Why doesn't my exercise routine work?

[Guest guest]

Consider this.

Full article with links (http://www.athleteinme.com/ArticleView.aspx?id=254)

Trimmed article below.

Exercise and Obesity

Author: Stan Reents, PharmD

Posted: 5/6/2007 10:06:44 AM

Health statistics show that one-third of Americans are overweight (BMI > 25) and

another third are obese (BMI > 30). Obesity is a risk factor for a lengthy list

of other diseases, including hypertension, diabetes, metabolic syndrome, heart

disease, joint problems, and more. These diseases, in turn, promote the

development of still more medical problems: hypertension increases the risk of

kidney disease and stroke; diabetes leads to problems with vision and peripheral

circulation, and on and on.

Recently, the media and the medical profession have finally started focusing on

obesity as not only a personal health issue, but as an impending medical crisis

(Manson JE, et al. 2004; Vastag B. 2004). While scientific evidence shows that

obesity does have a genetic component, lifestyle factors are probably more

important. So, if that is true, then obesity should be reversible.

EXERCISE RECOMMENDATIONS FOR WEIGHT LOSS FROM ACSM

The standard recommendation for people who are overweight (BMI > 25) or obese

(BMI > 30) is, of course, " diet and exercise " . But, what exactly does that mean?

In 1995, the American College of Sports Medicine (ACSM) recommended at least 150

minutes of exercise per week (Pate RR, et al. 1995). That translates to 30

minutes per day on 5 days each week. But subsequent research suggests that 150

minutes per week is not enough, and that 200 minutes per week (or more) will not

only achieve a greater weight loss, but, more importantly, will do a better job

of keeping that weight off (Jakicic J, et al. 1999).

EXERCISE FOR OBESITY: DOES IT WORK?

However, many in the scientific and medical community believe that exercise

isn't very effective for weight-loss. Certainly, many obese people will tell you

that it doesn't work for them.

For example, in 1 study of postmenopausal women, 12 months of exercise 5 days

per week led to only a 1.3 kg weight loss (Irwin ML, et al. 2003). That's not

very encouraging.

" But wait, " you might be saying, " exercise burns calories, and this is how you

lose weight, right? "

So, does exercise work, or not? The short answer to this question is: " it

depends " .

Of course exercise burns calories and it's also true that if more calories are

burned than consumed, then body weight will decrease. Even when taken to the

extreme, these relationships apply. Consider, for example, Tour de France

cyclists: despite an intake of 6000-7000 calories per day, they still lose

weight during the race.

But, in obese subjects who are attempting to lose weight with exercise, the

story isn't quite that straight-forward. Here's why:

REASONS WHY EXERCISE IS ONLY MODERATELY EFFECTIVE FOR WEIGHT LOSS IN OBESITY

The most important explanation why exercise isn't effective for many people

trying to lose weight is that exercise represents only a small percentage of the

calories burned in any 24-hr period. Even a full hour of vigorous exercise in

these people constitutes only about 10-30% of the total calories they burn up in

a given 24-hr period. Contrast that to the Tour de France athlete who cycles at

a furious pace for 6 solid hours, burning up as much as 9000 calories in a

single day.

In the average person, " routine daily activities " (vacuuming, raking, sweeping,

running errands, etc.) are responsible for the largest share of the calories

expended each day:

Calories burned during daily activity: 65-75% of the day's total

Calories burned during exercise: none if sedentary; up to 30-35% if exercise is

vigorous and prolonged

Calories burned during digestion: 5-10%

Unfortunately, obese people simply aren't as active as thinner people:

In 2005, researchers at the Mayo Clinic found that thinner people were more

active than overweight people. The subjects wore a specially-designed body suit

that tracked physical movement throughout the day, including movements as small

as toe-tapping. Scientists call this " NEAT " : non-exercise activity thermogenesis

(Levine JA, et al. 1999). Assessments were made twice per second

around-the-clock for 10 days.

