Week 6 - Exercise in Special Populations Flashcards
Process of conception
Conception occurs when a sperm penetrates an ovum
- 23 chromosomes of the sperm + 23 chromosomes of the ovum = zygote
- 23rd pair is sex
- 22 pairs autosomal
Sex is determined by the sperm
XX = female; XY = male
The rate of multiple births has doubled in Canada since the 1990s
3/1000 births are multiples
- Identical vs. fraternal
– Identical ⅓ — identical genes, single egg and sperm
– Fraternal ⅔ — 50% shared genes; regular siblings; 2 sperm and ova - Increased maternal age
- Assisted Human Reproduction
– Fertility drugs
– Cryopreservation — IVF labs
– Artificial insemination
Pregnancy
a physical condition in which a woman’s body is nurturing a developing embryo or fetus
Prenatal Development
Prenatal development, or gestation, is the process that transforms a zygote into a newborn
length of pregnancy
40 weeks (±2) or 10 months
1st trimester
weeks 1-12
2nd trimester
weeks 13-24
3rd trimester
weeks 25+
Milestones of prenatal development
No period in human lifespan where more changes occur at a faster rate than the prenatal period
Germinal Stage
first two weeks, including conception to implantation
Conception
Day 1
- Sperm and ovum unite, forming a zygote containing genetic instructions for the development of a new and unique human being.
Implantation
Days 10-14
- The zygote burrows into the lining of the uterus. Specialized cells that will become the placenta, umbilical cord, and embryo are already formed.
NOTE: mom and baby blood NEVER mix due to function of placenta
Embryonic Stage
Weeks 3-8
includes organogenesis
Organogenesis
All the embryo’s organ systems form during the six-week period following implantation
Weeks 9-12
Fingerprints; grasping reflex; facial expressions; swallowing and rhythmic “breathing” of amniotic fluid; urination; genitalia alternating periods of physical activity and rest
Weeks 13-16
Hair follicles; responses to mother’s voice and loud noises; 8 to 12 centimetres long, crown to rump; weighs 25 to 100g
Weeks 17-20
Fetal movements felt by mother; heartbeat detectable with stethoscope; lanugo (hair) covers body; eyes respond to light introduced into the womb; eyebrows; fingernails; 13-17 cm long, crown to rump; weights 140-300g
Weeks 21-24
Vernix (oily substance) protects skin; lungs produce surfactant (vital to respiratory function); viability becomes possible, although most born now do not survive
Weeks 25-28
Recognition of mother’s voice; regular periods of rest and activity; 35-38 cm long, crown to heel; weighs 660-1000g; good chance of survival if born now
Weeks 29-32
Very rapid growth; antibodies acquired from mother; fat deposited under skin; 39-43 cm long, crown to heel; weighs 1.2-1.7 kg; excellent chance of cervical if born now
Weeks 33-36
Movement to head-down position for birth; lungs mature; approx. 44-48 cm long, crown to heel; weighs about 1.9-2.6 kg; virtually 100% chance of survival if born now
Weeks 37+
Full-term status; about 49 cm long, crown to heel; weighs about 3kg
Low birth weight (LBW)
- Newborn weight below 2500g
- Preterm most common
- Small-for-date / small for gestational age
Below 1500g
significantly higher rates of long-term problems;
Smaller size
Lower intelligence scores
Problems in school
Large for Gestational Age
newborn weight above 4000g at birth (9lb, 15 oz)
macrosomic
Implications of LGA
Increased likelihood of chronic disease later in life;
Obesity
CVD
Diabetes
Metabolic syndrome
What is stronger predictor of infant body fat at birth:
Timing of excessive maternal weight gain OR total maternal weight gain?
Timing of excessive maternal weight gain, specifically during the first half of pregnancy, is a stronger predictor of infant body fat at birth than total maternal weight gain!!
Maternal Changes During Pregnancy: Milestones
Musculoskeletal Changes
- Increase force on joints
– From increase in body mass; esp hips and knees. - Increased force may cause discomfort to normal joints and increase damage to arthritic or previously injured joints.
