Benefits and Effects of Youth and Adolescent Exercise
By John R. Mishock, PT, DPT, DC
Potential Health and Fitness Benefits of Youth Exercise
In youth and adolescence, there are many health and fitness benefits associated with regular physical activity. Physical activity is essential for normal growth and development. Regular exercises can improve cardio respiratory fitness, facilitate weight control, strengthen bones, enhance psycho-social well-being, improve motor performance skills, and prevent injury. (1)
For youth or adolescent with obesity issues, it has been observed that participation in a 16-week resistance training program can significantly decreased body fat and increased insulin sensitivity.2
For those individuals who are at risk for type II diabetes, research has identified muscular strength as an independent predictor of better insulin sensitivity in children aged 10-15 years. (3)
Studies indicate that regular participation in sports and resistance training can stimulate and increase bone density in both young boys and girls.(4,5,6,7,8,9)
There are over 850 evidence based research articles, recommending that school-age youth participate in 60 minutes or more of moderate to vigorous physical activity every day. The World Health Organization and The US Department of Health and Children has further advocated a minimum of 60 minutes daily of physical activity in youth and adolescent individuals. (10,11,12)
The 60 minutes of physical activity can be attained in; physical education class, recess, sport programs, school activities and exercise routines. Research demonstrates that 60 minutes or more of daily physical activity may be needed to offset the growing trend in youth and adolescent inactivity that is leading to an epidemic of deconditioning and obesity.
Children and teenagers need physical activity for normal growth and development. They need substantial amount of time to develop basic movement patterns and strength. Due to the child’s developmental needs, they require even more physical activity than adults. There is significant evidence that supports the fact that exercise and resistance training can be performed in a safe and effective manner. (13)
Psycho-social and Well-being of Youth Exercise Programs
Beyond the physical benefits of exercise on physical health there is also data to support the psycho-social benefits such as; enhance mental health, improved mood, better self-esteem, and well-being.(14,15,16,17) When children perform regular exercise they have positive changes in socialization and mental discipline similar to those in team sport participation.(18) These positive attitudes from exercise and resistance training can then be transferred towards positive feeling about physical education, physical fitness, and lifelong exercise.(19)
Ultimately, by creating good health habits in young people, there can be carry-over of those principles into adulthood thereby reducing their risk of disease and improving quality of life during the aging process.(20,21,22) There is mounting evidence to the mental and psycho-social benefits of exercise, leading to another compelling reason to encourage children and adolescents to participate in regular physical activity and exercise at an early age.
Enhanced Motor Performance Skills and Improved Athleticism through Exercise
Many scientific articles our touting the evidence that children and adolescents can significantly increase their speed, endurance, strength, agility, quickness and power above and beyond what growth and maturation will give them with the proper training program.(23,24,25,26,27,28,29,30,31)
Studies involving basketball, swimming, ice hockey, baseball, softball, tennis, lacrosse, football and soccer have noted the importance of incorporating resistance exercise into the sports training program to maximize gains in strength and power in young athletes. A well-designed sports specific training program including; resistance, plyometric, speed and agility will result in a significant degree of improvement in athletic development and performance.(32,33,34,35)
Studies have demonstrated that children and adolescents can improve specific athletic skill in; long-jump, vertical jump, sprint speed, agility, and medicine ball toss after specific exercise and performance training (resistance training with weight machines, free weights, body weight strength exercises, and medicine ball routines.(36,37,38,39,40)
Further improving the potential for athleticism was the finding that a combination of resistance and plyometric training can give greater benefits than when each was done alone.(41,42)
In the “Train 2 Play Method” we use the scientific evidence of the synergy of resistance and plyometric training in a functional sports specific manner to create optimal athleticism that ultimately will enhance sports performance.