The study showed that heavy persons sit about 150 minutes more each day than

lean people do. This translates to 350 fewer calories burned each day by the

obese person. (Levine JA, et al. 2005).

And claims of a " slow metabolism " are not relevant for the majority of people

who are overweight or obese:

In 1992, a report appeared in the New England Journal of Medicine evaluating the

metabolic rate of obese subjects (BMI > 27) who claimed to have a " slow

metabolism " as their reason for being unable to lose weight. Subjects were

monitored for 14 days. The study revealed that these self-proclaimed " slow

metabolizers " actually underreported their true food intake by 47% and

overreported their physical activity by 51% (Lichtman SW, et al. 1992).

Weight loss occurs if more calories are burned than consumed. But, even if a

person exercises for an hour, they may not lose weight if they consume an

excessive number of calories that day.

EXERCISE DOES WORK

Exercise does work. Here are some positive results:

• Distance Running: Obese runners lost an average of nearly 40 kg and dropped

their body fat down to 14% as a result of running 95-km (about 60 miles) per

week with no dietary changes (Tremblay A, et al. 1984).

These are very impressive results, but very few people are willing to run 95-km

per week. Fortunately, it turns out that exercise doesn't have to be punishing

to produce effective weight loss:

• Walking: Researchers at Duke University compared running with brisk walking.

Overweight adults (average BMI of 29.7 kg/m2) who walked 30 minutes per day at

40-55% of maximum oxygen uptake avoided gaining additional weight. Patients were

instructed not to diet during the 8-month study. Subjects in all 3 groups who

exercised lost body weight and fat mass, with the group who ran 20 miles/week

losing the most. However, when running 12 miles/week was compared with walking

12 miles/week, both groups lost weight and fat mass. Subjects who did not

exercise gained about 2.5 lbs. Thus, it appears that brisk walking is as

effective as running (Slenz CA, et al. 2004).

• Aerobic Exercise: A study of post-menopausal women with a BMI > 25 who engaged

in aerobic exercise (mostly walking and biking), showed that the amount of body

fat lost was proportional to the amount of weekly exercise (Irwin ML, et al.

2003):

>195 minutes/week: 4.2% loss in body fat

136-195 minutes/week: 2.4% loss in body fat

<136 minutes/week: 0.6% loss in body fat

WHY OBESE AND OVERWEIGHT PEOPLE SHOULD EXERCISE REGULARLY

Even if weight loss is minimal, overweight and obese people should still

exercise regularly (after first getting clearance from their physician). Many

more health benefits are obtained with regular exercise compared to dieting:

• Aerobic exercise is beneficial for the cardiovascular system. In addition to

strengthening the heart muscle, exercise will stimulate the circulation,

increase oxygen uptake by skeletal muscle, lower blood pressure at rest, and

reverse the process of atherosclerosis. Aerobic exercise can effectively lower

blood pressure in obese subjects with hypertension even if no weight is lost.

• Resistance exercise strengthens the bones and maintains muscular strength. It

doesn't take much resistance to have a positive effect on bone density: In a

study of squash players, simply swinging a light-weight squash racquet produced

a noticeable increase in the density of the bones of the dominant arm. Muscle

strength is improved by any form of resistance-training (eg., weight-lifting,

push-ups, sit-ups, squats, working-out with rubber bands, etc.), but even

walking will increase muscle strength in the muscles of the legs and back.

In fact, if there ever was a " magic bullet " in medicine, it would be exercise.

, MD, then Editor-in-Chief of the American Journal of Cardiology

once referred to exercise as " an agent with lipid-lowering, antihypertensive,

positive inotropic, negative chronotropic, vasodilating, diuretic, anorexigenic,

weight-reducing, cathartic, hypoglycemic, tranquilizing, hypnotic and

antidepressive qualities " ( WC. 1984). That was back in 1984. Today, we

know that, in addition to all those properties, exercise is also beneficial for

osteoporosis, sexual dysfunction, and many other medical problems.

