Exercise and Weight Control

Dr. David L. Gee

FCSN 446/PE 446

Nutrition, Weight Control, and Exercise

Benefits of Exercise for Overweight Individuals

Weight Loss Related Benefits Health Benefits Independent of

Weight Loss Psychological Benefits

Why do Americans not exercise?

Successful Approaches to Adopting and Maintaining a Physically Active Lifestyle

NIH Consensus Development Conference Statement, Dec. 1995

Perceives a net benefit– Chooses an enjoyable activity

– Feels competent doing activity

– Feels safe doing activity

Successful Approaches to Adopting and Maintaining a Physically Active Lifestyle

Easy access to activity Activity fits into daily schedule Financial and social costs acceptable Minimum negative consequences

– loss of time– negative peer pressure– problems with self esteem

Successful Approaches to Adopting and Maintaining a Physically Active Lifestyle

Able to successfully address issues of competing time demands

Balance labor saving devices and sedentary activities with activities that involve higher levels of physical exertion

Exercise for the Weight Loss: Intensity vs. Duration

Recommendations for overweight subjects who are sedentary

Begin with lower intensity exercises Work on increasing duration first Focus on regular program (5-7 days/week) Gradually increase intensity once available

time is limiting Add weight training if time permits Just do it!

OK, exercise is important.

But, how important is “everyday/lifestyle” activity?

Lifestyle vs Structured Activity

JAMA (Jan. 1999) Sedentary men (116) & women (119) 6 months intensive intervention

– lifestyle physical activity program

– structured exercise program 18 months maintenance intervention

Lifestyle vs Structured Activity

LifestyleProgram

StructuredActivity

changeactivity(Cal/kg/d)

+0.84 +0.69

changeVO2max(ml/kg/min)

+0.77 +1.34

Lifestyle vs Structured Activity

LifestyleProgram

StructuredExercise

changesystolic BP(mmHg)

-3.63 -3.26

changediastolic BP(mmHG)

-5.38 -5.14

Lifestyle vs Structured Activity

LifestyleProgram

StructuredExercise

changeBody Weight(kg)

-0.05 ns -0.69 ns

change% body fat

-2.39 % -1.85 %

Conclusions: Lifestyle Programs have similar beneficial changes as Structured Exercise Programs

Training Effects of Short and Long Bouts of Brisk Walking in Sedentary Women.

MSSE 30:152-157 (1998)

47 women, @70-80% HRmax, 5X/wk, 10 weeks– Long walks: 30 min walking– Short walks: 3x10 min walking

Aerobic capacity increased equally in both walking groups

Decreases in BW was greater in short walk (1.7kg) than long walkers (0.9kg)

Waist circumference decreased greater in short walk (3cm) than long walkers (1.8cm)

Conclusion: accumulations of shorter walks at least as beneficial as single long walk.

Effects of intermittent exercise and use of home exercise equipment on adherence, weight loss, and fitness.

JAMA 282:1554-1560

148 obese women, 18 month weight loss program– home treadmill + 4-5 25-35min/wk walks– home treadmill + 10-14 15-20 min/wk walks– no equipment + 10-14 15-20 min/wk walks

Weight loss equal in first 6 months– (6-7kg)

Weight regain similar in last 12 months– 1.5-4kg, slightly higher in group w/o treadmill

Effects of intermittent exercise and use of home exercise equipment on adherence, weight loss, and fitness.

JAMA 282:1554-1560

Dose-response relationship between weight loss/maintenance and weekly exercise time.

150 min/wk:– 7kg loss @ 6 mo, 3.5 kg regain at 18 mo.

150-200 min/wk– 10.5 kg loss @ 6 mo, 2 kg regain at 18 mo.

>200 min/wk– 12.5 kg loss @ 6 mo, no regain at 18 mo.– 200min/wk = 2-3 walks/day for 10-15min each

Active/highly active– > 10,000 steps/day

– 20% men

– 13% women

Sedentary lifestyle– < 5,000 steps/day

– 32% men

– 33% women

Factors affecting steps/day Age

– Younger>older

Income– Low<high

– Ethnicity NS

Marital status– Single/divorce>married

BMI– Obese<overweight<normal

Conclusion:

“Increasing steps per day appears to be a good target to use in interventions to increase physical activity.”

“Even in Colorado, one of the leanest states, very low levels of physical activity are seen in much of the population.”

Exercise Recommendations

Old ACSM Recommendations (1990)– 3-5 days/week

– 60-90% of max. HR

– 20-60 min/session

ACSM 2002– 30 minutes of moderate exercise most days of the week

IOM – DRI Energy - 2002– 60 minutes of moderate exercise 7 days a week

Dr. Gee’s Recommendations for Exercise and Weight Loss

Priority 1– Emphasize active lifestyle every day– brainstorm ideas– Pedometers & 10,000 step programs

Priority 2– Include structured exercise most every day– focus first on endurance, second on intensity

Priority 3– Incorporate weight training 2-3x/week

Considerations for the Overweight Exerciser

Many of those overweight:– are currently inactive

– were never active

– feel awkward exercising

– have poor self image

Considerations for the Overweight Exerciser

Very gradual introduction and progress Appropriate types of exercise group support instructor support low impact heat intolerant measure HR frequently

Considerations for the Overweight Exerciser

Make it a high priority (incentives)

Use as a substitute for problem behavior, not as a punishment

measure girth in addition to weight