Exercise for the Special Population Exercise Science 2001 Objectives: Using examples, To identify special populations To identify physical activity / exercise needs of special populations To integrate principles of exercise training in the implementation & the evaluation of exercise training programs Special Populations Target population – Group vs. Individual, age group, gender Identify Needs – Goal Setting Design Program – Record Keeping Evaluation – Pre and post testing So…. Who are they? Special Population Special Population = Adapted State Population at risk – – – – population with sedentary lifestyle low cardiorespiratory fitness women: aged, osteoporosis children with obesity Population with chronic disabilities – e.g. ankylosing spondylitis, diabetes mellitus, chronic obstructive pulmonary disease, cystic fibrosis, rheumatoid arthritis, poliomyelitis, stroke, amputations, spinal cord injury… Lifelong Fitness Lifestyle Four phases of natural history of exercise Sedentary Adoption Maintenance Time Drop-out Resumption Guidelines To implement an effective exercise programme: An understanding of the body responses to exercise in diseases/conditions Unique adaptations to exercise training in different age group with regard to strength, functional capacity, motor skills Guidelines (Cont’d) Identify risk factors / precautions / contraindications prior to participation in physical activity Identify determinants of physical activity Integrate the principles of exercise training Define ways to monitor and evaluate the effectiveness of the program Local Data 1 Report on Healthy Living Survey 1999 Department of Health Cross-sectional telephone survey n = 3,270 Aged 18-64 years Results of the Healthy Living Survey 51% of men and 47% of women engaged in exercise (at least 30 minutes) within last one month Participation in exercise drop markedly for both sexes from 70% (in age group 18-24) to less than 40% in age group (age 45-54) Results of the Healthy Living Survey 52% had done something to improve health or to prevent diseases in the past year Exercise was the most common action Major barrier: lack of time On average spent 2.7 hours daily watching TV Local Data 2 (1999) Chinese University of Hong Kong Interview survey n = 26,111 Aged 10 to 20 from 48 primary and secondary schools Results of the CUHK Survey Have you engaged in any leisure time exercise that make you sweat last week? NO percentage: – P4 to P6: 13.8% – F4 to F7: 25.8% Have you watched TV for 3 hours or more last week? YES percentage: – P4 to P6: 54.3% – F4 to F7: 51.2% So…. What does it mean? INACTIVITY - a major health problem Association between sedentary lifestyle and morbidity / mortality from chronic disease - Evidence?? Evidence (Blair and Brodney, 1999) Association of physical activity or cardiorespiratory fitness to the outcomes of mortality: Cardiovascular disease Coronary heart disease Hypertension Type 2 diabetes mellitus Cancer + ++ + ++ Effects of Physical Activity on Health Outcomes in Adolescents Aerobic Fitness Body Fat Blood pressure HDL cholesterol LDL cholesterol 0 Musculoskeletal injuries BMD Exercise Prescription Considerations An Example Adolescence Defined as ages 11 - 21 Pre-pubescent preadolescent Post-pubescent adult Physiologic Characteristics of Exercise in Preadolescents (ACSM Resource Manual, 1998) Immature cardiovascular system Higher O2 consumption per unit of body mass (i.e. higher metabolic rate) Lower SV, compensated by higher HR Higher RR Poor sweating capacity Large surface-to-mass ratio RPE perceived as easier for a given workload Physiologic Characteristics of Exercise in Preadolescents concentration and rate of utilization of glycogen ability to utilize muscle glycogen and produce lactate lower anaerobic capacity than adults Reach metabolic steady state faster, lower oxygen deficit, faster recovery Rely more on aerobic metabolism Implications Can perform endurance task fairly well Greater fatiguability in prolonged highintensity task Ability to perform intense anaerobic task lower than adults Low tolerance to extreme heat / cold Thermoregulation less efficient - less tolerance for exercising in the heat susceptible to heat exhausation In planning exercise program: Preparticipation examination Avoid anaerobic training (concentrate on skill and movement in aerobic sports such as basketball and soccer) Intermittent activities preferred Intensity and duration should be lower