EXERCISE RECOMMENDATIONS FOR OLDER OBESE SUBJECTS

People over age 65 rarely follow diet and exercise programs for weight loss.

Obesity is increasing among the senior population just as it is for other age

groups. This results in significant health and lifestyle concerns.

Weight should be a greater concern for older populations because of the higher

occurrence of secondary conditions such arthritis, heart disease, and

hypertension. In addition, as a person grows older and experiences a decline in

strength, balance, and cardiovascular endurance, any excess weight makes

performing activities of daily living more difficult. For these reasons, weight

reduction always should be a goal for any older individual who has been

classified as overweight or obese.

The American Council on Exercise (ACE) recommends the following for older

overweight subjects:

1) Aim to exercise three days per week initially. Gradually work up to five days

per week, varying the program on alternating days to prevent boredom.

2) The higher the level of obesity, the more difficult it will be to exercise.

Start with 30 minutes of exercise broken down into 10 minutes of cardiovascular

activity (eg., walking on a treadmill, stationary cycling), 10 minutes of

weight-lifting using 5-10-pound dumbbells, and 10 minutes of flexibility

exercises. Increase the duration of each phase of exercise as you become more

capable and comfortable with the program. Rest as necessary to prevent premature

fatigue.

3) Intense effort is not the goal for elderly people. If you cannot carry on a

conversation while walking on the treadmill or riding the exercise bike, you are

exercising too hard.

4) If your leg muscles are weak, try non-weight-bearing activities, such as

aquatic exercise, and arm and leg cycling.

5) Do not be too concerned about your weight during the early stages of the

program. The primary goal is regular exercise.

Hiring a personal trainer, at least during the first few exercise sessions, is

highly recommended.

TIPS FOR ADDING MORE ACTIVITY INTO YOUR DAILY ROUTINE

Exercise can be an effective component of a weight-loss program, however, most

people simply don't exercise enough to make it work for them. Like saving loose

change, small amounts of activity throughout the day add up. Here are some

suggestions for integrating moderate exercise into your lifestyle:

• Park at the far end of the parking lot

• Take the stairs

• Carry your bags of groceries to your car instead of using the cart

• Mow your lawn with a push-mower

• Walk or bike to the store whenever possible

• Convert the daily task of walking the dog into your daily run and take the dog

with you

• Buy some simple exercise aids (jump rope, exercise bands, exercise watch,

running shoes, etc.) and carry them with you when you travel

•Surround yourself with other people who exercise regularly; develop social

circles based on exercise (walking in the mornings, bike trips on weekends,

tennis leagues, etc.)

• Stick with your lifestyle change long enough until it becomes a habit

SUMMARY

Exercise should be a part of every weight-loss plan. Exercise not only helps you

burn calories and lose weight, but it also provides a wide variety of other

health benefits, such as lower blood pressure, increased bone density, and a

stronger heart, just to name a couple. Also, exercise, if done regularly, helps

to keep the weight off after it is lost.

• Exercise at least 5 days per week for a total of at least 150 minutes per

week. If possible, exercise 200 minutes per week. Even if no weight is lost, you

will be obtaining health benefits (lower blood pressure, for example). Also,

it's possible that you are losing fat but this trend is disguised because you

are simultaneously adding muscle.

• Exercise does not have to be intense to burn calories. Walking has been shown

to be effective. Slow bicycling, however, because most of your body weight is

supported, is probably not very effective.

• Remember, it only takes a calorie-deficit of 500 calories per day to produce a

1-pound-per-week weight loss. But, don't try to lose more than 2 pounds per

week. Rapid weight loss is unhealthy. So, if you do the math, it will take you a

year to lose 100 lbs.

ABOUT THE AUTHOR

Stan Reents, PharmD, is a former healthcare professional. He holds Personal

Trainer and Lifestyle Counselor certifications from the American Council on

Exercise and has been certified as a tennis coach by USTA. He is the author of

Sport and Exercise Pharmacology (published by Human Kinetics).  He can be

reached at: Editor@....