ArticlePDF AvailableLiterature Review

Strength Training for Children and Adolescents: Benefits and Risks

Authors:

Abstract

Physical activity has proved to be an effective means of preventing several diseases and improving general health. In most cases, though, light to moderate efforts are suggested, for both youngsters and adults. Common sense advices call for late inception of intense, strength training-related activities, like weight lifting and plyometrics, which are usually postponed at the end of the growth age, even among sport practitioners. However, such advices seem to have a mainly an-ecdotal nature. The purpose of this review is to evaluate risks and benefits of early inception of strength training, at adolescence or even earlier, and to verify whether concerns can be grounded scientifically. Current literature does not seem to have any particular aversion against the practice of strength training by children and adolescents, provided that some safety rules are followed, like medical clearance, proper instruction from a qualified professional and progressive overload. At the same time, several studies provide consistent findings supporting the benefits of repeated, intense physical efforts in young subjects. Improved motor skills and body composition, in terms of increased fat free mass, reduced fat mass and enhanced bone health, have been extensively documented, especially if sport practice began early, when the subjects were pubescent. It can be therefore concluded that strength training is a relatively safe and healthy practice for children and adolescents.
Coll. Antropol. 37 (2013) Suppl. 2: 219–225
Review
Strength Training for Children and Adolescents:
Benefits and Risks
Davide Barbieri and Luciana Zaccagni
University of Ferrara, Department of Biomedical and Specialty Surgical Sciences, Ferrara, Italy
ABSTRACT
Physical activity has proved to be an effective means of preventing several diseases and improving general health. In
most cases, though, light to moderate efforts are suggested, for both youngsters and adults. Common sense advices call
for late inception of intense, strength training-related activities, like weight lifting and plyometrics, which are usually
postponed at the end of the growth age, even among sport practitioners. However, such advices seem to have a mainly an-
ecdotal nature. The purpose of this review is to evaluate risks and benefits of early inception of strength training, at ado-
lescence or even earlier, and to verify whether concerns can be grounded scientifically. Current literature does not seem to
have any particular aversion against the practice of strength training by children and adolescents, provided that some
safety rules are followed, like medical clearance, proper instruction from a qualified professional and progressive over-
load. At the same time, several studies provide consistent findings supporting the benefits of repeated, intense physical ef-
forts in young subjects. Improved motor skills and body composition, in terms of increased fat free mass, reduced fat
mass and enhanced bone health, have been extensively documented, especially if sport practice began early, when the sub-
jects were pubescent. It can be therefore concluded that strength training is a relatively safe and healthy practice for chil-
dren and adolescents.
Key words: strength training, weight lifting, adolescents, growth, body composition
Introduction
Modern Western societies imply increasingly seden-
tary life styles and reduced physical exercise. Technologi-
cal progress, limited outdoor activities and economic im-
provement have modified dietary habits and reduced the
amount of exercise performed by children and adoles-
cents1. It is well known that regular moderate intensity
physical activity – such as walking, cycling, or participat-
ing in sports – has significant benefits for health. Accord-
ing to the 2008 guidelines of the European Commission2,
school-aged youth should participate in moderate to vig-
orous daily physical activity for 60 minutes or more. Obe-
sity, sedentary lifestyle and poor cardio-respiratory fit-
ness in childhood and adolescence may increase the risk
of health problems later in life. The teenage years bring
many physical, social and psychological changes for the
individual. From infancy to adulthood, growth, matura-
tion and development occur simultaneously and interact:
growth consists in the increase of the size of the body as a
whole and of its parts, maturation refers to progress to-
wards the biologically mature state and development re-
fers to the acquisition of behavioral competence3.
Changes in body dimensions and composition during
growth and maturation are factors affecting strength
and motor performance4. Some changes in anthropome-
tric traits and strength in a sample of Italian adolescents
studied by Gualdi-Russo and Toselli5arereportedinFig
-
ures 1–4.
The strength and motor performance varies during
childhood and adolescence in relation to biological and
environmental factors. Among biological factors the spe-
cific contribution of maturity status is apparent: the
strength advantage of early-maturing subjects is related
to their larger body size in comparison to late-maturing
ones. These differences are more marked in boys than in
girls. Regular physical activity is an important factor
during growth and maturation, regulating body weight
and, particularly, fatness.
219
Received for publication October 15, 2011
U:\coll-antropolo\coll-antro-(Suppl 2)-2013\Barbieri.vp
9. svibanj 2013 16:26:10
Color profile: Disabled
Composite 150 lpi at 45 degrees
Information on the characteristics of elite young ath-
letes in a variety of sports is rather limited. The evalua-
tion of the maturity status is essential when working
with young athletes because individual differences in the
timing and tempo of biological maturation, particularly
during adolescence, influence body size and composition,
muscular strength and behavior. Inter-individual vari-
ability has important implications for performance, age-
-group competitions and talent identification, selection
and development. Albeit BMI is widely used in surveys of
health and nutritional status, its interpretation in young
adults, especially athletes, as an indicator of fatness
should be taken with caution. Therefore, in kinanthro-
pometry, in order to evaluate the positive effects of physi-
cal activity on body composition, the athlete’s body fat
percentage, fat mass and fat free mass are assessed.
Changes in body composition from early to late adoles-
cence can be summarized as follows: males gain almost
twice as much fat free mass as females, and females gain
about twice as much fat mass as males.
Large fat free mass is important in performances that
require force to be exerted against an object, as in shot
put or weight lifting, but can be a limiting factor in tasks
in which the body must be projected as in vertical jump
or moved across space, as in running. Fat free mass is sig-
nificantly related to strength in male adolescents3.
In sport practice, strength training was usually intro-
duced at the end of the somatic growth, that is when the
athlete was 18 years old or so. In particular, to avoid
weight lifting before and during adolescence was a com-
mon suggestion in many different contexts connected to
physical activity, from commercial gyms to physical edu-
cation courses. This conservative approach has a mainly
anecdotal origin, since usually no scientific evidence is
given in order to support it. Most of the concerns are re-
lated to the possibility of injuries or diminished growth
potential. Still, many of the young athletes who regularly
compete in various sport disciplines begin their training
very early, when they are pubescent or even pre-pubes-
cent. Beside the fact that students begin physical educa-
tion at primary school in many countries, early inception
of sport practice is often suggested in order to take ad-
vantage of the ease and quickness with which children
and adolescents improve their motor control and acquire
new sport skills.
Furthermore, adolescents can be observed while lift-
ing weights during their usual daily activities, outside a
sport or training facility: carrying a schoolbag, a suitcase,
a shopping bag or other items, lifting them from the
floor. Without proper training, they may do it rounding
their back or using any other improper technique, while
the correct one could be learnt under supervision from a
weight lifting instructor, inside a gym.
D. Barbieri and L. Zaccagni: Resistance Training before and during Adolescence, Coll. Antropol. 37 (2013) Suppl. 2: 219–225
220
0
20
40
60
80
100
120
140
160
180
WEIGHT (kg) HEIGHT (cm) BMI (kg/m )
2
12 yrs
13 yrs
14 yrs
Fig. 1. Anthropometric traits in a sample of Italian adolescent
males5by age.
0
20
40
60
80
100
120
140
160
WEIGHT (kg) HEIGHT (cm)
12 yrs
13 yrs
14 yrs
BMI (kg/m )
2
Fig. 2. Anthropometric traits in a sample of Italian adolescent
females5by age.
0
10
20
30
40
50
60
70
80
90
100
kg
RIGHT HAND
GRIP
LEFT HAND
GRIP
LEG
STRENGTH
12 yrs
13 yrs
14 yrs
Fig. 3. Strength values in a sample of Italian adolescent males5
by age.
0
10
20
30
40
50
60
70
80
90
kg
RIGHT HAND
GRIP
LEFT HAND
GRIP
LEG
STRENGTH
12 yrs
13 yrs
14 yrs
Fig. 4. Strength values in a sample of Italian adolescent females5
by age.
