Teri McCambridge, MD, FAAPAssistant Professor of Pediatrics

Johns Hopkins School of Medicine

Teri Metcalf McCambridgeA. I have no relevant financial

relationships with the manufacturer's) of any commercial product(s) and/or provider of commercial services discussed in this CME activity.

B. I do not intend to discuss an unapproved/investigative use of a commercial product/device in my presentation.

Case I: 9 year old male football player wants to

begin a strength training program, but his mom has heard he will not demonstrate increases in strength until puberty and that it is dangerous.

What do you advise?

Appropriate age to begin strength training?

Attained the ability to follow rulesAchieve balance and postural control (age 7-8) Proficiency in their sportCommon senseLack of androgenic hormones?Whose idea?What’s the motive?

Richard Santrak

Is it efficacious?Why the controversy?Initial Studies

revealed:No increase in

muscle strength No increase in

muscle cross-sectional area

1983 AAP StatementCommittee on Sports

Medicine“Pre-pubescent boys

(tanner stage 1-2) demonstrate no significant increase in strength or muscle mass because of lack of androgens”Vrijens J Med Sport 1978;

11:152-158

Deficiencies of early researchChildren naturally increase strength as they

grow and mature, must have adequate controls

Studies were short durationStudies evaluated low intensity training

volumes(Sets x repetitions x load)

Overall inadequate studies

Recent Research Demonstrates Significant Gains: Sewall, L, Micheli LJ: J

Pediatric Orthop 1986;6:143-146

Weltman A, et al. Med Sci Sports Exerc 1986; 18:629-638

Faigenbaum, AD, et al. Pediatr Exerc Sci. 1993; 5:339-46.

Faigenbaum, AD,. et al. J Strength and Cond Res 1996; 10(2):109-114

Falk B, et al. Sports Med.1996;22(3):176-186

Faigenbaum AD J Strength Cond Res 2001;15:459-465.

Strength gains between 36%-74.3%

No effect on flexibility

No effect on vertical jump

Mechanism of Strength Gains?Not Muscle Hypertrophy

As measured by CT scanningOccurs in boys and girls equallyStrength gains dependent on increased motor unit:

Activation/recruitmentCoordinationFiring

8 weeks required

Ozmun, J Mikesky A. Med Sci Sports Exerc 1994;26:510-514

Current AAP Policy Statement:2001-”Studies have shown that strength

training, when properly structured with regard to freq, mode, intensity, and duration increases in strength in pre-adolescents without muscle hypertrophy”

2008-”Agree with above and Olympic weight lifting may be safe in closely supervised settings but more research is needed to recommend.”

Is it Safe?Why the concern?Initial NEISS reports

1979 half of 35, 512 weight lifting injuries involved 10-19 year olds

1987 report revealed 8590 children 14 and under were treated in emergency department with weight lifting injuries

1991-1996 20k-26k equipment associated injuries occurring annually

Problems with using this data to determine safety:Does not distinguish between resistance

training and competitive weight liftingInformation is based on patient report of

injuryDoes not distinguish between supervised and

unsupervised injuriesDoes not report if weights were utilized

properly

Is it Safer than some Sports?Study by Hamill

suggests strength training is safer than participation in:SoccerBasketballFootballGeneral play

Hamill B. J Strength Cond Res 1994;8:53-57

Recent literature: CPSC NEISSAccidental weight training Injuries

Myer GD. J Strength Cond Res 2009; 23(7) 2054:2060

Considered Safe:Proper Equipment

Proper Form

Proper SupervisionCertified or Trained

individualRatio of Adult to

Student (1:10)

Health Risks--Stunted Growth?Concerns

Arouse out of studies in Japan

Children performing heavy labor

Resulted in “stunted growth”

Nutritional deficiencies or labor?

Data of well controlled/designed studies no effect on growth or epiphyseal plates

CASE 1Can the 9 year old begin a strength training

program?What’s the reason?Is there supervision?Is it necessary?Is it appropriate?

Case 2:14 year old tanner Stage 3 male basketball

player wants to begin the “clean and jerk” and “snatch”

What is your opinion of these lifts?

Should this be a bigger concern?

