Teri McCambridge, MD, FAAP Assistant Professor of Pediatrics Johns Hopkins School of Medicine.
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Teri McCambridge, MD, FAAP Assistant Professor of Pediatrics Johns Hopkins School of Medicine Teri Metcalf McCambridge A. 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 rules Achieve balance and postural control (age 7-8) Proficiency in their sport Common sense Lack 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 crosssectional area Vrijens J Med Sport 1978; 11:152-158 1983 AAP Statement Committee on Sports Medicine “Pre-pubescent boys (tanner stage 1-2) demonstrate no significant increase in strength or muscle mass because of lack of androgens” Deficiencies of early research Children naturally increase strength as they grow and mature, must have adequate controls Studies were short duration Studies 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 scanning Occurs in boys and girls equally Strength gains dependent on increased motor unit: Activation/recruitment Coordination Firing 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 lifting Information is based on patient report of injury Does not distinguish between supervised and unsupervised injuries Does not report if weights were utilized properly Is it Safer than some Sports? Study by Hamill suggests strength training is safer than participation in: Soccer Basketball Football General play Hamill B. J Strength Cond Res 1994;8:53-57 Recent literature: CPSC NEISS Accidental weight training Injuries Myer GD. J Strength Cond Res 2009; 23(7) 2054:2060 Considered Safe: Proper Equipment Proper Form Proper Supervision Certified or Trained individual Ratio 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 1 Can 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 weights Weight Machines Weight plates Hydraulics Bands/Balls Body weight Kettle balls Other Forms: Brief Discussion: Competitive Weightlifting (Olympic) Minimal Discussion Power Lifting Competitive sport that involves maximum lifting ability Lifts: Snatch and Clean and Jerk 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 technique Do not yet recommend for general population Concerns regarding improper technique and injury risk Impetus for childhood involvement? What’s Really Happening Survey of HS S&C coaches 38 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 Herniation Spondylolysis and Spondylolisthesis ASIS pelvic avulsion fracture Scaphoid fracture Death 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 training Cahill 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/week Outcome variables: vertical jump, 40 yd dash, and Wingate test Results: 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 Hoffman JR (football) J strength Cond Res 2005; 19(4):810-815 Faigenbaum A. Phys Edu 2006; 63: 160-67. Christou M. (soccer) J Strength Cond Res 2006 20(4), 783-791 Strength Training and Detraining Recommend Frequency in children 2x/week training Detraining Loss of strength about 3% week Faigenbaum AD, et al. Res Quarterly Exercise Sport, 2002; 73(4): 416-424. Despite athletic participation 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 participation Uncontrolled severe hypertension Previous treatment with anthracycline chemotherapeutic agents Uncontrolled seizure disorder Underlying neuromuscular disorder (Cerebral Palsy, etc.) Cardiology consultation recommended if history of: Hypertrophic Cardiomyopathy Moderate-Severe pulmonary hypertension Uncontrolled Hypertension Marfan’s Syndrome with a dilated aorta Aortic Root dilatation in Elite Strength Trained athletes 100 Elite Strength trained athletes Age mean 22.1 + 3.6 years 128 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/Oncology Patient’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 therapy Jama 1991; 266 (12): 1672-1677. CASE 4 Usual preparticipation guidelines exist Be 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 program How to evaluate a personal trainer’s credentials List 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 down Program should include 1-3 sets of 6-15 reps of 6-8 exercises Include all muscle groups and a full ROM at each joint Focus on technique and proper form Recommend 2-3 non-consecutive training sessions/wk for 20-30 min Increase 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 Plyometrics Squat jumps, medicine ball chest passes Core strengthening Sit-ups, back extensions Means of progressing a program Increase the resistance Generally 5-10% increase in training load Increase repetitions Increase number of sets Recommendations for Parents evaluating a program Qualifications of Instructor Student : Teacher ratio Modes of strength training that will be utilized Evaluate weight stack increments (1-5 pounds in children) Weight machine sizes Will 1 weight rep max be used Performance of Olympic or power lifts Special Recommendations for Youth Strength training Consider decreasing training volume and intensity during rapid growth Emphasize flexibility Stress importance of proper lifting techniques not amount of weight lifted Controlled movements Proper breathing Recommend against competitive weight lifting, power lifting, and body building until skeletally mature Evaluating Strength Training Credentials Is 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 Association American College of Sports Medicine (ACSM) CSCS ACSM Health Fitness NSCA-CPT Instructor ACSM Exercise Specialist American Council on Exercise 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 patients Cerebral Palsy Osteoporosis or Osteopenia Benefits: Particular benefit for the overweight child? Cardiovascular fitness Body composition Bone mineral density Blood lipid profile Mental Health Anxiety Self-concept Benefits: Cerebral Palsy Increased strength Improved overall function Improved Mental Well-being Blundell S. Clin Rehab 2003;17: 48-57 McBurney H. Dev Med Child Neuro 2003; 45:658-663 Benefits: Bone mineral density Prevention of Osteoporosis Adolescent 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 Burnout Limit 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):83540. 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!