- Ligament laxity → Relaxin → more prone to injuries
- Balance
- Lumbar lordosis → deep curve in lower back
Chronic Hypertension
If high blood pressure develops before 20 weeks of pregnancy or lasts more than 12 weeks after delivery, it’s known as chronic hypertension
Gestational Hypertension
If high blood pressure develops after 20 weeks of pregnancy, it’s known as gestational hypertension
How many women develop gestational hypertension?
~9%
Preeclampsia
a serious condition characterized by increased blood pressure and protein in the urine after 20 weeks of pregnancy (~4%).
- chronic hypertension or gestational hypertension can lead to preeclampsia
- Left untreated, preeclampsia can lead to serious — even fatal — complications for both mother and baby
Risk Factors for Hypertensive Disorders/PE
- Obesity
- Sedentary lifestyle
- History of diabetes
- Family history of hypertension
Gestational Diabetes Mellitus
A condition in which women without previously diagnosed diabetes exhibit high blood glucose levels during pregnancy
- Babies born to mothers with GDM are at increased risk of complications, LGA, primarily growth abnormalities and chemical imbalances such as low blood sugar
How many women develop gestational diabetes?
~10%
Risk Factors for Gestational Diabetes
- Maternal age*
- Family history of diabetes*
- Ethnicity*
- Sedentary lifestyle
- Previous GDM
- Obesity and GDM closely linked
Gestational Weight Gain
Excess gestational weight gain (EGWG) and postpartum weight retention (PPWR) are two primary lifestyle contributors to obesity among women of childbearing age.
- Increased risk of birth complication, cesarean delivery, LGA, SGA, infants.
- If a person is not active during pre-pregnancy, pregnancy and even postpartum is a good time to implement PA routine
how many women are at least 5 kg (11 lbs) heavier 6-18 months PP than before pregnancy?
15-20%
Average pregnancy-related weight gain
1.5-7 lbs (0.5- 3.0 kg)
Appropriate Weight Gain
Where does the weight go?
History of PA during Pregnancy
Prior to 1985 Exercise Guidelines for Pregnant people did not exist – told to REST!!
1985
ACOG suggested heart rate should not go above 140bpm
1994
ACOG Ignored heart rate; Replaced with “common sense” guidelines
2002
ACOG Ignored heart rate; Replaced with exercise on all days of week!!
PARmed-X for Pregnancy
(Physical activity readiness, medical pre-screening & exercise prescription) - written for physician/midwife or health care professional to increase communication
CSEP & Health Canada (1996; Revised 2002; 2011; 2013)
2003
Canadian guidelines for active living during pregnancy – Joint SOGC/CSEP Clinical Practice Guideline
Canadian Physical Activity Guidelines during Pregnancy
2019
- Published article in BJSM → Journal of Sport and Exercise Medicine
Get Active Pregnancy Questionnaire (replaces PARmed-X)
2020
Medical Screening
Get Active Pregnancy Questionnaire → 2 page document
Prescreening tool → if they answer yes to any Q they need to take followup questionnaire to their healthcare provider to go over some things
Canadian Physical Activity Guidelines during Pregnancy Recommendation 1
_all_ women without contraindication should be physically active throughout pregnancy
- Strong recommendation, moderate-quality evidence
- subgroups:
– Women who were previously inactive.
– Women diagnosed with gestational diabetes mellitus.
– Women categorised as overweight or obese (pre-pregnancy body mass index ≥25 kg/m2)
Canadian Physical Activity Guidelines during Pregnancy Recommendation 2
pregnant women should accumulate at least 150 minutes of moderate-intensity physical activity each week to achieve clinically meaningful health benefits and reductions in pregnancy complications
Canadian Physical Activity Guidelines during Pregnancy Recommendation 3
physical activity should be accumulated over a minimum of three days per week; however, being active every day is encouraged
Canadian Physical Activity Guidelines during Pregnancy Recommendation 4
pregnant women should incorporate a variety of aerobic and resistance training activities to achieve greater benefits
- adding yoga and/or gentle stretching may also be beneficial
Canadian Physical Activity Guidelines during Pregnancy Recommendation 5
pelvic floor muscle training (ie. kegel exercises) may be performed on a daily basis to reduce the risk of urinary incontinence
- instruction in proper technique is recommended to obtain optimal benefits
Canadian Physical Activity Guidelines during Pregnancy Recommendation 6
pregnant women who experience light-headedness, nausea or feel unwell when they exercise flat on their back should modify their exercise position to avoid the supine position
Moderate Intensity PA
Intense enough to increase HR; a person can talk but not sing during activity
e.g. brisk walking, water aerobics, stationary cycling (moderate effort), resistance training, carrying moderate loads, household chores (e.g. gardening, washing windows).
