Showing 3 results for High-Intensity Interval Training
Dr Fatemeh Kazeminasab, Miss Motahareh Mohebinejad, Dr Karim Azali Alamdari,
Volume 0, Issue 0 (11-2019)
Abstract
Background and purpose: Excessive fat deposition is associated with cardiovascular diseases, diabetes as well as hypertension. The aim of this study was to determine the net effect size of high intensity interval training (HIIT) on some factors associated with insulin sensitivity in adults with overweight and obesity.
Materials and methods: A search for English articles was conducted in Web of Science, Scopus, and PubMed databases without limiting the year of publication until February 2023. To calculate the effect size, WMD and 95% confidence interval were calculated using random effect model. Fixed effect model meta regression was used to determine treatment effects associations with other variables.
Results: In total, 13 studies with 446 adults with overweight and obesity (149 females, and 317 males) with 24.7-57 years old were included in the present meta-analysis. The results showed that HIIT caused a significant decrease in fasting glucose [WMD=-8.65 mg/dL, P=0.002], fasting insulin [WMD=-1.88 U/L P=0.005], and diastolic blood pressure (DBP) [WMD=-3.33 mmHg. Weak correlations were observed in between HIIT’s net effect on DBP and insulin (r=-0.32, p=0.019) as well as with subjects’ age (r=-0.29, p=0.037) respectively in meta-regression assessments.
Conclusion: The rate of DBP reduction is sharper and these changes are also correlated with age. Therefore, HIIT is suggested as a Non-pharmacological Approach to prevent against future cardiometabolic risk factors in this population.
Mr Hadi Habibi, Dr Ali Asghar Ravasi, Dr Neda Khaledi,
Volume 0, Issue 0 (11-2019)
Abstract
The impact of maternal physical activity on offspring health and phenotypic changes due to exercise has emerged as a significant area of interest in exercise physiology in recent years. Therefore, the aim of this study was to determine the effect of a maternal high-intensity interval training (HIIT) program on the expression of PGC1α and SIRT1 genes in the skeletal muscle of first-generation offspring in Wistar rats. Twenty-four 8-week-old female Wistar rats were acclimatized to the environment and then divided into three groups: a maternal control group, a maternal pre-pregnancy exercise group, and a maternal exercise group that trained both before and during pregnancy. The pre-pregnancy exercise regimen lasted 6 weeks, while the exercise during pregnancy lasted 3 weeks. The exercise protocol involved treadmill running, consisting of 5 days per week, with each session including 1 minute of running at 85-100% of VO2peak and a 10% incline, followed by 2 minutes of rest at 65% of VO2peak and 0% incline. The number of intervals started at 10 and increased based on the overload principle. The control group remained sedentary during this period. After the exercise period and the birth of the offspring, male offspring were categorized according to their maternal groups, and the expression levels of PGC1α and SIRT1 genes in their skeletal muscle were evaluated at 10 weeks of age. Data were analyzed using ANOVA and Tukey's post-hoc test.
The results indicated that after the 6-week HIIT program, both the pre-pregnancy exercise group and the group that exercised before and during pregnancy showed significant differences in speed and distance in the functional performance test compared to the control group (P < 0.05). Additionally, significant differences were observed in the expression of PGC1α and SIRT1 genes among the groups after the birth of the offspring. These differences were significant between the pre-pregnancy exercise group, the pre- and during-pregnancy exercise group, and the control group (P < 0.05). It appears that maternal exercise before and during pregnancy induces changes in the mitochondrial genotype of the offspring, with a more pronounced effect on the expression of mitochondrial genes such as PGC1α and SIRT1 when exercise occurs both before and during pregnancy compared to exercise before pregnancy alone.
Mr Aidin Zarifi, Dr Hamid Rajabi, Dr Sadegh Hasan Nia, Dr Mohamadreza Dehkhoda, Dr Babak Mirsoltani,
Volume 13, Issue 10 (10-2015)
Abstract
High-intensity interval training (HIT) induces skeletal muscle metabolic and performance adaptations that
resemble traditional endurance training despite a low total exercise volume. On the other hand, fatty acid
oxidation is increases in skeletal muscle with endurance training. This process is regulated in several sites,
including the transport of fatty acids across the plasma membrane. The transportation across this membrane is
recognized to be primarily protein mediated. Therefore, the purpose of this study was to determine the effect of
low-volume high intensity interval training on protein content of sarcolemmal fatty acids transporters (FAT/CD36
and FABPpm) in young men. Twenty recreationally active young men were assigned to a HIT (n=10, 19.3 yr old,
67.2 kg body wt, and 172.7 cm ht) or Control (n=10, 19.7 yr old, 65.9 kg body wt, and 174.4 cm ht) group. HIT
group performed three training sessions per week over 4 weeks. Each session consisted of 8-11×60 s intervals
at ∼100% of peak power output elicited during a ramp VO2peak test separated by 75 s of recovery. Skeletal
muscle (vastus lateralis) biopsy samples were obtained before and after training. HIT increased (17.5%)VO2peak (p<0.05). Also, after 4 weeks low-volume HIT, sarcolemmal content of CD36 and FABPpm increased
14 and 25 percent ,respectively (p<0.05). Therefore, the results showed that the practical model of low-volume
HIT could increase aerobic capacity and sarcolemmal content of CD36 and FABPpm. The increase indicates
that the facilitation of in muscle fatty acid transportation can be adapted which in turn increases the fat oxidation
capacity.