U:\coll-antropolo\coll-antro-(Suppl 2)-2013\Barbieri.vp
9. svibanj 2013 16:26:11
Color profile: Disabled
Composite 150 lpi at 45 degrees
It is therefore necessary to evaluate whether the ad-
vice to postpone strength training in general and weight
lifting in particular at the end of adolescence is sound
and can be substantiated scientifically. The main pur-
poses of the present review are the following: to find any
evidence in current literature of benefits or dangers for
the health of the adolescents related to early inception of
strength training, and to compare the relative stress of
this kind of physical activity to other common sport prac-
tices.
Strength Training: Concepts and Objectives
Strength training is a form of physical activity, usu-
ally structured and planned, involving intense efforts
against a resistance. Its main aim is to increase muscular
strength, in order to improve performance, at least in
case a sport is practiced. It is extensively adopted in
power-oriented sports, like sprinting6and soccer7, even if
its benefits are recognized also in endurance sports, like
long distance running8,9 and cross country skiing10,11.In
a non-competitive environment instead, strength train-
ing is adopted for many different purposes. For example,
strength training may be used to improve overall fitness,
increasing muscle hypertrophy and reducing body fat-
ness at the same time. In fact, strength training can be
an effective means to improve body composition12.In
other cases, some individuals may adopt it in order to ac-
complish some professional goal, like achieving the de-
gree of physical fitness which is required in the military
or to join the fire brigade.
To train strength, muscular force is applied against
some kind of resistance. In most cases, especially when
the individual is healthy, resistance is provided by free
weights, like barbells, dumbbells or the athlete’s own
body weight, or by weight machines, like the leg press,
the lat machine etc. This kind of training is usually
adopted in sport conditioning, because the load can be in-
creased progressively according to the athlete’s strength,
which can be considerable. Athletes employ gravity also
in other ways in order to improve their performances,
like in plyometrics or high-impact training, where body
mass is accelerated dropping from a pre-determined
height, according to the athlete’s ability and conditioning
level. This kind of strength training is usually considered
the most dangerous, because the real impact forces ap-
plied to the athlete’s body (bones, muscles, tendons, liga-
ments etc.) are not easily measured, as in weight lifting.
Since force is defined as mass times acceleration, we can
say that weights mainly focus on the first factor, while
plyometrics relies on the second to increase force. None-
theless, also weights can be accelerated, in order to in-
crease force production without adding kilograms, and
advanced plyometrics may imply added weight by means
of weighted belts or vests.
It must be considered, though, that similar strength
training effects can be found in sport practices other
than weight lifting or plyometrics, like sprinting, gym-
nastics and other kinds of power-oriented sports, or team
sports involving leaping and bouncing, like volleyball and
basketball. These types of physical efforts produce great
acceleration, which, applied to the athlete’s body mass,
produce great force. Nonetheless, these intense efforts
are usually practiced by children, even outside a sport
environment, simply while playing with their peers.
Strength training has in important role in rehabilita-
tion after injuries, especially those which involve surgery
and/or a long period of immobilization, in order to re-gain
the physiological muscle hypertrophy and joint range of
motion13–18. In case of injuries to lower limbs, when the
patient is still lying in bed, body weight can be excessive
and not suitable for post-surgery rehabilitation. There-
fore, non-bodyweight bearing exercises can be used, by
means of cables and/or small weights, attached to the an-
kles of the patient, like in leg raises and knee extensions.
Body weight can be excessive also for healthy individ-
uals who have a low relative strength, that is a low
strength-to-body weight ratio. A push up, a pull up or
even a body weight squat can be a demanding task for
people who are too young, elderly, overweight or out of
shape. Free weights or machines can provide a controlled
and adjustable source of resistance. For example, a push
up can be effectively substituted by a bench press, a pull
up by a lat pull down using a lat machine, a body weight
squat by a leg press, involving more or less the same
muscle groups. Weights can be adapted to the individu-
als’ actual strength, which may be relatively low com-
pared to their own body weight.
Other kinds of resistance than weights may be ap-
plied in order to increase muscular strength, like elastic
bands, or friction, as in water or on a steady bike. In fact,
gravity is not necessarily present (e.g. astronauts during
space missions are at risk of losing considerable amounts
of muscle mass19,20) or not fully applicable. Orthopedics
patients may have access to a swimming pool, where the
weight-bearing effort of an injured knee, ankle or hip can
be reduced. At the same time, also competitive swimmers
may use swim paddles to increase the resistance provided
by water.
Exercises are usually performed in sets of several rep-
etitions (i.e. consecutive lifts). If heavy loads are em-
ployed, providing stimulus for maximal strength, then
repetitions are necessarily low in numbers. When the
load is moderate, in order to improve body composition
and cardiovascular fitness, then the overall number of
repetitions can be considerably high. The main training
parameters are intensity and volume. Intensity is given
as percentage of the maximal load which can be lifted for
the prescribed number of repetitions: 1 repetition-maxi-
mum (RM) is the load which can be lifted just once, 10
RM is the load which can be lifted 10 times within one
set. Strength training implies relatively heavy loads, be-
tween 60% and 100% of 1 RM, the so-called »strength
training zone«21. For example, the 90% of 1 RM is a quasi
maximal load, allowing for small volume (i.e. low repeti-
tions). Volume is the total number of repetitions per ex-
ercise. For example, performing 3 sets of 10 repetitions in
one given exercise determines a volume of 30 repetitions.
D. Barbieri and L. Zaccagni: Resistance Training before and during Adolescence, Coll. Antropol. 37 (2013) Suppl. 2: 219–225
221
U:\coll-antropolo\coll-antro-(Suppl 2)-2013\Barbieri.vp
9. svibanj 2013 16:26:11
Color profile: Disabled
Composite 150 lpi at 45 degrees
The most common strength training exercises are
listed in Table 1, with the discipline in which they are
usually practiced, even if in most cases athletes involved
in different sports may use a blend of them. This is espe-
cially true in body building, where the overall balanced
development of muscle mass is of great importance.
Therefore, body builders use most of the listed exercises
(and even more than those), while strength training for
athletes usually comprises a small set of exercises, like
the clean, the squat and the bench press, involving most
skeletal muscles in a coordinated fashion.
Benefits and Risks of Strength Training
for Children and Adolescents
For reasons which have been mainly reported anec-
dotally, strength training, especially if involving weight
lifting, has been considered dangerous for children and
adolescents, and at risk of limiting their growth. How-
ever, the American College of Sports Medicine highlights
that there is no current scientific evidence of the fact
that strength training and weight lifting are inherently
dangerous or can restrain the growth of children and ad-
olescents. Like any other kind of sport practice, there are
some risks which can be considerably diminished follow-
ing a small set of suggestions: proper supervision form
an expert adult, warm up and stretching before lifting,
focus on proper form rather than load, gradual resistance
increases as technique, strength and control improve22.
The American Academy of Pediatrics gives compara-
ble guidelines, implying that strength training can be
safe and effective for children and adolescents, provided
that medical clearance is granted. At the same time, it
discourages them from practicing sports, like Olympic
weightlifting and powerlifting, which involve maximal
lifts23–25.
A similar position has been taken by the National
Strength and Conditioning Association, which is in favor
of supervised and appropriately prescribed strength
training for both pre-adolescents and adolescents26.
In strength training, the gains in muscular strength
are often associated with improvements in body composi-
tion. In a study by Faigenbuam et al.27 a group of boys
and girls aged between 8 and 12 followed a twice-a-week
resistance training program for 8 weeks. After warm up
and stretching, the training group performed the follow-
ing 5 exercises: leg extension, leg curl, bench press, over-
head press and biceps curl. Both training and control
groups continued physical education at school. As ex-
pected, strength gains in the training group were signifi-
cant compared to both pre-training and control. Also im-
provements in body composition were significant:
skinfold thickness decreased of 2.3% on average, com-
pared to an increase of 1.7% in control group. It is inter-
esting to note that upper arm, chest and hip girths did
not change significantly. The only exception was the
thigh girth, which anyway increased relatively less than
control (+2.4% vs. +3.9%).