There has been much debate on how much prepubescent athletes can improve in strength and endurance due in part to the fact that they do not have an abundance of hormones such as Testosterone or Growth Hormone in their systems. However, one study demonstrated 74% improvements in strength gains after a 8 weeks of progressive resistance training program.(43)
This type of gain may not be typical but most studies indicate that the young athlete should gain up to 30% in strength, endurance, speed and power after a short-term (8-20 weeks) youth training programs.(44,45,46)
Based on Selye’s General Adaptation Syndrome, whether young or old, the human body will have specific adaptations to an imposed demand (SAID principle) with any repeated activity or training.(47,48,49,50) Another words, the body will respond in a specific manner based on the training.
Isolated body movement exercises, (ie. One joint body movements) that are trained repetitively do not necessarily transfer benefits to functional tasks in sports. Whereas, if the exercise is specific and fundamental to the skill needed in the sport there will be a high degree of transfer to enhance the sports performance as well as prevent injury.(51)
In children and adolescents training adaptations are specific to the movement pattern, velocity of movement, contraction type, and contraction force.(52, 53) The athlete must train as specific as possible to the needs and demand of the sport.
For example, a baseball player performing isolated bicep curl exercises. This exercise will have limited benefit to enhanced sports performance. On the other, medicine ball rotational exercises in a specific pattern relative to the baseball swing will cause adaptive changes that will enhance sports performance. Based on the SAID principle, training the isolated movement of the bicep curl will cause isolated muscle hypertrophy (growth), however, that hypertrophied biceps muscle may not enhance the quality or efficiency of the movements needed in baseball.
The research clearly indicates, that in order to enhance sports performance the focus of training must be on functional integrated movement patterns rather than merely isolated training of individual muscles and joints.(54)
Sports-Related Injury Prevention through Exercise
Young athletes are playing more sports than ever; games all year round, multiple sports teams, inadequate rest periods in season and between seasons and early sports specialization. This new found philosophy on youth and adolescent sports has led to an inordinate amount of sports related injuries.(55,56) Much of these injuries are related to ill-prepared or improperly trained young athletes.(57)
It is theorized that we start playing organized sports so early that we may miss critical time periods or physiological windows where the child develops agility, balance, coordination, strength (ABC’S), and motor control through play. Also, there is a significant reduction in “free play” due to inactivity and excess screen time (TV, smart phone and pads). The days of riding your bike around town, playing at the play-ground, climbing trees, playing tag or dodge ball, pick-up games of basketball or baseball… seem to have passed us bye. Instead parents drive their kids to and from organized practices and games that are sports specific and not necessarily athletically developmental. More than ever, children spend more time in front of a screen, be it a smart phone, video game or TV. This lack of physical activity may then lead to a lack of “relative max strength” (maximum strength relative to one’s body). This lack of base strength in adolescents creates a poor foundation for future athletic development. The lack of core, upper and lower body strength is essential as a base to build dynamic balance, power, speed, agility and quickness. There early periods of youth development, are critical windows of time for the development of the ability to; run, jump, skip, change direction, kick a ball, throw a ball, hit, and swing. Without these rudimentary physical traits, the young athlete may not be prepared physically for the demands of sports practice and competition.(58,59) Along with the excessive amount of seasons and games, the young athlete has an increased likelihood of overuse leading to the near epidemic of youth and adolescent injuries seen in our orthopedic physical therapy clinics today.
These injuries in youth sports are a significant financial cost to the health care system. Beyond this, it often cause athletes to drop out of sports and physical activity altogether.(60)
The total elimination of sports-related injuries is unrealistic; however, an appropriately designed exercise program that includes; resistance and plyometric training may help reduce the likelihood of sports-related injuries in young and adult athletes.(61,62,63,64)
In a few studies, it has been suggested that if the athlete is trained appropriately (conditioning, strengthening, muscle imbalances correction, balance, coordination, and correcting training errors) up to 50% of injuries could be reduced.(65, 66)
Based on the evidence, a comprehensive conditioning program, that included resistance, speed, balance and plyometric training, has been shown to be an essential strategy for reducing the epidemic of sports related injuries in our young athletes.(67,68,69,70)
In the Train 2 Play writings, my focus is to enhance sports performance and prevent injury through scientifically based exercise and training programs.
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