Related Experiment Video
Updated: Jan 9, 2026
A Real-World High-Intensity Interval Training Protocol for Cardiorespiratory Fitness Improvement
Published on: February 22, 2022
Eight weeks equivalent-volume RT and HIIT performed within same session or alternated weekly: comparative effects on
Yang Cheng1, Jing Ma1, Rongze Ye2
1School of Kinesiology and Health, Capital University of Physical Education and Sports, Beijing, 100191, China.
Background:
This study aims to investigate the effects of 8 weeks equivalent-volume resistance training (RT) and high-intensity interval training (HIIT) performed within same session or alternated weekly on body composition, cardiorespiratory function, and muscular fitness in young adult males.
Methods:
Twenty-three young adult males were randomly assigned to either the A group (RT and HIIT performed within the same session, n = 11) or the B group (RT and HIIT were alternated weekly, n = 12). Body composition, cardiorespiratory function, and muscular fitness were assessed at baseline (T1), the fifth week (T2), and the ninth week (T3). Baseline differences and training effects were analyzed using independent sample t-tests and repeated measures ANOVA, respectively.
Results:
No significant group differences were found at baseline (P > 0.05). Post-intervention, body fat percentage, skeletal muscle mass, and thickness significantly improved over time (P < 0.05), but no significant group or interaction effects. Maximum power output significantly increased at T2 and T3 compared to T1 (P < 0.05), while VO₂max, METs, and Maximum Minute Ventilation significantly increased only at T3 compared to T1 (P < 0.05), with no significant group or interaction effects. Both groups showed significant improvements in maximal strength during the intervention (P < 0.05). Endurance repetitions, particularly in the squat exercise, showed significant improvement initially (P < 0.05), followed by a downward trend, and no significant group or interaction effects were found.
Conclusions:
Concurrent training, whether performed within the same session or alternated weekly, elicited comparable improvements in body composition, cardiorespiratory, and muscular outcomes in young adult males. Both arrangements promoted beneficial adaptations, indicating flexibility in concurrent training design.
Trial Registration:
The study was retrospectively registered on 24 June 2025 at www.chictr.org.cn with identification number ChiCTR2500104848.
More Related Videos
Related Concept Videos
01:17Exercise and Cardiac Output
Sustained exercise increases the muscles' oxygen demand, which can be...
01:27Exercise and Muscle Performance
Endurance exercises
Endurance exercises involve running, swimming, or cycling, which require repetitive movements with low force output. When a person engages in endurance exercise, a few noticeable changes occur in their skeletal muscles. For instance, the number of capillaries...
01:19Cardiac Output I:Effect of Heart Rate on Cardiac Output
Cardiac output (CO) refers to the total amount of blood ejected by one of the ventricles in liters per minute (L/min). In a resting adult, CO ranges from 5 to 6 L/min, adjusting according to the body's metabolic requirements.
Effect of Heart Rate on Cardiac Output
Cardiac output adapts to metabolic demands during stress, physical activity, or illness. The autonomic nervous system regulates heart rate via the sinoatrial node. The parasympathetic nervous system decreases heart...
01:20Exercise and Cardiovascular Response
Light to moderate physical activity initiates a series of interconnected responses in the body. The heart rate modestly increases in anticipation of the workout, followed by widespread vasodilation as oxygen consumption by skeletal muscles increases. This results in decreased peripheral resistance, increased capillary blood flow, and accelerated...