The volume-intensity schema adopted was the popu-
lar Delorme method: 3 sets of 10 repetitions each, the
first one with 50% of 10 RM, the second one with 75% of
10 RM and the third one with 100% of 10 RM. Delorme
was among the first physicians who realized the impor-
tance of strength training – and weight lifting in particu-
lar – in rehabilitation after injuries28.
A similar pyramiding method was adopted in a study
by Schwingshandl et al.29. Obese children and adoles-
cents were prescribed a diet with caloric restriction. Un-
fortunately, diet alone may reduce both fat and fat free
mass. Subjects were therefore divided into 2 groups:
training and control. After some light aerobics and stre-
tching as a warm up, the training group performed 3 to 4
sets, 10 repetitions each, of the prescribed exercises,
which were chosen to involve all major muscle groups.
The first set was performed using the 50% of 10 RM.
Load was increased progressively in each set, until mus-
cle failure because of fatigue. When the child was able to
complete more than the prescribed 10 repetitions in the
last set, the load was increased in the following training
session. After 12 weeks, weight change was not signifi-
cant in both groups, while the increase in fat free mass
was significantly higher in the training group than in
control, implying that resistance training may have a
positive effect on body composition in fat reduction pro-
grams for obese children and adolescents.
Supervised strength training, involving weight lifting
(bench press, leg extension, lat pull down etc.) and stre-
tching, after an adequate warm up, has proved to be ef-
fective in a group of children, males and females, increas-
ing strength, reducing skinfold thickness, improving
body composition, motor skills and flexibility30.
In a study by Watts et al.31 obese adolescents were in-
volved for 8 weeks in a strength training program con-
sisting in 1 hour of circuit training, 3 times per week, in-
cluding both cycle ergometer and resistance training.
Since the program was primarily designed to treat obe-
sity rather than improving strength, exercise intensity
was kept between 55–70% of pre-training 1 RM. Training
reduced abdominal and trunk fat, thus diminishing car-
diovascular and metabolic risks, and increased strength,
body composition and overall fitness at the same time.
Even if the main purpose of strength training is to in-
crease muscle strength, it seems to have a positive carry
D. Barbieri and L. Zaccagni: Resistance Training before and during Adolescence, Coll. Antropol. 37 (2013) Suppl. 2: 219–225
222
TABLE 1
COMMON STRENGTH TRAINING EXERCISES
Olympic
weightlifting Powerlifting Body
building Body weight
training
Snatch
Clean and
jerk
Squat
Bench press
Deadlift
Overhead
presses
Biceps curls
Leg extensions
Leg curls
Rowers
Push ups
Pull ups
Parallel dips
Body weight
squats
One-leg squats
Sit ups
U:\coll-antropolo\coll-antro-(Suppl 2)-2013\Barbieri.vp
9. svibanj 2013 16:26:11
Color profile: Disabled
Composite 150 lpi at 45 degrees
over also in bone density and therefore it qualifies as an
interesting means for preventing and reducing osteopo-
rosis. This is particularly true for children: if strength
training is adopted early, bone mass gains last longer.
Skeletal exposure to mechanical loading during growth
seems to be an effective strategy to increase bone mass
and density, according to Khan et al.32. In a study by
Fuchs et al.33, high impact training is used to verify its ef-
ficacy in improving skeletal mass in a group of elemen-
tary school children. Bone mineral content, bone area
and bone mineral density were adopted as indices of bone
health. The training protocol consisted in 100 drop
jumps form a 61 cm box, 3 times per week for 7 months,
implying ground reaction forces up to 8 times body
weight. However, the adopted method proved to be safe
and effective in improving the above mentioned parame-
ters at the femoral neck and lumbar spine. Actually, in a
popular sport like gymnastics, impact forces in drop
landings range from 8.2 to 11.6 times body weight, ac-
cording to a study by Ozguven and Berme34.
Even if the authors say that the program could be in-
troduced in physical education classes, its main limita-
tion may be in the fact that high-impact training may re-
sult in an excessive effort for overweight children. Still,
in the training group no injuries occurred during the
whole duration of the study. Actually, selected children
had to be within the 20% of the recommended weight for
height and age. The benefits at the femoral neck per-
sisted even after several months of detraining, when the
same bone health parameters were re-assessed in both
exercise and control group35.
Significant positive effects of impact training on bone
mineral content at the hip was also found by Gunter et
al.36 in a longitudinal study. The benefits of 7 months of
impact training on a group of school children were par-
tially maintained up to 8 years later.
Osteoporosis is a major problem especially for adult
women. Even if considerable improvements in terms of
bone health can be assessed in adults engaging in some
form of strength training, the benefits do not seem to
persist as long as in children or adolescents, suggesting
that early inception of intense physical exercise may be
prescribed for long-lasting improvements. A study by
Winters and Snow37 assessed bone mineral density in a
group of females aged 30–45, before and after a 12 month
training period. The training program included both
high impact and resistance training (squats, lunges and
calf raises). Drop jumps off a box generated ground reac-
tion forces of 4 to 5 times body weight. Intensity was
gradually increased using weighted vests. After the trai-
ning period, exercisers improved their bone mineral den-
sity and strength significantly, with respect to both base-
line (pre-training) and control values. Unfortunately
though, after 6 months of detraining, values decreased
significantly towards baseline values.
A study by Kannus et al.38 evaluated the effects of
playing starting age on bone mineral content of the dom-
inant arm in a group of female tennis players. Athletes
had a significantly higher difference in bone mineral con-
tent between dominant and non-dominant arm com-
pared to control. The difference was 2 to 4 times greater
in individuals who had started playing tennis before or at
menarche, compared to those who had started 15 years
after menarche. Tennis resembles strength training and
may carry over similar effects on the bones since it con-
sists of ballistic and explosive movements, handling a
light implement. Even if the involved masses are small
(ball and racquet), the acceleration produced during the
impact may be very large, producing great force against
the dominant arm.
Similar positive effects on bone mineral density of fe-
male gymnasts were found by Proctor et al.39 in the
whole body and in particular in the upper limbs, without
any significant bilateral differences, which is a major ad-
vantage compared to tennis. Gymnastics exercises, like
pull ups and ring or parallel dips, are often employed in
body weight strength training, for their carry over to up-
per body muscle strength.
Swimming and cycling are among the most popular
sports and bring several health benefits. However, bones
seem to be less directly addressed by these activities, be-
cause of their non-weight-bearing nature, which limits
the loading on the skeleton. A group of well trained ado-
lescent females (track and field athletes, gymnasts and
water polo players) were assessed by Greene et al.40.Al-
though all the selected sports require intense physical
work, gymnastics involves weight-bearing in both the up-
per and lower body, track-and-field (sprints and jumps)
only in the lower body, and water polo has no weight-
-bearing component. Water polo players did not show
greater bone strength or muscle size in the lower leg
compared to controls. On the contrary, gymnasts showed
significantly greater bone strength than non active fe-
males. Also track-and-field athletes displayed greater
bone strength in the lower leg, compared to controls. The
gymnasts showed the greatest musculoskeletal benefits
in the upper body. Despite intense training, water polo
players showed no significant benefits in musculoske-
letal health in the lower body and only limited benefits in
the upper body when compared with non active girls.
Ferry et al.41 investigated bone mineral density in fe-
male adolescent soccer players, swimmers and control
group. Bone mineral density was significantly higher in
soccer players compared with swimmers. In contrast,
swimmers had weaker bones than controls, despite the
fact that female swimmers cannot be considered seden-
tary subjects.
Effects of strength training on connective tissues (lig-
aments and tendons in particular) have not been as
widely assessed as those on bones. However, a recent
study42 has found a positive correlation between resis-
tance training (in particular Olympic weightlifting) and
cruciate ligaments’ cross sectional areas. The authors
conclusions are that the benefits were induced by early
inception of heavy training at the age of puberty.
D. Barbieri and L. Zaccagni: Resistance Training before and during Adolescence, Coll. Antropol. 37 (2013) Suppl. 2: 219–225
223
U:\coll-antropolo\coll-antro-(Suppl 2)-2013\Barbieri.vp
9. svibanj 2013 16:26:12
Color profile: Disabled
Composite 150 lpi at 45 degrees
Discussion and Conclusions
An meaningful distinction should be made between
weight lifting for strength training and Olympic weight-
lifting. The latter implies competitions in which maximal
or even supra-maximal (when the lift fails) loads are em-
ployed, as in powerlifting. In strength training instead,
sub-maximal weights, which can be lifted more than
once, are used. This distinction may account for a differ-
ent risk factor between the aforementioned disciplines.