3 Ways to Monitor Intensity
Maternal Heart rate – pregnancy-specific target heart rate zones
“Talk test” – maintain a conversation during PA and should reduce intensity if not possible
Rate of Perceived Exertion (Borg Scale ~7/10 effort)
Heart Rate Ranges for Pregnant Women
Maternal Health Benefits of Exercise
_most complications can be fixed with exercise!_
- decreased risk of pre-eclampsia
- gestational hypertension
- gestational diabetes
- caesarean section
- instrumental delivery
- urinary incontinence
- excessive gestational weight gain
- improved blood glucose
- decreased total gestational weight gain
- decreased severity of depressive symptoms
- decreased severity lumbopelvic pain
Newborn Health Benefits of Maternal Exercise
Fewer newborn complications ie. large for gestational age
Contradindications
absolute = stop
relative = cautious
Multiple Pregnancies & Contraindications
BOTH absolute and relative contraindications
Absolute Contraindications
- ruptured membranes, premature labour
- unexplained persistent vaginal bleeding
- placenta praevia after 28 weeks’ gestation
- pre-eclampsia
- incompetent cervix
- intrauterine growth restriction
- high-order multiple pregnancy (ie. triplets)
- uncontrolled type I diabetes, uncontrolled hypertension, or uncontrolled thyroid disease
- other serious cardiovascular, respiratory or systemic disorder
Relative Contraindications
- recurrent pregnancy loss
- history of spontaneous preterm birth
- gestational hypertension
- symptomatic anaemia
- malnutrition
- eating disorder
- twin pregnancy after the 28th week
- mild/moderate cardiovascular or respiratory disease
- other significant medical conditions
Safety Precautions
- Avoid physical activity in excessive heat, especially with high humidity.
- Avoid activities which involve physical contact or danger of falling. (eg real bike vs stationary)
- Avoid scuba diving.
- Lowlander women (living below 2500 m) should avoid physical activity at high altitude (>2500 m).
- Those considering athletic competition or exercising significantly above the recommended guidelines should seek supervision from an obstetric care provider.
- Maintain adequate nutrition and hydration.
- Know the reasons to stop physical activity and consult a qualified healthcare provider immediately if they occur.
Summary
- Represents a foundational shift in our view of PA
- From recommended behaviour to improve quality of life
- To a specific prescription for PA to reduce pregnancy complications and optimize health for two generations.
- Important to implement into clinical practice for lifelong benefits for mother and child
- Recall → the egg that formed you was made when your grandmother was preg. with mom
_Fewer than 15% of pregnant women meet the guidelines of 150 minutes of moderate PA per week!_
Impact of Birth
- Birth can cause acute trauma to the pelvic floor and surrounding tissues.
- Delivery by Caesarean section may occur if the fetus is in distress, labour fails to progress, a fetus is too large, or the mother has certain health conditions.
How long does medical follow-up typically occur for?
6 weeks postpartum
Caesarean birth recovery can last up to…
12 weeks or more
Vaginal birth recovery lasts…
a month or so
Postpartum PA Considerations
Musculoskeletal complications
- Sciatic nerve, upper body nerves
- Separation of sacroiliac joint
- Separation of pubic symphysis
- Diastasic Recti (rectus abdominus separation)
- Pelvic Floor Dysfunction
timeline to return to regular exercise program depends on these as well as type of birth and type of pregnancy they had
Postpartum Weight Retention
According to the Institute of Medicine (IOM):
_50% will retain more than 10lbs (4.5kg) at 6 months postpartum._
- 25% will retain more than 20lbs (9kg) at 6 months postpartum, leading to PPWR.
