The Effect of Intensity, Frequency, Duration and Volume of Physical Activity in Children and Adolescents on Skeletal Muscle Fitness: A Systematic Review and Meta-Analysis of Randomized Controlled Trials
Related Experiment Video
Updated: Oct 18, 2025

Short Session High Intensity Interval Training and Treadmill Assessment in Aged Mice
Published on: February 2, 2019
Chunchun Wu1, Yongjin Xu1, Zhaojing Chen2
1Department of Sports and Exercise Science, College of Education, Zhejiang University, Hangzhou 310000, China.
Abstract:
Physical activity could improve the muscle fitness of youth, but the systematic analysis of physical activity elements and muscle fitness was limited. This systematic review and meta-analysis aim to explore the influence of physical activity elements on muscle fitness in children and adolescents. We analyzed literature in Embase, EBSCO, Web of Science, and PubMed databases from January 2000 to September 2020. Only randomized controlled studies with an active control group, which examined at least 1 muscle fitness evaluation index in individuals aged 5-18 years were included. Articles were evaluated using the Jaded scale. Weighted-mean standardized mean differences (SMDs) were calculated using random-effects models. Twenty-one studies and 2267 subjects were included. Physical activity had moderate effects on improving muscle fitness (SMD: 0.58-0.96, p < 0.05). Physical activity element subgroup analysis showed that high-intensity (SMD 0.68-0.99, p < 0.05) physical activity <3 times/week (SMD 0.68-0.99, p < 0.05), and <60 min/session (SMD 0.66-0.76, p < 0.01) effectively improved muscle fitness. Resistance training of ≥3 sets/session (SMD 0.93-2.90, p < 0.01) and <10 repetitions/set (SMD 0.93-1.29, p < 0.05) significantly improved muscle fitness. Low-frequency, high-intensity, and short-duration physical activity more effectively improves muscle fitness in children and adolescents. The major limitation of this meta-analysis was the low quality of included studies. The study was registered in PROSPERO with the registration number CRD42020206963 and was funded mainly by the Ministry of Education of Humanities and Social Science project, China.
Related Concept Videos
Exercise 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...
Muscle Stimulation Frequency
Wave summation
At low firing rates, motor neurons induce individual twitch contractions in muscle fibers. These twitches...
Exercise and Cardiac Output
Sustained exercise increases the muscles' oxygen demand, which can be...
Exercise 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...
Disorders of the Skeletal Muscle
Musculoskeletal disorders
Musculoskeletal disorders involve injuries and conditions affecting the skeletal muscles and associated connective tissues. These disorders can arise from acute biomechanical stresses or chronic overuse and can occur across different age groups. Common injuries include sprains, fractures, and muscular strains, often resulting from...

