fitness prog chapter 9

CVD mortality

• overweight and mildly obese have better prognosis than normal weight

• possible explanations for paradox

  • need to measure body composition rather than weight

  • need to account for cardiorespiratory fitness

health risk of obesity

• all cause mortality

• hypertension

• dyslipidemia

• type 2 diabetes

• stroke & coronary heart disease

• gallbladder disease 

• osteoarthritis 

• sleep apnea

• many types of cancer 

• depression & anxiety 

• decreased quality of life 

• decreased ADL 

health risks of underweight

• malnutrition

• fluid electrolyte imbalances

• osteopenia, osteoporosis, and fracture

• muscle wasting

• cardiac arrhythmias and sudden death

• renal and reproductive disorders

underweight BMI

< 18.5 kg/m2

overweight BMI

25.0 to 29.9 kg/m2

• children 95th percentile for age and sex

Obese BMI

> 30 kg/m2

Children and adolescents

• overweight> the 85th for BMI

• obese > 95th percentile for BMI

• cutoffs for age and sex are still under discussion

• considerable variability in %BF for a given BMI

what is body composition

• lean body mass

• fat free mass

• essential fat 

• non essential fat

lean body mass

• includes essential fat

• weight of fat-free tissues & life sustaining lipid organs

fat free mass

• weight of nonfat tissues of the body

• water

• protein

• bone

essential fat 

• minimal amount of body fat needed for normal physiological functions 

• women 8-21%

• men 3-5%

Non-essential (storage) fat

• body fat in excess of essential fat 

• excess fat stored in adipose tissue 

• some non-essential required

global pandemic prevalence

• overweight: >1.9 billion

• obese:> 650 million

• generally wealthier countries = increase obesity prevalence

Untied states prevalence

• obese: 41.9%

• severely obese (BMI>40 kg/m2) 9.2%

• substantial increases in obesity over the past 25 yrs

Childhood obesity prevalence

• increasing prevalence over past 50 yrs

• varies globally

  • high prevalence overweight in South Pacific Islands of

  • high prevalence of underweight in India

• 2030 projection of childhood obesity in U.S: 25%

healthy people 2030: u.s. goal

• children: decrease obesity to <15.5%

• adults: decrease obesity to <36.0%

• currently US population is moving in the opposite direction of those goals

fat distribution

• genetic variability in fat distribution

  • android: upper body obesity

  • gynoid: lower body obesity

• Visceral and ectopic fat=increase risk of cardiometabolic diseases compared to subcutaneous fat

Types of obesity

• genetic variability in fat distribution

  • android: upper body obesity

  • gynoid: lower body obesity 

• visceral and ectopic fat=increased risk of CHD, diabetes, and dyslipidemia 

• fat distribution assessment: waist to hip ratio 

  • males at risk if WHR> 0.94

  • females at risk if WHR>0.82

cause of obesity

• Multifactorial 

  • personal behaviors: diet and exercise

  • genotype-phenotype interactions

  • environment and socioeconomic status

• interaction between genes and behavior or environment

  • genes: contribute to weight gain and fat distribution

  • obesogenic enviornment

    • mechanized lifestyle

    • easily accessible energy-dense food

Kilocalorie (kcal)

unit of heat energy 

Energy yield of macronutrients

Carbohydrates: 4kcal/g

protein: 4 kcal/g

fat: 9 kcal/g

3500 kcal

1 lb of fat

energy balance

• energy intake=energy expenditure

  • Positive: weight gain

  • negative: weight loss

• weight managment requires a combo of proper diet and daily PA

set body weight goal 

• measure body composition 

• use FFM and desired % BF to set realistic goal (target weight)

Assess kcal intake

food record and dietary software

assess kcal expenditure

factorial or TEE method

TEE total energy expenditure 

• TEE=RMR+dietary thermogenesis+EAT+NEAT

  • TEE- total energy expenditure

  • RMR- resting metabolic rate

  • EAT- exercise activity thermogenesis

  • NEAT- non-exercise activity thermogenesis

RMR

• is the largest contributor to TEE

  • FFM is most influential of RMR

Designing weight loss programs

• recognize that improvement in cardiorespiratory and muscle fitness may be more important than weight loss