– Perpetuates the cycle of obesity
Physical Activity and Breastfeeding
- Breast milk _does not differ_ in volume or composition: energy, protein, lactose, lipid or lactic acid composition.
- Physically active women can exercise for long periods of time without affecting lactation performance if caloric intake adequate to meet higher energy needs.
- Mothers who exclusively breastfeed lose 86% weight in the first 6-month and retained 14% at 12-months PP
Postpartum Depression
- Postpartum Depression (“baby blues” during first few weeks)
- Dramatic and rapid drop/change in hormones after delivery
- Increased susceptibility to clinically defined mood disorders (depression)
Diastasis Recti
A condition in which both rectus abdominus muscles disintegrate to the sides, this being accompanied by the extension of the linea alba tissue and bulging of the abdominal wall
Pelvic Floor Dysfunction
A condition affecting 300,000 - 400,000 American women per year Symptoms include;
- Urinary incontinence, “Leaking” urine at any time
- Uterine prolapse
- Nagging pain → Pelvic area, low back, or hips
- Painful sex
American College of Sports Medicine
“Physical activity can be resumed after pregnancy but should be done so gradually because of normal deconditioning in the initial postpartum period.
**Gradual exercise may begin ~4-6 weeks after vaginal delivery or 8-10 weeks (with medical clearance) after cesarean section delivery.” **
Exercise Interventions
Postpartum exercise programs should be;
- Group-based
- Instructor-led
- Include infants OR provide childcare
- Improve pelvic health
- Consider all stages of postpartum
Canadian 24-Hour Movement Guidelines for Children and Youth
An integration of physical activity, sedentary behaviour, and sleep
Healthy 24 Hours Includes:
1) SWEAT - moderate-to-vigorous PA
2) STEP - light PA
3) SLEEP
4) SIT - sedentary behaviour
SWEAT
- Accumulation of at least 60 min per day involving a variety of aerobic activities
- Vigorous PA, muscle and bone strengthening activities incorporated 3 days per week
STEP
- Several hours of a variety of structures and unstructured light PA
SLEEP
- Uninterrupted 9-11 hours per night ages 5-13
- 8-10 hours for those 14-17 years old
- Consistent bed and wake-up times
SIT
- No more than 2 hours per day of recreational screen time; limited sitting for extended periods
INFANTS MOVE
Interactive floor-based play—more is better
Not yet mobile, at least 30 minutes of tummy time spread throughout the day while awake
INFANTS SLEEP
14-17 hours (0-3 months old)
12-16 hours (4-11 months old)
Of good quality sleep, including naps
INFANTS SIT
Not being restrained for more than 1 hour at a time (ie. in a stroller or a high chair)
Screen time not recommended
When sedentary, engaging in pursuits such as reading and storytelling with a caregiver is encouraged
TODDLERS MOVE
Least 180 minutes spent in a variety of physical activities at any intensity, including energetic play, spread throughout the day—more is better
TODDLERS SLEEP
11-14 hours, good quality, including naps, with consistent bedtimes and wake-up times
TODDLERS SIT
Not being restrained for more than 1 hour at a time (ie. in a stroller or a high chair) or sitting for extended periods
Younger than 2, sedentary time not recommended
Aged 2, screen time no more than 1 hour—less is better
When sedentary, engaging in pursuits such as reading and storytelling with a caregiver is encouraged
PRESCHOOLERS MOVE
At least 180 minutes spent in a variety of physical activities spread throughout the day, of which 60 minutes is energetic play—more is better
PRESCHOOLERS SLEEP
10-13 hours, good quality, including naps, with consistent bedtimes and wake-up times
PRESCHOOLERS SIT
Not being restrained for more than 1 hour at a time (ie. in a stroller or a high chair) or sitting for extended periods
Screen time should be no more than 1 hour—less is better
When sedentary, engaging in pursuits such as reading and storytelling with a caregiver is encouraged
Children 5-11 and Youth 12-17
Accumulate at least 60 minutes of moderate- to vigorous-intensity physical activity daily; should include:
- Vigorous-intensity activities 3 days per week
- Strengthen muscle and bone at least 3 days per week
- More daily physical activity provides greater health benefits
Exercise and Aging: Cognitive Function
Hi-fit vs. Low-fit during executive function task
Colcombe et al. — Flanker task (ID correct vs. incorrect on screen)
These 3 areas of the brain support task-based improvements that arise from exercise, which are the same regions that support direction-based tasks and antisaccades
Cognitive Impairment and Exercise
- Exercise significantly improves executive functioning, specifically brain processing speed, among community-dwelling older adults who consider their memory declining, 3x/week for 6 months
- Same results following single bout 10 min bike ride
Exercise Intensity
LT = lactate threshold (feel the burn!)