In general, whenever a maximal effort is required, as in
competitive sport, it is believed that risks tend to be pres-
ent in a higher percentage than in recreational activities.
More specifically, even if strength training may be stren-
uous and intense, if no maximal loads are employed, than
it can be considered a safe and effective form of physical
activity for most individuals, including children and ado-
lescents, provided that proper instruction and supervi-
sion are given.
However, a study by Hamill43 questions the common
belief that resistance training is safer than Olympic
weightlifting, since both appear to be relatively safe ac-
cording to his findings, especially if compared to other
sports. The surveyed subjects were UK students, aged 13
to 16. Practicing both Olympic weightlifting and weight
training had an injury rate of only 0.0012 per 100 partici-
pation hours. Individually, both disciplines scored well
below other popular British sports, like soccer, rugby or
even athletics.
In a study by Risser et al.44 muscle strain, a non-dis-
abling injury, was reported to be the most common acci-
dent among high school American football players prac-
ticing weight lifting as a form of strength training. The
cumulative percentage of injuries among all athletes was
a reasonable 7.6%, corresponding to 0.082 injuries per
person/year. Much higher rates can be found in adoles-
cent45 or amateur46 soccer players. However, the study
did not specify whether injuries were caused by maximal
lifts (i.e. excessive load) or poor form, as it may happen in
a competitive environment, where fatigue and strive for
performance may lead to an excessive demand on the
athlete's physical capabilities.
The topic of growth and strength training could be
further assessed from an endocrine point of view, consid-
ering the relationship between exercise and hormonal re-
sponses. A review by Kraemer and Ratamess47 highlights
the well established finding that resistance training and
growth hormone are positively correlated, but further re-
search is needed in order to verify whether strength
training could induce positive endocrine responses in ad-
olescents.
In conclusion, early inception of strength training, at
adolescence or even earlier, does not seem to imply hig-
her risks than other popular sport disciplines, provided
that the young athletes follow the aforementioned guide-
lines. In particular, supervision by an expert instructor,
focus on proper technique and cautious progression in in-
creasing loads are the most common advices which must
be adhered to. On the positive side, resistance training
has proved to increase basic motor skills, like muscle
strength, coordination and flexibility, but also body com-
position, in terms of improved fat free to fat mass ratio
and increased bone health.
REFERENCES
1. MORANO M, COLELLA D, SDS, 80 (2009) 67. — 2. EU Physical
Activity Guidelines Recommended Policy Actions in Support of Health-
Enhancing Physical Activity (2008), accessed 20.03.2013. Available from:
URL: http://ec.europa.eu/sport/library/doc/c1/pa_guidelines_4th_consoli-
dated_draft_en.pdf. — 3. MALINA RM, Atleticastudi, Suppl. (2006) 1–2.
— 4. MALINA RM, BOUCHARD C, BAR-OR O, Growth, Maturation, and
Physical Activity. Second Edition (Human Kinetics, Champaign, 2004).
— 5. GUALDI RUSSO E, TOSELLI S, Acta Med Auxol, 29 (1997) 13. — 6.
DELECLUSE C, Sports Med, 24 (1997) 147. DOI: 10.2165/00007256-
199724030-00001. — 7. WISLØFF U, CASTAGNA C, HELGERUD J, JO-
NES R, HOFF J, Br J Sports Med, 38 (2004) 285. DOI: 10.1136/bjsm.
2002.002071. — 8. YAMAMOTO LM, LOPEZ RM, KLAU JF, CASA DJ,
KRAEMER WJ, MARESH CM, J Strength Cond Res, 22 (2008) 2036.
DOI: 10.1519/JSC.0b013e318185f2f0. — 9. PAAVOLAINEN L, HÄKKI-
NEN K, HÄMÄLÄINEN I, NUMMELA A, RUSKO H, J Appl Physiol, 86
(1999) 1527. DOI: 10.1063/1.370925. — 10. HOFF J, GRAN A, HELGE-
RUD J, Scand J Med Sci Sports, 12 (2002) 288. DOI: 10.1034/j.1600-0838.
2002.01140.x. — 11. ØSTERÅS H, HELGERUD J, HOFF J, Eur J Appl
Physiol, 88 (2002) 255. DOI: 10.1007/s00421-002-0717-y. — 12. PAOLI A,
PACELLI F, BARGOSSI AM, MARCOLIN G, GUZZINATI S, NERI M,
BIANCO A, PALMA A, J Sports Med Phys Fitness, 50 (2010) 43. — 13.
MARKATOS K, KASETA MK, LALLOS SN, KORRES DS, EFSTATHO-
POULOS N, Eur J Orthop Surg Traumatol, (2012 Sep 22). DOI: 10.1007/
s00590-012-1079-8. — 14. AUGUSTSSON J, Knee Surg Sports Trau-
matol Arthrosc (2012 Aug 17). — 15. WATERS E, J Orthop Sports Phys
Ther, 42 (2012) 326. — 16. LORENZ D, REIMAN M, Int J Sports Phys
Ther, 6 (2011) 27. — 17. AGEBERG E, THOMEÉ R, NEETER C, SIL-
BERNAGEL KG, ROOS EM, Arthritis Rheum, 59 (2008) 1773. DOI: 10.
1002/art.24066. — 18. FITHIAN DC, POWERS CM, KHAN N, Clin
Sports Med, 29 (2010) 283. DOI: 10.1016/j.csm.2009.12.008. — 19.
STEIN TP, Adv Space Biol Med, 7 (1999) 49. DOI: 10.1016/S1569-2574
(08)60007-6. — 20. STEIN TP, GAPRINDASHVILI T, Am J Clin Nutr, 60
(1994) 806S. — 21. SIFF MC, VERKHOSHANSKY YV, Supertraining
(University of Witwatersrand Press, Johannesburgh, S. Africa, 1998). —
22. LAVALLEE M, Current Comment of the American College of Sports
Medicine (2002). — 23. AMERICAN ACADEMY OF PEDIATRICS, Pedi-
atrics 86 (1990) 801. — 24. AMERICAN ACADEMY OF PEDIATRICS,
Pediatrics 107 (2001) 1470. DOI: 10.1542/peds.107.6.1470. — 25. AMER-
ICAN ACADEMY OF PEDIATRICS, Pediatrics 121 (2008) 835. DOI: 10.
1542/peds.2007-3790. — 26. FAIGENBAUM AD, KRAEMER WJ, BLIM-
KIE CJ, JEFFREYS I, MICHELI LJ, NITKA M, ROWLAND TW, J
Strength Cond Res, 23 (2009) S60. DOI: 10.1519/JSC.0b013e31819df407.
