Comparing the reinforcing value of high intensity interval training versus moderate intensity aerobic exercise in sedentary adults

High-intensity interval training exercise decreases brain CB1 receptor levels in male and female adult rats

The numerous health benefits of exercise are well-documented, including its efficacy in treating substance use disorders (SUDs). Several exercise regimens have been proposed; however, the most effective regimen for patients with addiction has yet to be elucidated. High-intensity interval training (HIIT) exhibits considerable potential compared to aerobic and resistance exercise. Dopamine signaling is recognized as a key neurobiological mechanism contributing to HIIT's therapeutic potential for SUDs; however, the role of the endocannabinoid system in this context is not well understood. The present study investigated the effects of HIIT exercise on endocannabinoid signaling by measuring cannabinoid receptor 1 (CB1R) binding in the brains of male and female rats using [3H]SR141716A autoradiography. Male and female rats were separated into sedentary and HIIT exercise groups. For six weeks, exercise was completed daily on a treadmill for 30 min (10 3-min intervals) progressively increasing speed to 0.8 mph (21.5 m/min). The HIIT program significantly reduced CB1R binding in both sexes across multiple brain regions, including the striatum, thalamus, and distinct areas of the cortex. Sex differences were observed wherein males exhibited greater CB1R binding than females across brain regions, including the cerebellum, striatum, and parts of the cortex. Males experienced an increase in mean cerebellum CB1R binding due to HIIT, whereas females showed no effect in this region. The results suggest HIIT exercise can modulate endocannabinoid signalling by way of decreased CB1R binding. These findings further support the intensity dependence of endocannabinoid modulation and highlight potential pathways for exercise-induced neurobiological and behavioural change.

Effects of combined high-intensity interval and moderate-intensity continuous training vs. moderate-intensity continuous training alone in male adolescents: a randomized controlled trial

INTRODUCTION

This study aims to investigate the combining effects of high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) compared to MICT alone on physical fitness, academic performance, and anxiety levels among adolescents in a school setting.

METHODS

Sixty male adolescents were randomly assigned to either an experimental group (HIIT + MICT) or a control group (MICT only) for 12 weeks. Physical fitness was assessed using lung capacity, a 50-meter sprint, a standing long jump, and a 1000-meter run. Anxiety levels were measured using the Zung Self-Rating Anxiety Scale, and cognitive performance through academic evaluations. Statistical analyses included Shapiro-Wilk, Mann-Whitney U, unpaired t-tests, chi-square, and McNemar tests.

RESULTS

After 12 weeks, the experimental group showed a significant increase in lung capacity (10.30 ml/kg) compared to the control group (3.18 ml/kg, P = 0.03). Sprint and run completion times were also significantly faster in the experimental group (P < 0.01 and P = 0.02), with greater improvements in the long jump (P = 0.01). Academic performance and anxiety levels improved significantly in the experimental group (P = 0.02 and P < 0.01), while the control group exhibited no significant changes.

CONCLUSION

This study demonstrated that combining HIIT with MICT results in greater improvements in adolescent cardiorespiratory fitness, anaerobic performance, academic outcomes, and anxiety levels compared to MICT alone. These findings support the incorporation of HIIT alongside traditional MICT in adolescents.

TRIAL REGISTRATION

The study was retrospectively registered in the clinical trials registry on 26/04/2023 (ChiCTR2300070895).

High intensity interval training exercise increases dopamine D2 levels and modulates brain dopamine signaling

Background

Previous research has outlined the health benefits of exercise including its therapeutic potential for substance use disorders (SUD). These data have already been utilized and it is now common to find exercise as part of SUD treatment and relapse prevention programs. However, we need to better understand different exercise regimens and determine which would be the most beneficial for SUDs. Recently, high intensity interval training (HIIT) has gained attention in comparison with aerobic and resistance exercise. Little is known regarding the neurobiological mechanisms of HIIT, including its effects on dopamine signaling and receptor levels in the brain. The present study examined the effects of chronic HIIT exercise on dopamine signaling as measured by dopamine type 1-like receptor (D1R)-like, dopamine type 2-like receptor (D2R)-like, and tyrosine hydroxylase (TH) quantification in the brains of male and female rats as measured by [3H] SCH 23390 and [3H] spiperone autoradiography, and TH-immunoreactive optical density values.

Methods

Rats were separated in two groups: sedentary and HIIT exercise. Exercise was on a treadmill for 30 min daily (10 3 min cycles) for six weeks with progressive speed increased up to 0.8 mph (21.5 m/min).

Results

Results showed for D2R-like binding, a significant effect across the ventral caudate putamen (V CPU) between sexes, such that mean D2R-like binding was 14% greater for males than females. In the nucleus accumbens shell (Nac Shell), the HIIT Exercise rats showed 16% greater D2R-like binding as compared to the sedentary rats. No significant effects of HIIT exercise were found across groups for brain D1R-like binding levels or TH expression.

Conclusion

These results suggest that HIIT exercise can modulate dopamine signaling by way of increased D2R. These findings support the premise that HIIT exercise plays an important role in dopamine signaling and, may provide a potential mechanism for how HIIT exercise can impact the brain and behavior.

EFFECTS OF HIGH-INTENSITY TRAINING ON BASKETBALL PLAYERS

ABSTRACT Introduction: Basketball represents much more than a high-intensity exercise. Like most ball games, it is a continuous movement system. Objective: Study the effect of high-intensity interval training (HIT) on the aerobic metabolism of young basketball players. Methods: The author randomly divided male basketball players into an upper limb HIT group, lower limb HIT group, and control group by experimental method and statistical analysis, the control group received routine training, and aerobic exercise capacity was measured by increasing load test before and after the experiment. Results: During the lower extremity experiment, the mean power (MP) and peak power (PP) of the 4th full-force pedal stroke in the lower extremity HIT group increased (P<0.05), and the T/C ratio of the lower extremity HIT group was also implemented (P<0.05). There was no significant change in the indices of the control group (P>0.05). Conclusion: Upper extremity HIT in young male basketball players improved only upper extremity aerobic exercise capacity. In contrast, lower-extremity HIT improved both upper-extremity aerobic exercise capacity and lower-extremity anaerobic exercise capacity. Level of evidence II; Therapeutic studies - investigating treatment outcomes.