- The burn that a young adult feels at a heavy intensity is the same burn that an older adult will feel at the same individual intensity
– Intensity-matched characteristics for young and old adults alike - So… what intensity provides the best post-exercise improvements to executive functioning?
– Regardless of intensity, significant improvements are documented
Exercise and Aging: affects Cardiorespiratory Systems
Body Height in Adulthood
Declines as we age
Exercise affects osteoporosis
Physical Activity in the Early Years (0-4)
Parents and caregivers should encourage infants, toddlers and preschoolers to participate in a variety of physical activities that:
- Support their healthy growth and development.
- Are age-appropriate, enjoyable and safe.
- Occur in the context of family, child care, school community.
Major Milestones first 18 months of Life
- First 9 months = sit without support
- Then stand with assistance, crawling, standing alone, walking alone
Movement Guidelines
- _Used to only include exercise, but NOW includes both sedentary + sleep guidelines_
Common = limit sedentary behaviour to LESS than 1 hour restrained
Physical Literacy
the ability to move with competence and confidence in a wide variety of physical activities in multiple environments that benefit the healthy development of the whole person
Exercise positively affects age-related deterioration in various physical and cognitive tasks. All of the following statements are true, except:
A single bout of exercise (10 minutes) is not associated with positive effects on cognitive tasks amongst community-dwelling older adults.
- it IS positively associated
Physical activity is not associated with (during pregnancy)…
miscarriage, stillbirth, neonatal death, preterm birth, preterm/prelabour rupture of membranes, neonatal hypoglycemia, low birth weight, birth defects, induction of labour, birth complications
In general, more physical activity is associated with…
greater benefits
Prenatal PA should be considered
front-line therapy for reducing the risk of pregnancy complications, and enhancing maternal physical and mental health
Which pregnant women can participate in PA throughout pregnancy?
All with exception of those with contraindications
Absolute contraindications
may continue their usual activities of daily living but should not participate in more strenuous activities
Relative contraindications
should discuss the advantages and disadvantages of moderate-to-vigorous intensity PA with care provider prior to participation
Resistance training (RT) in children
low- to moderate- intensity resistance exercise should be done 2-3 times/week on non-consecutive days, with 1-2 sets initially, progression to 4 sets of 8-15 repetitions for 8-12 exercises
involves gradual progression under qualified instruction and supervision with appropriately sized equipment can involve more advanced or intense RT exercises
Children
not yet developed secondary sex characteristics — pre-adolescence
Adolescence
time between childhood and adulthood and includes girls aged 12-18 and boys aged 14-19 years
Resistance training
specialized method of conditioning that involves the progressive use of a wide range of resistive loads, including body mass, and a variety of training modalities designed to enhance health, fitness, and sports performance
universal acceptance
RT for children will improve muscular strength and muscular endurance if performed under the supervision of a qualified instructor, using proper technique, gradual training progressions, and proper warm-up and cool-down periods
strength gains comparable to adults BUT…
do not typically provide substantial gains in muscle size
RT is SAFE in children
can decrease incidence and severity of sport injuries
- increase bone mineral density while not adversely affecting maturational growth, cardiorespiratory effect, no effect or improves body composition
RT has positive effect on…
blood lipid profile, psychosocial skills and measures of well being
motor control skills/performance and co-ordination
some degree of improvement in athletic performance in young athletes
recommendations for RT
low- to moderate-intensity 2-3 times/week on non-consecutive days, with 1-4 sets of 6-20 repetitions for 6-12 exercises and generally through a full range of motion
Past perspectives of RT
ineffective in terms of strength improvements, lead to injuries, long-term health consequences, damage of growth plates and premature closure of epiphyses
- strength testing no injuries had occurred and no complaints were reported
health benefits of RT
increase bone mineral density, develop greater muscle strength and endurance, and maintain lean body mass
rehabilitation vehicle for various other conditions
improvements in motor skills and performance while helping resist injury and building up a positive attitude by increasing confidence levels and self-esteem