Strength Training/Resistance training

“Specialized method of physical conditioning that is used to increase one’s ability to exert or resist force”

Methods?Free weightsWeight Machines

Weight platesHydraulics

Bands/BallsBody weightKettle balls

Other Forms:Brief Discussion:

Competitive Weightlifting (Olympic) Competitive sport that

involves maximum lifting ability

Lifts: Snatch and Clean and Jerk

Minimal Discussion Power Lifting

Competitive sport involving maximum lifts

Dead lift, squats, and bench press

Body Building Competition that

judges muscle size definition, and symmetry

Plyometrics (Stretch-Shortening Cycle)Safe and worthwhile

method of conditioning

Typically includes hops or jumps

Cautious of too many repetitions

The “Power Clean”

“Clean and Jerk”

The “Snatch”

“Dead Lift”

Is Olympic Weightlifting Safe?Data suggests

safety in well supervised settings

Study at the USA Weightlifting Development Center

Byrd R, Pierce K, et al. Sports Biomech 2003;Jan 2(1): 133-40

The AAP’S Policy (2008)Safe in Well controlled studies, emphasizing

proper techniqueDo not yet recommend for general

populationConcerns regarding improper technique and

injury riskImpetus for childhood involvement?

What’s Really HappeningSurvey of HS S&C

coaches38 of 128

Responded 37 of 38 use

Olympic –Style lifting

Duehring MD, J Strength Cond Res 2009; 23(8)2188-2203

Severe Injuries associated with improper Olympic lifting

Bilateral Distal Radial and Ulnar Fractures

Disc HerniationSpondylolysis and

SpondylolisthesisASIS pelvic

avulsion fracture Scaphoid fractureDeath

CASE 2

What’s the difference between strength training and competitive weightlifting?

Why the distinction when recommending children’s participation?

Case 3: A 12 year old female soccer players’ parents

wants to know if strength training can: Prevent an ACL tear?

Improve sports performance in the pre-adolescent?

Provide permanent strength gains once a program is completed?

Injury Prevention with Strength Training?Less Shoulder pain in Adolescent Swimmers

Dominquez, Swimming Medicine IV 1978: 105-109

Decreased incidence and severity of knee injury with preseason trainingCahill B, Griffith E. Am J Sport Med 1978; 6:180-184

ACL prevention with Plyometric jump training program

Hewett, TE, et al. Am J Sport Med 1999; 27:699

More Evidence to follow?

Benefits? Anaerobic Power? 30 Prepubescent male athletes 12 week strength training with free weights

and machines. 3x/weekOutcome variables: vertical jump, 40 yd dash,

and Wingate testResults: Vertical jump improved, but no other

measures of anaerobic power

Hetzler, RK, Coop D, et al. J Strength Cond. Res. 1997; 11(3):174-181

Sports Performance?Inconclusive evidence

Evidence for improved vertical jump long jump sprint speed Medicine ball toss

Translation into improved performance is inconclusive

Limited evidence improvement

Christou M. (soccer) J Strength Cond Res 2006 20(4), 783-791

Hoffman JR (football) J strength Cond Res 2005; 19(4):810-815

Faigenbaum A. Phys Edu 2006; 63: 160-67.

Strength Training and DetrainingRecommend

Frequency in children2x/week training

DetrainingLoss of strength

about 3% week

Despite athletic participation

Faigenbaum AD, et al. Faigenbaum AD, et al. Res Quarterly Exercise Res Quarterly Exercise Sport, 2002; 73(4): Sport, 2002; 73(4): 416-424.416-424.

Faigenbaum, AD, et al. J Strength and Cond Res 1996; 10(2):109-114

CASE 3

Strength training is not the “end-all-be-all” for sports

Just one component of various training methods

“Prehabilitation” strengthening may have some promise

Performance benefit lacking at this time

Case 4 A 15 year old, with a past medical history of

Childhood leukemia, wants to begin a strength training program—Is there any evaluation required prior to participation?

Athletes requiring clearance prior to participationUncontrolled severe hypertensionPrevious treatment with anthracycline

chemotherapeutic agentsUncontrolled seizure disorderUnderlying neuromuscular disorder

(Cerebral Palsy, etc.)

Cardiology consultation recommended if history of:Hypertrophic

CardiomyopathyModerate-Severe

pulmonary hypertension

Uncontrolled Hypertension

Marfan’s Syndrome with a dilated aorta

Aortic Root dilatation in Elite Strength Trained athletes100 Elite Strength trained athletes

Age mean 22.1 + 3.6 years128 healthy age and height matched control Results Aortic root diameters were

significantly greater in all 4 locations of measurement, with progressive enlargement noted based on duration of high intensity lifting.

