Overview: High-intensity interval training (HIIT) burns more fat than aerobic exercise, a new study finds.
Source: Victoria University Melbourne
“If that stubborn body fat doesn’t go away, consider adding High-Intensity-Interval-Training or HIIT to your exercise routine,” says Professor Zeljko Pedisic of Victoria University, Melbourne.
HIIT boosts fat burning more than aerobic exercise, finds a study published in the British Journal of Sports Medicine.
How was the research conducted?
The authors of the study pooled the results of 18 controlled intervention studies on the effects of HIIT on the rate of fat burning during exercise.
The intervention studies included a total of 511 adult participants who engaged in supervised HIIT, moderate-intensity aerobic exercise, or a no-exercise control group.
The duration of the exercise interventions ranged from 2 to 14 weeks. In almost all studies, participants did three HIIT sessions per week.
What are the main findings?
A few sessions of HIIT a week will turn your body into a fat-burning “machine”. HIIT makes you burn more fat, not only during the HIIT sessions, but also during other forms of physical activity, such as brisk walking, swimming and sports.
Fat metabolism will improve after just four weeks of HIIT, and it will continue to improve over time.
After 12 weeks of HIIT, every minute of physical activity is expected to burn 0.13 grams of extra fat. For someone who does 150 minutes of exercise a week, this can lead to about 10 kg of extra fat burning in a decade.
Overweight individuals can expect a greater increase in fat burning compared to individuals of “normal” weight.
While individuals could also improve fat metabolism by participating in aerobic exercise (eg jogging), this would require a much greater time commitment and the improvements would be smaller.
Why is this important?
These findings could help more than two billion overweight people worldwide (link is external) to improve their fat metabolism and reduce weight.
They can also help billions of others avoid unwanted weight gain over time.
“According to the recent Worldwide Survey of Fitness Trends (link is external), HIIT is one of the most popular types of workouts. If you’re not already doing it, maybe you should give it a try,” concludes Professor Pedisic.
About this movement research news
Author: press office
Source: Victoria University Melbourne
Contact: Press Office – Victoria University Melbourne
Image: The image is in the public domain
Original research: Closed access.
“Effects of high-intensity interval training (HIIT) and sprint interval training (SIT) on fat oxidation during exercise: a systematic review and meta-analysis” by Muhammed M Atakan et al. British Journal of Sports Medicine
Effects of high-intensity interval training (HIIT) and sprint interval training (SIT) on fat oxidation during exercise: a systematic review and meta-analysis
Exploring the effects of high-intensity interval training (HIIT) and sprint interval training (SIT) on exercise fat oxidation (FatOx) and how they relate to the effects of moderate-intensity continuous training (MICT).
Systematic review and meta-analysis.
Academic Search Ultimate, CINAHL, networked digital library of dissertations and dissertations, open access dissertations and dissertations, open dissertations, PubMed/MEDLINE, Scopus, SPORTDiscus, and Web of Science.
Eligibility criteria for selecting studies
Cross-group studies, involving adult participants who were not trained athletes, and evaluating effects of HIIT or SIT on FatOx (versus no exercise or MICT) were included.
Eighteen studies of fair to good quality were included; nine compare HIIT or SIT with no exercise and eleven compare HIIT or SIT with MICT. A significant pooled effect of this type of interval training on FatOx was found (mean difference in g/min (MD)=0.08; 95% confidence interval (CI) 0.04 to 0.12; p<0.001). Significant effects were found for training schedules lasting 4 weeks, and they increased with each additional training week (b= 0.01; 95% CI 0.00 to 0.02; p=0.003). HIIT and/or SIT were slightly more effective than MICT (MD=0.03; 95% CI 0.01 to 0.05; p=0.005). The effects on FatOx were greater in overweight/obese subjects.
Participation in HIIT or SIT may improve FatOx, with greater effects expected for longer exercise regimens and overweight/obese individuals. While some of the effects may seem small, they can be important in holistic approaches to improve metabolic health and manage obesity.