muscular strength and endurance significantly improve
health benefits of RT
increase bone mineral density, develop greater muscle strength and endurance, and maintain lean body mass
rehabilitation vehicle for various other conditions
improvements in motor skills and performance while helping resist injury and building up a positive attitude by increasing confidence levels and self-esteem
muscular strength and endurance significantly improve
gains in isometric and isokinetic strength, muscular endurance, and flexibility
MOST BENEFICIAL for enhancing muscular strength and endurance
moderate loads and higher repetitions during the initial adaptation period
More effective for/when…
more evident in older boys and greater in lower-body strength
2 days/week compared to 1 day/week
12 week school-based RT program significant improvements of strength, endurance, and flexibility in pre-pubertal boys and girls
gains in muscle strength and power begin to regress towards untrained values of RT is discontinued
bone health
higher bone mineral density
lumbar spine bone mass, volume, and volumetric BMD
thicker cortical bone at the tibia and radius
RT beginning at a young age is also associated with a decreased risk of osteoporotic fractures later in life
– 50% peak bone mass acquired during this period
reduce risk for osteoporosis
peak bone mass
amount of bony tissue present at the end of skeletal maturation
cystic fibrosis with pulmonary exacerbation
improved lung function, leg muscle strength, fat-free mass
cerebral palsy
increase muscle strength and improve daily activities and QoL
burned children
increases in muscle strength, total work resistance, and lean body mass
during supervised strength testing no injuries had occurred and no complaints were reported
most important proper technique and appropriate volume
RT helps children suffering from variousdiseases or health conditions
2 Physiological mechanisms
1) morphological
2) neurological
Morphological adaptations
increase in muscle size, primarily due to an increase in fibre size, potential hyperplasia, and changes in fibre-type composition and connective tissue
- do not seem to influence growth in height and weights of pre- and early adolescent youth
- very limited evidence of hypertrophy in adolescents ; may occur tho—is possible
adults, the increases in muscle cross-sectional area were much smaller than the increases in muscle strength
- if muscle hypertrophy does occur in children, it is likely due primarily to fibre hypertrophy
- myofibrillar growth, proliferation, satellite cell activation
- hyperplasia not been examined in children
Neurological adaptations
- modifications in coordination and learning that facilitate better recruitment and activation of muscles involved in specific strength tasks
- inferred from strength gains that are not accompanied by muscle hypertrophy
- increase in agonist’s activation is likely to result in enhanced force production
- high-repetition and low-repetition — high-load RT programs resulted in a similar enhancement of maximal strength
- in children, largely explained by neurological adaptations such as increased motor unit activation or other changes such as improved inter-muscle coordination or neuromuscular learning
- puberty — learned adaptation becomes permanent in the hypertrophic muscle
Training considerations
- child is ready for sports participation, may be ready for RT; preparticipation medical exam is not required
- over-prescription, excessive pressure may result in overtraining, injury, or burnout
- consideration the maturational status of the youth, training mode, and extent and intensity of other activities
- opportunity to learn about their bodies, experience the benefits of resistance exercise, embrace self-improvement, and feel good about their performances
– can include basic education — proper nutrition, adequate sleep, fitness conditioning, and performance-enhancing drug abuse
Training guidelines
youth RT programs need to be individually prescribed and sensibly progressed over time
- quality of instruction, type of warm-up, choice of exercise, training intensity and volume, and method of testing
1) qualifies professionals provide instruction and attentive supervision
2) consider participant’s cognitive development, cognitive maturity, training experience
3) ensure exercise environment is safe and free of hazards
4) begin each session with a 5-10 min dynamic warm-up period
5) start resistance training 2 or 3 nonconsecutive days/week
6) begin with 8-12 exercises that strengthen the upper body, lower body, and midsection
7) initially perform 1 or 2 sets of 8-15 repetitions with a light to moderate load to learn proper form and technique
8) focus on learning the correct exercise technique and safe training procedures instead of the amount of resistance or weight lifted
9) include specific exercises that require balance and coordination