Am J Cardiology 2007: 100:528-530

Past Medical History:Childhood Leukemia/OncologyPatient’s treated with high dose (500

mg/M2)anthracycline therapy are at risk for acute cardiac decompensation with initiation of weight training

Cardiology/Oncology input required prior to program initiation

Steinherz, Laurel, et al. Cardiac Toxicity 4 to 20 years after completing anthracycline therapyJama 1991; 266 (12): 1672-1677.

CASE 4

Usual preparticipation guidelines existBe aware of new recommendations, such as

for young cancer survivors

Case 5. The parents of a 14 year old want to enroll

their child in a strength training program. They bring in a list of questions including:Guidance on a proper strength training

programHow to evaluate a personal trainer’s

credentialsList of respected sports training facility in your

area

Initiating a Weight Training Program

What you

need to know!

Guidelines have been established by The AAP, AOSSM, and NSCA

General Recommendations(program)10 minutes dynamic warm-up and cool

downProgram should include 1-3 sets of 6-15

reps of 6-8 exercisesInclude all muscle groups and a full ROM

at each jointFocus on technique and proper formRecommend 2-3 non-consecutive training

sessions/wk for 20-30 minIncrease resistance gradually Program varied over time

Faigenbaum AD. Clinics in Sport Med; 19 (4): 2000

.

Examples of exercises to incorporate into a beginning program

Single joint Leg extension

Multi-joint Squats

PlyometricsSquat jumps,

medicine ball chest passes

Core strengtheningSit-ups, back

extensions

Means of progressing a programIncrease the resistance

Generally 5-10% increase in training load

Increase repetitions

Increase number of sets

Recommendations for Parents evaluating a programQualifications of InstructorStudent : Teacher ratioModes of strength training that will be

utilizedEvaluate weight stack increments (1-5 pounds

in children)Weight machine sizesWill 1 weight rep max be usedPerformance of Olympic or power lifts

Special Recommendations forYouth Strength trainingConsider decreasing training volume and

intensity during rapid growthEmphasize flexibility Stress importance of proper lifting

techniques not amount of weight liftedControlled movementsProper breathing

Recommend against competitive weight lifting, power lifting, and body building until skeletally mature

Evaluating Strength Training CredentialsIs the program NCCA certified?Do they require re-certification and CEU’S?Are there minimum requirements?Is the exam proctored and does it have a

practicum? How long have they been certified?

What Credentials are recommended for Strength and Conditioning Specialists?National Strength

and Conditioning AssociationCSCSNSCA-CPT

American Council on Exercise

American College of Sports Medicine (ACSM)

ACSM Health Fitness Instructor

ACSM Exercise Specialist

National programs for youth strength training?Velocity sports performance

http://www.velocitysp.com/

Competitive Athletic Training Zone (CATZ) http://www.catzsports.com/

Case 6:Are there special patient populations in your

practice that could benefit from a strength training exercise prescription?Overweight or “At Risk” for overweight

patientsCerebral PalsyOsteoporosis or Osteopenia

Benefits: Particular benefit for the overweight child?Cardiovascular

fitnessBody compositionBone mineral

densityBlood lipid profileMental Health

AnxietySelf-concept

Benefits: Cerebral PalsyIncreased strength Improved overall functionImproved Mental Well-being

Blundell S. Clin Rehab 2003;17: 48-57

McBurney H. Dev Med Child Neuro 2003; 45:658-663

Benefits: Bone mineral densityPrevention of OsteoporosisAdolescent bone is responsive to the

osteogenic stimulus of heavy resistance training

Bone density of junior Olympic weight lifters was greater than age matched controls and normal adult bone density

Conroy BP. Med Sci Sport Exerc. 1993;25:1103-9

Why Are Kids Strength Training?Fun?Improve

Performance?Parental

Pressures?Will they burn out?Should they be

spending more time “playing” sports?

AAP Recommendations:Prevention Overuse and BurnoutLimit activity to 1

sporting activity a maximum of 5 days a week.

One day off from any organized physical activity per week

2 to 3 months off per year from their sport

Food for Thought! 0.2-0.5 % of high

school athletes ever make it to the professionals.

Variety is the spice of life

References:AAP COSMF Policy Statement. Strength

training by Children and Adolescents Pediatrics 2008 121(4):835-40.

AAP Overuse Injuries, Overtraining, and burnout in Child and Adolescent Athletes. Pediatrics 2007; 119(6):1242-1245.

Youth Resistance Training: Position Statement Paper and Literature Review. J Strength Cond Res 2009 23(4):1-20.

Thank you!