— 27. FAIGENBAUM AD, ZAICHKOWSKY LD, WESTCOTT WL, MI-
CHELI LJ, FEHLANDT AF, Pediatric Exercise Science, 5 (1993) 339. —
28. DELORME TL, J Bone Joint Surg, 27 (1945) 645. — 29. SCHWING-
SHANDL J, SUDI K, EIBL B, WALLNER S, BORKENSTEIN M, Arch
Dis Child, 81 (1999) 426. DOI: 10.1136/adc.81.5.426. — 30. LILLEGARD
WA, BROWN EW, WILSON DJ, HENDERSON R, LEWIS E, Pediatric
Rehabilitation 1 (1997) 147. — 31. WATTS K, BEYE P,SIAFARIKASA,
DAVIS EA, JONES TW, O’DRISCOLL G, GREEN DJ, J Am Coll Cardiol,
43 (2004) 1823. DOI: 10.1016/j.jacc.2004.01.032. — 32. KHAN K, MCKAY
HA, HAAPASALO H, BENNELL KL, FORWOOD MR, KANNUS P,
WARK JD, J Sci Med Sport, 3 (2000) 150. DOI: 10.1016/S1440-2440(00)
80077-8. — 33. FUCHS RK, BAUER JJ, SNOW CM, J Bone Miner Res, 16
(2001) 148. DOI: 10.1359/jbmr.2001.16.1.148. — 34. OZGÜVEN HN,
BERME N, J Biomech, 21 (1988) 1061. DOI: 10.1016/0021-9290(88)
90252-7. — 35. FUCHS RK, SNOW CM, J Pediatr, 141 (2002) 357. DOI:
10.1067/mpd.2002.127275. — 36. GUNTER K, BAXTER-JONES AD,
MIRWALD RL, ALMSTEDT H, FUCHS RK, DURSKI S, SNOW C, J
Bone Miner Res, 23 (2008) 986. DOI: 10.1359/jbmr.071201. — 37. WIN-
TERS KM, SNOW CM, J Bone Miner Res, 15 (2000) 2495. DOI: 10.1359/
jbmr.2000.15.12.2495. — 38. KANNUS P, HAAPASALO H, SANKELO M,
D. Barbieri and L. Zaccagni: Resistance Training before and during Adolescence, Coll. Antropol. 37 (2013) Suppl. 2: 219–225
224
U:\coll-antropolo\coll-antro-(Suppl 2)-2013\Barbieri.vp
9. svibanj 2013 16:26:12
Color profile: Disabled
Composite 150 lpi at 45 degrees
SIEVÄNEN H, PASANEN M, HEINONEN A, OJA P, VUORI I, Ann In-
tern Med, 123 (1995) 27. DOI: 10.7326/0003-4819-123-1-199507010-
00003. — 39. PROCTOR KL, ADAMS WC, SHAFFRATH JD, VAN LOAN
MD, Med Sci Sports Exerc, 34 (2002) 1830. DOI: 10.1097/00005768-2002
11000-00021. — 40. GREENE DA, NAUGHTON GA, BRADSHAW E,
MORESI M, DUCHER G, J Bone Miner Metab, 30 (2012) 580. DOI: 10.
1007/s00774-012-0360-6. — 41. FERRY B, DUCLOS M, BURT L, THER-
RE P, LE GALL F, JAFFRÉ C, COURTEIX D, J Bone Miner Metab, 29
(2011) 342. DOI: 10.1007/s00774-010-0226-8. — 42. GRZELAK P, POD-
GORSKI M, STEFANCZYK L, KROCHMALSKI M, DOMZALSKI M, Int
Orthop, 36 (2012) 1715. DOI: 10.1007/s00264-012-1528-3. — 43. HA-
MILL BP, J Strength Cond Res, 8 (1994) 53. — 44. RISSER WL, RISSER
JM, PRESTON D, Am J Dis Child, 144 (1990) 1015. — 45. SCHNEIDER
AS, MAYER HM, GEIßLER U, RUMPF MC, SCHNEIDER C, Sportver-
letz Sportschaden, 27 (2013) 34. — 46. SOUSA P, REBELO A, BRITO J,
Phys Ther Sport, (2012 Oct 13). — 47. KRAEMER WJ, RATAMESS NA,
Sports Med, 35 (2005) 339.
D. Barbieri
Department of Biomedical and Specialty Surgical Sciences, University of Ferrara, Corso Ercole I d’Este 32, Ferrara, Italy
e-mail: davide.barbieri@unife.it
TRENING SNAGE ZA DJECU I ADOLESCENTE: KORISTI I RIZICI
SA@ETAK
Pokazalo se da je tjelesna aktivnost efektivno sredstvo u prevenciji bolesti i pobolj{anju op}eg zdravlja. No, u ve}ini
slu~ajeva se ipak preporu~a laka ili umjerena tjelovje`ba, kako za djecu tako i za odrasle. Nekad se znaju preporu~ati i
intenzivni treninzi snage, poput dizanja utega ili pliometrije, koji se ~ak i kod sporta{a prakticiraju tek pri kraju raz-
vojne dobi. Takve preporuke mogu biti dvojake prirode i cilj je ovog rada procijeniti rizike i koristi ranog uvo|enja
treninga snage, u adolescenciji ili ~ak ranije, kako bismo potvrdili postoji li znanstveno opravdana zabrinutost. Iz aktu-
alne literature se ~ini da ne postoji averzija prema treninzima snage kod djece i adolescenata, ukoliko se primijenjuju
odre|ena sigurnosna pravila poput lije~ni~ke dozvole, to~nih i detaljnih instrukcija od strane kvalificiranog profesio-
nalca i progresivno optere}enje. U isto su vrijeme neke studije utvrdile korist od ponavljaju}eg, intenzivnog tjelesnog
napora kod mladih. Zabilje`ene su pobolj{ane motori~ke sposobnosti, manja koli~ina tjelesne masno}e i zdravije kosti,
pogotovo ako se s treniranjem zapo~ne rano, u pubertetu. Iz navedenog se mo`e zaklju~iti da su treninzi snage sigurni i
zdravi za djecu i adolescente.
D. Barbieri and L. Zaccagni: Resistance Training before and during Adolescence, Coll. Antropol. 37 (2013) Suppl. 2: 219–225
225
U:\coll-antropolo\coll-antro-(Suppl 2)-2013\Barbieri.vp
9. svibanj 2013 16:26:12
Color profile: Disabled
Composite 150 lpi at 45 degrees
... Strength training can be used to improve maximal strength, endurance strength, and power levels [29]. Thus, power training often uses plyometric or 'high impact training', where body mass accelerates when falling from a predetermined height, according to the athlete's ability and fitness level [30]. It is considered that this type of training may present a greater risk of injury, due to the assessment of the impact forces applied to the athlete's body (muscles, bones, tendons and ligaments) are not easily measured, compared to free weights and equipment weight training [16,30]. ...
... Thus, power training often uses plyometric or 'high impact training', where body mass accelerates when falling from a predetermined height, according to the athlete's ability and fitness level [30]. It is considered that this type of training may present a greater risk of injury, due to the assessment of the impact forces applied to the athlete's body (muscles, bones, tendons and ligaments) are not easily measured, compared to free weights and equipment weight training [16,30]. ...
... Nonetheless, it can be used as a training method if it is well programmed, that is, respecting the physical abilities of the practitioners, the knowledge of the execution techniques, as well as the familiarization with the movements. In addition, adequate orientation and constant observation of the trainers are essential for the success of this type of training [16,30,31]. We can still observe movements that are very similar to plyometric training in children's games, as well as in other playful activities. ...
Article
Full-text available
Background Strength training (ST) uses different training methods, such as free weights, body weight, elastic bands or machines to generate resistance force. There is evidence of the ST benefits, however, many professionals have resistance about the applicability of this type of training for children and adolescents, especially at schools. Purpose To describe the possible risks, benefits and pedagogical possibilities of ST in school Physical Education. Methods The search was carried out in the databases PubMed, SciELO, Web of Science and Scholar Google, using followed terms: (i) strength/endurance training, (ii) risks, benefits, (iii) children/adolescents and (iv) physical education. Studies published in the last twenty years in English, Spanish and Portuguese were included. Results There is no evidence to support the hypothesis that ST promotes a growth deficit or a higher injure risk. The ST benefits for this population are extensive, such as an increase in muscular fitness and bone mass, production of IGF-1 growth factor, regulation of body fat, cardiovascular and lipid profile, increase in motor development or sports performance. Physical Education teachers can include ST for students from the age of 6 years and older, through training strategies with their own body weight and simple equipment (e.g., balls and ropes). The focus of ST for prepubertal children should be neuromuscular, that is, in the quality of the movements’ execution. Conclusion ST is positive for children and adolescents development and evidence indicates many benefits. It is recommended that it be included in Physical Education classes through pedagogical activities and adapted strategies.
... Thus, it can be suggested that a wellplanned programme incorporating exercises and physical activity in gymnastics has the potential to positively influence a child's health (Bailey, 2006). With many societies witnessing increased sedentary lifestyles and reduced physical activity, progress seen in technological development, and limited outdoor activities have contributed to the reduction of physical exercise among children and adolescents (Barbieri & Zaccagni, 2013). In the present study, parents of gymnasts felt motivated to keep their children in gymnastics due to the physical, cognitive and socio-emotional benefits experienced when participating in gymnastics. ...
