval training to reduce cardiometabolic disease risk. Sports Medicine, 42(6), 489-509.

Swain, D.P. and Franklin, B.A. (2006). Comparison of cardioprotective benefits of vigorous versus moderate intensity aerobic exercise. American Journal of Cardiology, 97: 141-147.
 

World Health Organization. (2013). Cardiovascular Diseases (CVDs)
http://www.who.int/mediacentre/factsheets/fs317/en/