10) gradually progress to more advanced movements that enhance power production
11) cool down with less-intense activities and static stretching
12) systematically vary the training program over time to optimize gains and reduce burden
Quality of Instruction
- enhances participant safety but direct supervision result in greater program adherence and increased strength gains
- matching the RT program to the needs and abilities of each participant
- always better to underestimate the physical abilities of a child rather than overestimate them and risk negative consequences such as an injury
Type of warm-up
all participants should warm up prior to RT
dynamic warm-up that require balance, coordination, power, and speed have been shown to enhance performance in children and adolescents
- become immediately engaged in class activities and ready to listen to instruction
- pre-event static stretching has been shown to reduce lower-extremity power and isokinetic peak torque in youth
- static stretching exercises during the cool-down session
Choice of exercise
- weight machines, free weights, elastic bands, medicine balls, and body mass exercises have been shown to be safe and effective
- child-size machines most appropriate
- single joint and multi-joint should be incorporated
- start with simple and gradually progress to more complex
olympic style lifts
risk of injury low
- need to learn how to perform early in workout and relatively light load
plyometric training (stretch-shortening cycle exercise)
safe and effective for enhancing muscle power with appropriate training and guidelines
- regularly perform when skip, hop, run, bound, and jump
- neuromuscular system is conditioned to react more quickly to the stretch-shortening cycle
- should begin with less-intensive drills and gradually progress
- relatively few repetitions needed to bring about significant training-induced gains in performance
- done on yielding surfaces with proper athletic positioning and landing
- incorporate this type of training into a well-rounded program, includes other types of strength and conditioning
Balance
- optimal performance and the prevention of athletic injuries
- particularly beneficial for reducing the risk of injury; especially lower back
- progress from simple static activities on stable surfaces to more complex static instability training using devices such as wobble boards, BOSU balls, stability balls
Training Intensity
- amount of weight lifted during the performance of an exercise
Training Volume
- estimated from the number of exercises performed per session, the repetitions performed per set, and the number of sets performed per exercise
Training Intensity and Volume
- sets and repetitions from single-set protocols with a moderate load to progressive training 3-5 sets 70-85% safe and effective
- begin with 1-2 sets 8-15 repetitions light to moderate load on 8-12 exercises
- 2 nonconsecutive days/week is recommended
- gradually progress to 3 sets heavier load
- progression — enhancing movement speed during the performance of selected exercises
– note that not all exercises need to be performed for the same number of sets and repetitions and that in some cases less-intense training can provide needed variation during long-term athletic-training programs - vary the RT program over time to keep the training stimulus challenging and effective
- program variation adequate recovery between training sessions will allow children and adolescents to make even greater gains because their body will be able to adapt to even greater demands
Method of testing
- professionals assess initial strength levels, identify muscle imbalances, develop individualized programs, and monitor progress
- incentive for young participants to resistance train regularly
- no injuries have been reported
- unsupervised and poorly performed strength tests should not be carried out under any circumstances
Risks and Concerns
- an epiphyseal plate fracture has not been reported in any prospective youth RT study
– taught properly, risk of injury to growth cartilage is minimal - regular participation in weight-bearing physical activities is essential for normal bone growth and development
- risk of an overuse soft-tissue injury; lower bak — lower back pain is number one musculoskeletal problem in north American adults
- progressive strengthening exercises for the hips, abdomen, and lower back in youth RT programs as part of a preventative health measure
- minimized with appropriate overload, gradual progression, careful selection of exercises, and adequate recovery between training sessions
Conclusions RT children
properly supervised and instructed RT program using appropriately sized equipment, involving exercises within the child’s or adolescent’s capability, and employing gradual progression can be implemented for youth
- progressive overload stresses are placed on the system