... Dowdell (2013) reports that gymnastics is an excellent vehicle for teaching basic motor skills and promoting health-related fitness in children of all ages. Many studies report that regular moderate intensity exercise and sport presents significant health benefits for young people, and that regular physical activity benefits physical, psychological and social growth, maturation and development, and assists with weight regulation among young people (Barbieri & Zaccagni, 2013). ...
Article
Gymnastics, as a physical activity, presents young people with opportunities to learn physical skills, improve eye-hand coordination, develop gross and fine motor skills, and socially develop through engagement with other young people. An understanding of aerobic and anaerobic physical activities is important to enhance young people’s physical, emotional, cognitive and social development. This study investigated the perceptions of a purposively sampled group of young people in the Western Cape of South Africa about the health benefits of gymnastics participation , and reported findings from the perspectives of registered competitive gymnasts, gymnastics coaches, and parents of gymnasts (total n=34), with specific reference to the domains of physical, cognitive and socio-emotional development. A qualitative approach based on the Process-Person-Context-Time (PPCT) concept, adapted from the bioecological model, was used as the theoretical framework to underpin, analyze and interpret findings of the study. Four key informant interviews were conducted with four coaches, and five focus group discussions were held with gymnasts, parents of gymnasts and gymnastics coaches. Thematic analysis of the participants’ responses indicated the following themes as health benefits and opportunities for children’s development through gymnastics participation: socio-emotional development with respect to positive attitude shifts, respect of peers and coaches, and physical development concerning musculoskeletal growth. Development of strength and flexibility were also found to be positive contributors to child development. Additionally, improvements in cognition which could positively influence children’s academic achievement and the learning of new movement skills, were also attributed to gymnastics participation. The implications of the findings for children’s holistic development was discussed.
... Otro estudio similar (Sgro et al., 2009), recogió después de la intervención de EFP en niños/as obesos, un incremento de la DMO significativa después de 16 semanas del 4,9% y después de 24 semanas de un 6,2% medida a través de DEXA. Por lo tanto, el entrenamiento con ejercicios de fuerza o pesas estimula y mejora la DMO, por lo que Barbieri y Zaccagni (2013) concluyen que un programa de EFP parece tener un efecto positivo a edades tempranas en la DMO y lo califican como un medio interesante para prevenir y reducir la osteoporosis en la adultez. et al., y Vásquez et al., 2013. ...
Article
Full-text available
La inactividad física, cada vez más frecuente entre los niños y las niñas, está asociada a diferentes problemas de salud, entre ellos, la dinapenia pediátrica, caracterizada por bajos niveles de aptitud muscular. Esto suscita la necesidad de implantar programas de Entrenamiento de Fuerza Pediátrico (EFP) para mejorar la salud en esta población. Este trabajo tiene como principal objetivo realizar una revisión sistemática sobre las principales investigaciones que abordaron los efectos de un programa de EFP sobre diferentes parámetros de salud en niños y niñas de 6 a 13 años. Se ha seguido el protocolo PRISMA utilizándose 5 bases de datos (Web of Science, Scopus, Sportdiscus, PubMed y ERIC). Los resultados obtuvieron un total de 587 artículos, de los cuales 13 cumplieron los criterios de inclusión y exclusión. Tras el análisis de los 13 artículos, los resultados muestran que el efecto de las intervenciones de EFP en niños mostró mejoras sustanciales en diferentes parámetros antropométricos (composición corporal, IMC, circunferencia de la cintura y densidad mineral ósea), y en menor medida en variables fisiológicas (presión arterial y perfil lipídico) y psicológicas (autoconcepto y autoestima). Se concluye que los programas de EFP parecen establecerse como un tratamiento no farmacológico adecuado para mejorar determinados parámetros de salud antropométricos, precisando más investigación para determinar el efecto sobre variables fisiológicas y psicológicas.
... In addition, balanced nutrition intake is as well important and resistance training program could be helpful, especially in our case suspected of low muscle mass. Barbieri et al. has reported several benefits can be achieved through strength training in adolescents and children, including improved motor skills, body composition, reduced fat mass and bone health, [19] and accordingly we recommend a resistance exercise program which is 2 days per week, 3 sets of 10 repetitions involving major muscle group with light intensity (50% 1-RM). The interval between each session should be at least 2 days. ...
Article
Full-text available
Background Pituitary stalk interruption syndrome (PSIS) is a rare disease associated with different level of anterior pituitary hormone deficiency resulting with a variety of clinical manifestations which could limit exercise capacity. Cardiopulmonary exercise test (CPET) is valuable in differential diagnosis of exercise intolerance and exercise prescription. Case presentation An 18-year-old male adolescent was diagnosed with PSIS at 4 years old, had undergone growth hormone supplement until puberty, and was referred to rehabilitation department due to exercise intolerance. We arranged pulmonary function test (PFT) and CPET to clarify the cause of limited capacity. The test result provided evidence of moderate functional impairment (54% of predicted maximal oxygen uptake) mainly affected by physical unfitness without significant cardiovascular or pulmonary limitations. Conclusion CPET serves as a valuable tool for diagnostic purpose. Aerobic and resistance exercise training for the patient should be conducted promptly for better prognosis but under safe circumstances, with criteria which could be provided by CPET results.
... These observations are supported by the training effect size in the different categories analyzed, where G1 showed a moderate effect size in contrast to the smaller effect size of the other groups. Studies have shown that early inception of strength training has proved to increase basic motor and specific sport skills, muscle strength and power, coordination, and flexibility (5). In addition, the lack of long-term studies evaluating training-induced gains in muscular fitness throughout childhood and adolescence is scarce, and therefore, our understanding of the sensitivity of the upperbody power, lower-body power, and core muscular endurance to INT is limited. ...
Article
Alonso-Aubin, DA, Picón-Martínez, M, Rebullido, TR, Faigenbaum, AD, Cortell-Tormo, JM, and Chulvi-Medrano, I. Integrative neuromuscular training enhances physical fitness in 6- to 14-year-old rugby players. J Strength Cond Res XX(X): 000-000, 2021-The purpose of this study was to assess the effects of an 8-week integrative neuromuscular training (INT) program on physical fitness measures in young rugby players. A sample of 138 male rugby players (age range, 6-14 years) was divided into 5 age-related groups: group 1 (G1) (n = 20; age, 7.05 (0.58)), group 2 (G2) (n = 27; age, 8.57 (0.49)), group 3 (G3) (n = 31; age, 11.02 (0.56)), group 4 (G4) (n = 33; age, 13.12 (0.58), and group 5 (G5) (n = 27; age, 14.85 (1.53) and additionally into 2 game position groups: forwards (FOR) (n = 69) and backs (BAC) (n = 69). Physical fitness measures included the Functional Movement Screen (FMS), dominant and nondominant hand-to-eye coordination, sprint capacity, core muscular endurance, and lower- and upper-body power. Integrative neuromuscular training (INT) included progressive strength, coordination, and speed exercises performed twice per week for 20 minutes. Following INT, significant improvements in selected age-related groups (p < 0.01) were found in total FMS score G3 (effect size [ES] = 0.47), G4 (ES = 0.88), and G5 (ES = 0.58); dominant hand-to-eye coordination G1 (ES = 1.48), G2 (ES = 0.71), G3 (ES = 0.55), G4 (ES = 1.47), and G5 (ES = 1.15), nondominant hand-to-eye coordination G2 (ES = 0.74), G4 (ES = 1.34), and G5 (ES = 1.09); lower-body power G2 (ES = 0.44), G4 (ES = 0.39), and G5 (ES = 0.43); core muscular endurance G1 (ES = 0.82), G3 (ES = 0.68), and G4 (ES = 1.04); upper-body power G2 (ES = 0.53); and sprint capacity G4 (ES = 0.69). Significant improvements were also found between player's positions for all tests. These findings indicate that a progressive INT program can enhance functional movement abilities and selected physical fitness measures in young rugby players regardless of game position and age.