• exercise: conserve FFM 

• Use NIH body weight planner 

• collaborate with nutritionist 

• periodically assesses body composition 

Exercise prescription for weight loss

• exercise alone without diet has only modest effect

• collaborate with a nutritionist

• exercise >350 min/wk is recommended

• dose response relationship

• frequency:daily

• intensity: moderate; duration is more important

• time >60 min

• type: aerobic for weight loss, but resistance training to preserve FFM

Benefits of exercise for weight loss 

• exercisers maintain weight loss more than non-exercisers

  • minimize loss of FFM

  • Offset diet included reduction in RMR

• Metabolic adaptations: better “fat burner”

• increase GH and catecholamines

• increase aerobic fitness

  • ability to expend more kcal

Weight gain programs 

• increase intake by 350 to 475 kcal/day

• diet 

  • consult with nutritionist

  • protein intake: 1.4 to 2.0 g/kg/day; protein intake every 4 hrs

• use NIH body weight planner

• exercise: high volume resistance training

• monitor body composition

exercise prescription for weight gain 

• frequency: each muscle group 2 days/ wk 

  • novice: >4 sets/muscle group/wk

  • advanced: 10 sets/muscle group/wk

• intensity: 70% ot 75% of 1-rm or 10-to-12 RM

• Time: 60 min

• Type: high volume resistance training

Exercise prescription for body composition

• increase FFM while decreasing FM

  • very difficult to achieve

• combination of aerobic and resistance exercise

• high protein diet

Physically active lifestyle 

• daily aerobic exercise 

• strength and flexibility exercises 

• increased recreational leisure time physical activities 

• increased physical activity in the daily routine at home and work- restricted used of labor saving devices 

Healthful eating

• consume a variety of nutrient dense foods within a among the basic food groups

• limit intake of saturated and trans fats, cholesterol, added sugars, salt and alcohol

• meet recommended intakes within energy needs by adopting a balanced eating pattern

Carbohydrates

• to maintain and replenish glycogen stores, you need a daily CHO intake of

  • 7 to 8 g*kg -1 of body weight if you engage in low intensity moderate duration physical activity

  • 7 to 12 g*kg of body weight if you engage in high intensity or long duration exercise

Protein 

• essential amino acids are needed for protein synthesis 

• in general daily protein requirement of the body is ~0.8 g*kg-1 

• for endurance athletes recommended intake is 1.2 to 1.4 g*kg-1 

• strength trained athletes may need as much as 1.7 to 2 g*kg-1 

Fats

• some dietary fat is needed to supply fatty acids and to absorb fat soluble vitamins

• Fats must be chosen wisely

  • to promote weight loss and to reduce serum cholestrol level, limit these intake

    • saturateed fat and trans fatty acids (<7% of total calories)

    • total fat (25% to 35% of total calories)

    • cholestrol (<200 mg per day)

Vitamins 

• no need to supplement if diet is balanced 

• those restricting food intake to lose weight or make weight may benefit from supplementation 

• supplementation is beneficial only for those who are deficient in one or more vitamins 

prehydration, hydration, and rehydration

• Guidelines for hydration

  • about 4 hours before exercise, drink 5 to 7 ml/kg of body weight of water or a sports beverage

  • replace fluid depending on sweat rate, exercise duration, and opportunities to drink

  • drink at least 6 ounces of fluid every 15 to 20 minutes

  • consume drinks containing CHO (6-8%) and sodium when endurance exercise is more than 1 hour

  • drink at least 16 ounces of fluid for every pound of body weight lost during exercise

% body fat/TBW goal 

• assess current body weight 

• assess current % fatness

• choose reasonable goal 

example: 25 yr old male, 90kg, 25% fat, goal is 20% fat