initially gradually increase In planning exercise program: Special attention to acclimatization (avoid high heat and humidity) Fluid replacement Be conservative / prescribe an easily tolerable program Have a high index of suspicion for injury Skeletal System Active musculoskeletal development Muscle-tendon units accommodate to the rapid growth of long bones flexibility compromised At puberty, relative over-growth of long bones to soft tissue muscle imbalance Repetitive microtrauma on vulnerable prestressed muscle-tendon units tendinitis, bursitis, apophysitis, stress fractures Implications Gradual progression of exercise Avoid extremes in exercise duration and intensity Adequate period of warm-up, stretching and cool-down exercises Determinants of Physical Activity Demographic Biological Psychological / emotional Social and cultural Physical Environment Facts Boys more physically active than girls Physical activity declines dramatically with age (from age 13 to 16) Self-efficacy strong predictor Perceived barriers: lack of time and lack of interest Enjoyment a strong correlate Facts Social influence strong++ - peer and parents influence Physical environmental strongly associated with physical activity (especially preschool children) Local Data Lindner and Sit, 1998 n = 4,690 (P.5 to F.7) Reasons for participation: – – – – For Fun For health and fitness To be with friends To become good at the activity Local Data Reasons for non-participation: – Prefer to do one’s ‘own thing’ (? Not attracted by the regularity, commitments and expectations being involved in sports) Reasons for withdrawal: – Need time for studying – Wanting to spend more fun time on other leisure activities – Wanting time to be with friends Implications Target high risk group - female adolescents Build perceptions of competence or self-efficacy Fun enjoyable activities Implications (Cont’d) Reduce perceptions of barriers Social support from friends Stimulate parental assistance Increase time to spend outdoors Physical Activity Guidelines International Consensus Conference on Physical Activity Guidelines for Adolescents (Sallis and Patrick, 1994) Health Education Authority (Biddle et al, 1998) International Consensus Conference on Physical Activity Guidelines for Adolescents All adolescents should be physically active daily, or nearly every day Engagement in 3 or more days/week of activities that last for 20 or more minutes that require moderate to vigorous levels of exertion Health Education Authority (UK) Participation in physical activity of moderate intensity for 1 hour/day Young people who currently do little activity should participate in physical activity of moderate intensity for at least 30 minutes/day (note: consistent with adult guidelines) At least 2 days a week, engage in exercise that enhance/maintain muscle strength, flexibility and bone health Exercise for Obese Children Exercise for Obese Children Local Data: Report from Department of Health Health services provided to schools review 13.2% primary school children as obese Related to homework, watching TV, computer games, surfing on the net all sedentary behaviours!! Fitness or Fatness?? Measures of adiposity and sedentary behaviours are consistently related Children with high level of total body fat mass and visceral adipose tissue have increased factors for coronary artery disease and NIDDM Obesity predicts poor adherence to exercise programs Obesity in childhood adulthood Physical activity best predictor of weight loss maintenance Think about: Physical Activity Guidelines for Adolescents Determinants of Physical Activity Principles of exercise training Components of physical fitness Evaluation Tools Follow up period Evaluation Tools Measurements of: Cardiovascular fitness Body fat composition Physical activity level Components of the Program Exercise Nutrition Social Support - parents involvement Behaviour change Relapse prevention Characteristics of the Exercise Programs Home based vs. site-based Build activity into child / adolescent’s lifestyle Negative energy balance Think about the activity guidelines Physical Activity Levels Low intensity - 30-50% VO2 max; HR 120-149 beats/min; 2-4 METS Moderate intensity - 50-70% VO2 max; HR 150--169 beats/min; 5-7.5 METS High intensity - > 70% VO2 max; HR > 169 beats/min; > 7.5 METS HR monitoring considered for assessing moderate to vigorous activity Initiatives in Hong Kong Exercise Program