The metabolic and cardiovascular effects and benefits of HIT
ACUTE
CHRONIC
Where does HIT fit?
An examination of the affective response to high-intensity intervals in comparison to continuous moderate- and continuous vigorous-intensity exercise in the exercise intensity-affect continuum.
Jung ME1, Bourne JE1, Little JP1.
Author information1School of Health and Exercise Sciences, University of British Columbia, Okanagan, British Columbia, Canada.
Abstract
Affect experienced during an exercise session is purported to predict future exercise behaviour. Compared to continuous moderate-intensity exercise (CMI), the affective response to continuous vigorous-intensity exercise (CVI) has consistently been shown to be more aversive. The affective response, and overall tolerability to high-intensity interval training (HIT), is less studied. To date, there has yet to be a comparison between HIT, CVI, and CMI. The purpose of this study was to compare the tolerability and affective responses during HIT to CVI and CMI. This study utilized a repeated measures, randomized, counter-balanced design. Forty-four participants visited the laboratory on four occasions. Baseline fitness testing was conducted to establish peak power output in Watts (W peak). Three subsequent visits involved a single bout of a) HIT, corresponding to 1-minute at ∼ 100% W peak and 1-minute at ∼ 20% W peak for 20 minutes, b) CMI, corresponding to ∼ 40% W peak for 40 minutes, and c) CVI, corresponding to ∼ 80% W peak for 20 minutes. The order of the sessions was randomized. Affective responses were measured before, during and after each session. Task self-efficacy, intentions, enjoyment and preference were measured after sessions. Participants reported greater enjoyment of HIT as compared to CMI and CVI, with over 50% of participants reporting a preference to engage in HIT as opposed to either CMI or CVI. HIT was considered more pleasurable than CVI after exercise, but less pleasurable than CMI at these times. Despite this participants reported being just as confident to engage in HIT as they were CMI, but less confident to engage in CVI. This study highlights the utility of HIT in inactive individuals, and suggests that it may be a viable alternative to traditionally prescribed continuous modalities of exercise for promoting self-efficacy and enjoyment of exercise.
J Diabetes Res. 2015;2015:191595. doi: 10.1155/2015/191595. Epub 2015 Mar 30.
Mekary RA, Grøntved A, Despres JP, De Moura LP, Asgarzadeh M, Willett WC, Rimm EB, Giovannucci E, Hu FB.
Obesity (Silver Spring). 2015 Feb;23(2):461-7. doi: 10.1002/oby.20949. Epub 2014 Dec 19.
ACUTE
- Maximal Local Aerobic Metabolism is achieved in working muscle tissue.
- There is an increase in oxygen consumption (VO2) consumption.
- There is an increase in blood lactate levels, as glucose is broken down and oxidized to pyruvate, which then produces lactate at an amount greater than the tissues can remove it.
- There is an increase in the adenosine monophosphate (AMP) to adenosine triphosphate (ATP) ratio due to the increased use of ATP for energy. This results in an increase in activity of the adenosine monophosphate-activated protein kinase pathway (AMPK).
- There is increased shear rate (flow velocity) of blood in the vasculature.
- There is an increase in peripheral vascular blood pressure (there is far less or no change in myocardial pressure).
- There is an increase in venous return of blood to the heart.
- There is an increase in left ventricular function (the left ventricle is responsible for pumping oxygenated blood into the body).
- There is an increase in heart rate, the number of times the heart beats per minute.
- There is an increase in cardiac output, as a greater volume of blood is pumped by the heart per minute.
CHRONIC
- Increase in mitochondrial enzymes
- Increase in mitochondrial proliferation
- Decrease in type IIx fibers
- Increase in type IIa and type I fibers
- Increase in capillary contacts
- Increase in capillary fiber ratio
- Increase in VO2 max
- Increase in economy of movement
- Decrease in resting heart rate
Where does HIT fit?
An examination of the affective response to high-intensity intervals in comparison to continuous moderate- and continuous vigorous-intensity exercise in the exercise intensity-affect continuum.
Jung ME1, Bourne JE1, Little JP1.
Author information1School of Health and Exercise Sciences, University of British Columbia, Okanagan, British Columbia, Canada.
Abstract
Affect experienced during an exercise session is purported to predict future exercise behaviour. Compared to continuous moderate-intensity exercise (CMI), the affective response to continuous vigorous-intensity exercise (CVI) has consistently been shown to be more aversive. The affective response, and overall tolerability to high-intensity interval training (HIT), is less studied. To date, there has yet to be a comparison between HIT, CVI, and CMI. The purpose of this study was to compare the tolerability and affective responses during HIT to CVI and CMI. This study utilized a repeated measures, randomized, counter-balanced design. Forty-four participants visited the laboratory on four occasions. Baseline fitness testing was conducted to establish peak power output in Watts (W peak). Three subsequent visits involved a single bout of a) HIT, corresponding to 1-minute at ∼ 100% W peak and 1-minute at ∼ 20% W peak for 20 minutes, b) CMI, corresponding to ∼ 40% W peak for 40 minutes, and c) CVI, corresponding to ∼ 80% W peak for 20 minutes. The order of the sessions was randomized. Affective responses were measured before, during and after each session. Task self-efficacy, intentions, enjoyment and preference were measured after sessions. Participants reported greater enjoyment of HIT as compared to CMI and CVI, with over 50% of participants reporting a preference to engage in HIT as opposed to either CMI or CVI. HIT was considered more pleasurable than CVI after exercise, but less pleasurable than CMI at these times. Despite this participants reported being just as confident to engage in HIT as they were CMI, but less confident to engage in CVI. This study highlights the utility of HIT in inactive individuals, and suggests that it may be a viable alternative to traditionally prescribed continuous modalities of exercise for promoting self-efficacy and enjoyment of exercise.
- Low-volume high-intensity interval training rapidly improves cardiopulmonary function in postmenopausal women.[Menopause. 2014]
- Review Comparison of cardioprotective benefits of vigorous versus moderate intensity aerobic exercise.[Am Jung}
- High-intensity interval training as an efficacious alternative to moderate-intensity continuous training for adults with prediabetes.
J Diabetes Res. 2015;2015:191595. doi: 10.1155/2015/191595. Epub 2015 Mar 30.
- Effectiveness of High-Intensity Interval Training (HIT) and Continuous Endurance Training for VO2max Improvements: A Systematic Review and Meta-Analysis of Controlled Trials. Gist, Nicholas H.; Freese, Eric C.; Cureton, Kirk J. Journal of Strength and Conditioning Research: November 2014 - Volume 28 - Issue 11- p 3033–3040
- Changes in mitochondrial function and mitochondria associated protein expression in response to 2-weeks of high intensity interval training.
Mekary RA, Grøntved A, Despres JP, De Moura LP, Asgarzadeh M, Willett WC, Rimm EB, Giovannucci E, Hu FB.
Obesity (Silver Spring). 2015 Feb;23(2):461-7. doi: 10.1002/oby.20949. Epub 2014 Dec 19.