Aerobic vs Weight Training: Which is Better For Fat Loss (The Duke Study
– Was it Wrong?)
A recent study from Duke
University comparing aerobic versus weight training to see which is better for
fat loss was one of the most publicized studies of the year. My in-box was
bursting with emails from Burn the Fat readers sending me links from news
websites, and asking me, “What do you think of this Tom? Should I stop lifting
weights and focus on aerobics until I get the fat off?” I think the researchers
missed the mark when they concluded that “Aerobic exercise is better” … Read on
to find out why and see what the top trainers, best bodybuilders and hottest
fitness models in the world really say is the best way to burn fat the fastest…
-Duke’s press release headline said:
“Aerobic
exercise trumps resistance training for weight and fat loss.”
The New York Daily News picked
up the story and published this headline:
“Aerobic
training may burn more fat than a combination of weights and aerobics.”
Medical News Today published
this one:
“Aerobic
exercise best way to burn fat, not weights.”
These were the messages getting
passed all around the Internet, usually by people who clicked a “retweet” or
“share” button and didn’t even read the entire research paper. But what did the
study really tell us?
-What’s better for fat loss: aerobics, weight training
or both?
After reading the news blurbs,
you might be led to believe that if your goal is fat loss, you should focus on
aerobics like running or cycling, not resistance training. Although aerobics
(aka cardio) is a proven way to help burn fat, I believe that saying, “Aerobics
alone is best” is sending the wrong message and taking us backwards into the
dark ages of fitness.
After decades of being ignored
or even shunned by the health and medical communities, and after an era of
aerobics dominating the fitness scene, weight training finally got its due
respect as a key element in a total fitness program, including for fat loss. In
the strength and conditioning community, we were thrilled when institutions
like the American College of Sports Medicine (ACSM) finally added resistance
training to their position statements.
We want to see that positive
message continue to be spread widely to the public. Unfortunately, we still
have researchers and the media running you around in circles: First
recommending aerobic training only, then it was aerobics training plus
resistance training, and now they’re saying it’s just aerobics again.
Confused? Trust me, they had it
right at aerobics plus resistance training, especially when you look at the big
picture and not just the body fat percentage alone. Strength training is the
unsung hero in achieving total health and fitness.
Of course, the media loves
stories like these because there is nothing better for getting attention than
controversy and contradiction. While it’s important to keep an eye on new
research and balance those academic findings with real world results, in this
case, I don’t agree with all the conclusions of the study authors.
-Study design
The study, known as
STRIDE-AT/RT (Studies of a Targeted Risk Reduction Intervention Through Defined
Exercise – Aerobic and Resistance Training) was conducted at Duke University in
North Carolina. In this randomized controlled trial, 211 test subjects were
assigned to one of three groups:
1. Resistance training
2. Aerobic training, or
3. Aerobic plus resistance
training
Aerobic training included
treadmill, elliptical trainers or bicycle equivalent to 12 miles per week at
65% – 80% of peak VO2. Resistance training included 3 days per week of weight
training exercises for 3 sets of 8-12 reps. There was a ramp-up period with 1-2
sets during the first month. Exercises were not specified, but they covered all
major muscle groups and workouts were supervised or confirmed.
-These were the general findings:
- All three groups lost fat mass and body fat percentage
- The aerobic training group lost more total body mass (body weight)
than the other two groups
- The resistance training group increased lean body mass more than
the other two groups (confirmed by body composition and thigh
circumference measurements)
- The resistance training group did not reduce body mass. Weight went
up slightly. (However, body fat went down slightly. The lack of decrease
in scale weight was due to an increase in lean mass).
- The resistance training plus aerobic training group decreased body
fat percentage and fat mass more than the other two groups.
Looking at these results, it actually appears as though the resistance
training plus aerobic training group had the best fat loss results: Similar
total body weight loss as the aerobic only group, but greater loss in body fat
percentage and greater loss in body fat mass.
The researchers seem to discount this fact by qualifying their “aerobics
is best” conclusion based on time efficiency or what they believed was the most
important outcome for health benefits.
However, the truth is – and even Duke’s own press release didn’t mention
this – when you read the full research paper and analyze the actual change
scores, NONE of the results of ANY group were very impressive…
-These were the specific findings, by the numbers:
- The
aerobics only group (deemed “most successful”), lost a mere 3.8 pounds of
body weight and 3.6 pounds of fat in 8 months.
- The
resistance training group gained 2.3 pounds of lean body mass and lost
only .57 pounds of fat mass.
- The
aerobic plus resistance group lost 5.36 pounds of fat mass and gained 1.78
pounds of lean body mass. That looks like the winner to me for overall
body composition improvement, but even that is nothing to get excited
about.
Suppose the press release had
said, “Study shows that aerobic training produces almost 4 pounds of fat loss
in 8 months,” or “Aerobic training burns three-tenths of a pound more than
aerobics plus resistance training.” Do you think there would have been so many
headlines? Well, those are the numbers! Why was there any buzz or hoopla about
these study results at all?
With proper program design,
shouldn’t you be able to lose a lot more than 4 pounds in 8 months? In fact,
since this study was conducted on overweight and obese subjects, wouldn’t you
have expected more weight loss than average? (Isn’t it common to see an obese
person lose 4 pounds of bodyweight in
the first week?) Regardless of your starting point, if your goal is
fat loss, would you be happy with less than 4 pounds for 8 months of effort?
-Why the poor results? There are
many possible explanations.
For one, we don’t have that
many specifics about the program design, progression or energy expended from
the weight training workouts. The exercises may have been all low-energy
expenditure machine movements like leg extensions. There may have been poor
application of progression and periodiziation. And in the aerobic group, the
volume and/or intensity of training may may not have been enough.
will continue…
till next time!