... Preschool children are in an active neuromuscular developmental process which affects their postural control and muscular strength. In order to support their biological maturation in the best possible way, exercise and varied movement patterns based on fundamental movement skills have been proven to be beneficial, if not mandatory, for healthy childhood development (Barbieri & Zaccagni, 2013;Sibley & Etnier, 2003). Childhood play can not only improve motor skill competence and, in turn, physical performance (Collard et al., 2010), but has also been proven to be a determining factor of long-term fitness, cardiovascular health and participation in recreational as well as elite sports (Lloyd et al., 2015;Vlahov, Baghurst & Mwavita, 2014). ...
Article
Full-text available
Background: Intergenerational exercise possesses the potential to becoming an innovative strategy for promoting physical activity in seniors and children. Although this approach has gained attraction within the last decade, controlled trials on physical and psychosocial effects have not been performed yet. Methods: Sixty-eight healthy preschool children (age: 4.9 y (SD 0.7)) and 47 residential seniors (age: 81.7 y (7.1)) participated in this five-armed intervention study. All participants were assigned to either an intergenerational (IG), peer (PG) or a control group (CON). Children were tested on gross motor skills (TGMD-2), jump performance and handgrip strength. Social-emotional skills questionnaires (KOMPIK) were assessed by kindergarten teachers. Seniors performed the Short Physical Performance Battery (SPPB), including gait speed. Arterial stiffness parameters were also examined. Questionnaires assessing psychosocial wellbeing were filled in with staff. IG and PG received one comparable exercise session a week lasting 45 minutes for 25-weeks. CON received no intervention. Measurements were performed before and after the intervention. Results: In children: IG improved all measured physical parameters. When adjusted for baseline values, large effects were observed in favor of IG compared to CON in TGMD-2 (Cohen's d=0.78 [0.33;1.24]) and in handgrip strength (d = 1.07 [0.63;1.51]). No relevant differences were found in KOMPIK between groups (-0.38<d≤0.14). In seniors: IG showed moderate to very large improvements in all main physical performance (0.61<d≤2.53) and psychosocial parameters (0.89<d≤1.20) compared to CON. Conclusion: IG children showed large benefits in motor skills compared to CON while IG seniors benefit especially in psychosocial wellbeing and functional mobility necessary for everyday life. Intergenerational exercise is comparable and in certain dimensions superior to peer group exercise and a promising strategy to integratively improve mental health as well as physical fitness in preschool children and residential seniors.
... If performed with adequate supervision and/or with the use of stationary machines, strength training may be done safely with no or very few unimportant adverse effects. 2 It is now well documented that the muscle soreness associated with strength training is an important part of the process that leads to the rearrangements and growth of the muscle that underlie (part of) the increased muscle strength. Therefore, the high frequency of adverse effects in the form of muscle soreness as reported in the study by Ryan et al. should not be a cause of worry. ...
Article
This commentary is on the original article by Ryan et al. on pages 1282–1292 of this issue.
Article
Krafttraining für Kinder wird oft kritisch gesehen. Dabei gibt es viele gute Argumente, warum schon die Kleinen damit beginnen sollten: ein Plädoyer.
Article
Primarily definitions regarding of integrative neuromuscular training particularly was explained to reflected especially functional movement in children and adolescents this descriptive review. Subsequently, considered training period related to the development dimension and results of the application that studies was examined. Separate components of integrative neuromuscular training have been evaluated and application recommendations are given to improve performance in children and adolescents. For this reason, we think that it would be correct to know integrative neuromuscular training in order to gain more remarkable practice and experience in children and adolescents when it comes to training contents.
Chapter
Full-text available
La adolescencia es la etapa de la vida (entre los 11 y los 18 años) en la cual se producen numerosos cambios físicos y hormonales (pico de crecimiento, aumento de masa ósea y muscular, aparición de los caracteres sexuales secundarios, etc.) que han servido como motivación para elaborar diferentes estudios que garanticen un desarrollo saludable de los jóvenes. Esos cambios que van sucediéndose en los adolescentes, y las diferentes demandas energéticas y de nutrientes, han hecho necesarias diversas investigaciones a fin de asegurar el aporte nutricional y establecer su relación con el grado de actividad física y para garantizar un buen estado de salud.
Article
Full-text available
In a group of high performance weightlifters increased values of the cruciate ligaments (CLs) cross-sectional areas were observed. The purpose of this research was to investigate if repeated heavy workouts increase the volume of those structures. The knee examinations were performed with an 1,5T MRI system. The area of the anterior cruciate ligament (ACL) and the posterior cruciate ligament (PCL) midsubstance cross-section were evaluated in T1-weighted images with administration of contrast medium in a group of nine athletes. A control group of 19 participants was also examined using the same protocol. Significant differences of the ACL and the PCL midsubstance cross-sectional areas were observed between groups. The area of the CLs' midsubstance and the onset of training were strongly negatively correlated and the PCL cross-sectional area was strongly positively correlated with the duration of training. This research is the first description of the CLs hypertrophy, which is probably caused by heavy training that was started about the age of puberty. The age of training onset seems to have a greater impact on the hypertrophy process than the training duration. Knowledge of the phenomenon of cruciate ligament overgrowth is vital for orthopaedics because, possible changes of the CLs mechanical properties and three-dimensional orientation, may affect the incidence of trauma and reconstruction procedures technique.
Article
Full-text available
The benefits and proposed physiological mechanisms of eccentric exercise have previously been elucidated and eccentric exercise has been used for well over seventy years. Traditionally, eccentric exercise has been used as a regular component of strength training. However, in recent years, eccentric exercise has been used in rehabilitation to manage a host of conditions. Of note, there is evidence in the literature supporting eccentric exercise for the rehabilitation of tendinopathies, muscle strains, and in anterior cruciate ligament (ACL) rehabilitation. The purpose of this Clinical Commentary is to discuss the physiologic mechanism of eccentric exercise as well as to review the literature regarding the utilization of eccentric training during rehabilitation. A secondary purpose of this commentary is to provide the reader with a framework for the implementation of eccentric training during rehabilitation of tendinopathies, muscle strains, and after ACL reconstruction.
Article
Full-text available
Sports training characterized by impacts or weight-bearing activity is well known to induce osteogenic effects on the skeleton. Less is known about the potential effects on bone strength and geometry, especially in female adolescent athletes. The aim of this study was to investigate hip geometry in adolescent soccer players and swimmers compared to normal values that stemmed from a control group. This study included 26 swimmers (SWIM; 15.9 ± 2 years) and 32 soccer players (SOC; 16.2 ± 0.7 years), matched in body height and weight. A group of 15 age-matched controls served for the calculation of hip parameter Z-scores. Body composition and bone mineral density (BMD) were assessed by dual-energy X-ray absorptiometry (DXA). DXA scans were analyzed at the femoral neck by the hip structure analysis (HSA) program to calculate the cross-sectional area (CSA), cortical dimensions (inner endocortical diameter, ED; outer width and thickness, ACT), the centroid (CMP), cross-sectional moment of inertia (CSMI), section modulus (Z), and buckling ratio (BR) at the narrow neck (NN), intertrochanteric (IT), and femoral shaft (FS) sites. Specific BMDs were significantly higher in soccer players compared with swimmers. At all bone sites, every parameter reflecting strength (CSMI, Z, BR) favored soccer players. In contrast, swimmers had hip structural analysis (HSA) Z-scores below the normal values of the controls, thus denoting weaker bone in swimmers. In conclusion, this study suggests an influence of training practice not only on BMD values but also on bone geometry parameters. Sports with high impacts are likely to improve bone strength and bone geometry. Moreover, this study does not support the argument that female swimmers can be considered sedentary subjects regarding bone characteristics.
Article
This paper discusses statistics derived from surveys and competitions. Analyses of previous publications and comparative data from other studies appear to contradict a general view that weight training is safer than weightlifting, when the latter is defined according to the International Weightlifting Federation's rulebook. Both activities appear to be safer than many other sports. The age group considered is largely school age. © 1994 Journal of Applied Sport Science Research. All rights reserved.
