A study among 1.7 million survey participants confirms these findings. It
found that participation in either strength training or aerobic training is associated
with a lower prevalence of obesity and that the combination of these activities is
associated with an even lower prevalence of obesity. These results are in keeping
with the recommendation that both aerobic and resistance physical activity are synergistic
in benefiting health.
In theory, to lose fat, it does not matter if the necessary calorie deficit is brought
about by dietary calorie restriction or increased energy expenditure through physical
activity. But for the average person, the difference in calorie expenditures be
tween a sedentary and an active person may not be very great. Undoubtedly hours
of exercise helped “The Biggest Losers,” but many studies have shown that exercise
alone is not an efficient “real world” way to lose weight compared to the adoption
of a diet that causes restriction of calories.
A review of more than 500 studies, including randomized, controlled trials (RCTs)
shows only modest weight loss with exercise programs alone and only modest increases
in weight loss when an exercise intervention is added to dietary restriction. In most RCTs, the energy deficit from the prescribed exercise was modest, and the calories expended were far smaller than those resulting from dietary restriction.
However, in studies that featured high levels of exercise, of sufficient
magnitude to produce an energy deficit of 500 to 1,000 calories per day, participants
substantially augmented weight loss.
A 2018 study suggests the importance of physical activity of long duration to weight
loss. The study was conducted to determine the amount of compensation for exercise
energy expenditure either by eating more or moving less at two levels of
exercise—the expenditure of either 1,500 or 3,000 calories a week. Overweight-to-obese
sedentary men and women exercised expending either 300 calories (taking
about 30 minutes) or 600 calories (requiring about 60 minutes) five days a week for
four months. The 3,000 calorie/week group decreased both percentage and weight
of body fat, while the 1,500 calorie/week group did not. Both groups compensated
for the extra expenditure of calories in their workouts by extra eating. The 30
minutes a day group replaced nearly two-thirds of the calories they burned, but the
60 minutes a day group replaced only one-third of the calories they burned, so they
lost more fat. The investigators pointed out that even with high levels of exercise,
limiting calories is still needed for weight loss.
Studies show a clear dose-response relationship between physical activity and
weight maintenance. Similar to the experience of those participating in the NWCR,
two rigorous studies found that about 80 minutes per day of moderate intensity activity
added to a sedentary lifestyle was needed to prevent weight regain in the year
after weight loss.
Time constraints and physical limitations that may be significant
for overweight or obese adults make high levels of physical activity difficult
to achieve and sustain. The loss of adipose tissue that occurs when an individual’s
exercise level increases may not lead to weight loss because of a desirable increase
in lean muscle mass. Exercise can reduce body fat, increase lean body mass, and
improve cardiovascular biomarkers even if it does not change body weight
This blog presents opinions and ideas and is intended to provide helpful general information. I am not engaged in rendering advice or services to the individual reader. The ideas, procedures and suggestions in that are presented are not in any way a substitute for the advice and care of the reader’s own physician or other medical professional based on the reader’s own individual conditions, symptoms or concerns. If the reader needs personal medical, health, dietary, exercise or other assistance or advice the reader should consult a physician and/or other qualified health professionals. The author specifically disclaims all responsibility for any injury, damage or loss that the reader may incur as a direct or indirect consequence of following any directions or suggestions given in this blog or participating in any programs described in this blog or in the book, The Building Blocks of Health––How to Optimize Your Health with a Lifestyle Checklist (available in print or downloaded at Amazon, Apple, Barnes and Noble and elsewhere). Copyright 2021 by J. Joseph Speidel.