Article
The effectiveness of a twice-a-week strength training program on children was evaluated in 14 boys and girls (mean age 10.8 yrs) who participated in a biweekly training program for 8 weeks. Each subject performed three sets of 10 to 15 repetitions on five exercises with intensities ranging between 50 and 100% of a given 10-repetition maximum (RM). All subjects were pre- and posttested on the following measures: 10-RM strength, sit and reach flexibility, vertical jump, seated ball put, resting blood pressure, and body composition parameters. The subjects were compared to a similar group of boys and girls (n = 9; mean age 9.9 yrs) who were randomly selected to serve as controls. Following the training period, the experimental group made greater gains in strength (74.3%) as compared to the control group (13.0%) (p < 0.001), and differences in the sum of seven skinfolds were noted (−2.3% vs. +1.7%, respectively, p < 0.05). Training did not significantly affect other variables. These results suggest that parti...
Article
This study addresses the epidemiology of injuries in adolescent male and female soccer players in Germany. Therefore, the purpose of the study was to analyse the injuries in male and female youth soccer players in Germany. This study was designed as a cross-sectional web-based survey. From March until December 2011 we investigated 1110 soccer players (male n = 841; female n = 269) aged 12 - 19 years (15.0 ± 2.0 years) from 60 clubs in Southern Germany. A total of 664 (79 %) of the 841 boys and 67 (25 %) of the 269 girls reported being injured due to soccer. The total number of injuries was 2373. Respectively the frequency of injury was 2.85 in boys and 7.10 in girls. The lower extremities were affected in 70 % of all reported cases. Strains were the most common injuries in the lower and upper extremities (35 %). The boys reported in 51.5 % of all injuries that the injury was non-contact in nature. In contrast, 52.1 % of the injuries in girls were reported as contact injuries. Similar amounts of injuries were observed in training versus games for both genders. Prevention procedures, such as a thorough warm-up, should be implemented before every game and training to reduce the risk of injury. © Georg Thieme Verlag KG Stuttgart · New York.
Article
Physical activity during childhood is advocated as one strategy for enhancing peak bone mass (bone mineral content [BMC]) as a means to reduce osteoporosis-related fractures. Thus, we investigated the effects of high-intensity jumping on hip and lumbar spine bone mass in children. Eighty-nine prepubescent children between the ages of 5.9 and 9.8 years were randomized into a jumping (n = 25 boys and n = 20 girls) or control group (n = 26 boys and n = 18 girls). Both groups participated in the 7-month exercise intervention during the school day three times per week. The jumping group performed 100, two-footed jumps off 61-cm boxes each session, while the control group performed nonimpact stretching exercises. BMC (g), bone area (BA; cm2), and bone mineral density (BMD; g/cm2) of the left proximal femoral neck and lumbar spine (L1-L4) were assessed by dual-energy X-ray absorptiometry (DXA; Hologic QDR/4500-A). Peak ground reaction forces were calculated across 100, two-footed jumps from a 61-cm box. In addition, anthropometric characteristics (height, weight, and body fat), physical activity, and dietary calcium intake were assessed. At baseline there were no differences between groups for anthropometric characteristics, dietary calcium intake, or bone variables. After 7 months, jumpers and controls had similar increases in height, weight, and body fat. Using repeated measures analysis of covariance (ANCOVA; covariates, initial age and bone values, and changes in height and weight) for BMC, the primary outcome variable, jumpers had significantly greater 7-month changes at the femoral neck and lumbar spine than controls (4.5% and 3.1%, respectively). In repeated measures ANCOVA of secondary outcomes (BMD and BA), BMD at the lumbar spine was significantly greater in jumpers than in controls (2.0%) and approached statistical significance at the femoral neck (1.4%; p = 0.085). For BA, jumpers had significantly greater increases at the femoral neck area than controls (2.9%) but were not different at the spine. Our data indicate that jumping at ground reaction forces of eight times body weight is a safe, effective, and simple method of improving bone mass at the hip and spine in children. This program could be easily incorporated into physical education classes.
Article
Bone health is considered not to benefit from water-based sports because of their weight-supported nature, but available evidence primarily relies on DXA technology. Our purpose was to investigate musculoskeletal health in the upper and lower body in well-trained adolescent female athletes using pQCT and compare these athletes with less-active, age- and sex-matched peers. Bone mineral content, volumetric cortical and trabecular BMD, total and cortical area, and bone strength index were assessed at the distal and proximal tibia and radius in four groups of adolescent females (mean age, 14.9 years) including water polo players (n = 30), gymnasts (n = 25), track-and-field athletes (n = 34), and nonactive controls (n = 28). Water polo players did not show any benefit in bone strength index or muscle size in the lower leg when compared with controls. In contrast, gymnasts showed 60.1 % and 53.4 % greater bone strength index at the distal and proximal tibia, respectively, than nonactive females (p < 0.05). Similarly, track-and-field athletes displayed 33.9 % and 14.7 % greater bone strength index at the distal and proximal tibia, respectively, compared with controls (p < 0.05). In the upper body, water polo players had 31.9 % greater bone strength index at the distal radius, but not the radial shaft, and 15.2 % larger forearm muscle cross-sectional area than controls (p < 0.05). The greatest musculoskeletal benefits in the upper body were found in gymnasts. In conclusion, despite training at an elite level, female water polo players did not show any benefits in musculoskeletal health in the lower leg and only limited benefits in the upper body when compared with nonactive girls.
Article
The purpose of this paper is to outline the final, functional phases of rehabilitation that address exercises, drills, and return-to-play criteria for the sport of basketball, following anterior cruciate ligament (ACL) reconstruction. ACL injuries can be debilitating and affect the quality of life for recreational and elite athletes alike. Tears of the ACL are common in both male and female basketball players, with a higher incidence rate in females. Incidence of a retear to the existing graft or contralateral knee within 5 years of ACL reconstruction with patellar tendon autograft in young (less than 18 to 25 years of age), active basketball players can be as high as 52%. Reducing the number of ACL injuries or reinjury, of which there are an estimated 80 000 per year at an associated cost of over a billion dollars, can have significant potential long-term fiscal and health benefits. Following surgical reconstruction of the ACL, implementing a tailored rehabilitation protocol can ensure a successful return to sport. When searching the literature for such protocols, clinicians may struggle to find specific exercises, drills, and return-to-play criteria for particular sports. The intent of this manuscript is to present such a rehabilitation protocol for basketball.
Article
Osteoporosis is a major, and increasing, public health problem. In this review we examine the evidence that childhood physical activity is an important determinant of bone mineral in adult years, and as such, may help to prevent osteoporosis. Animal studies provide incontrovertible evidence that growing bone has a greater capacity to add new bone to the skeleton than does adult bone. Observational studies in children undertaking routine physical activity and cross-sectional athlete studies in young sportspeople both reveal that activity is positively associated with bone mineral density (BMD). Longitudinal studies in pre- and peripubertal gyrrinasts reveal BMD gains far in excess of those that can be achieved in adulthood. However, such studies permit only limited conclusions as they contain the potential for selection bias and can be confounded by other determinants of bone mineral (e.g. dietary and lifestyle factors). Thus, research comparing inter-individual playing-to-nonplaying arm differences in bone mineral (e.g., in racquet sports) have proven to be extremely useful. These studies suggest that the BMD differences are clearly greater when bone is subjected to mechanical loading prior to the end of puberty and longitudinal growth of the body (in women, before menarche) rather than after it. Tanner stage II and III appears to be the maturational stage when the association between exercise and BMD becomes manifest in most adolescents. Do conclusions drawn from athlete studies apply to the general population? Randomised intervention studies of physical activity and bone mineral accrual in normal children confirm that childhood activity is strongly associated with bone mineral accrual. Furthermore, some retired athlete studies and a detraining study suggest that adolescent bone gain may, at least partly, persist despite reduced adult physical activity. Mechanisms that may, underlie the association between childhood physical activity and bone mineral accrual are outlined. Thus, it appears that physical activity during the most active period of maturity (with respect to longitudinal growth of the body) plays a vital role in optimising peak bone mass and that benefits may extend into adulthood.