Weight Training for Fat Loss – Contradictory Study Evidence

Does cardio or weights work better for fat loss?

A “man on the street” survey (Sorry gals, it’s an outdated saying) nearly always puts cardio as the best way to lose fat. A trainer poll isn’t nearly as definitive, but weight training occupies a much higher place. What do the eggheads say about weight training for fat loss vs cardio?

Okay, so I’m about to launch a post series on weight training for fat loss. I’ll be chatting with some interesting characters along the way. From everything I’ve gathered through years in fitness, weight training is the more time-efficient way to lose fat. You’ll also look better when the fat melts away, as there’ll be some shape on your bones instead of some sticks in the torso.

Some studies quibble with this, sticking to the age old perspective that you’ve gotta hop on the bike, track, or Zumba class to melt the fat away. I looked at one from Duke University done in 2012. It about the most popular of studies claiming cardio trumps weight training for fat loss. There were a few things that made me raise an eyebrow…

Weight Training vs Cardio Fat Loss Study – Problems With The Duke University Effort

The 2012 Duke University fat loss study found that cardio was more effective than weight training for fat loss. Unfortunately, that study has gotten a lot of play in the last couple of years.

Study author Dr. Chris Slenz PhD even went so far as saying “It’s not that resistance training isn’t good for you; it’s just not very good at burning fat.” Hmmmm. I’d say, and there are a crap load of personal trainers that’ll back me on this, that he’s not doing it right. Sorry, Doc!

From my perspective that study’s methodology was flawed.

There Were 4 Red Flags Here:

Monday Motivation - Fat Loss

1)      Questionable exercises and volume – Study participants did only 3 circuits (termed “sets”; very confusing to gym rats, who’d say it was really 24 sets in total) of resistance training on 8 machines, 8-12 reps per machine, 3 days per week. While I have no problem with the rep range or training frequency, if you’ve hit the weights much yourself, you’ve probably already spotted the problem. Circuit training typically does not contain all compound movements (those requiring movement in more than one joint to complete).

While it’s certainly better than nothing, it’s a tiny fraction of what most trainers would suggest for a muscle building / fat loss program.  If study participants spent half their time doing isolation movements like leg extensions or arm curls, well, those are kind of time wasters. It didn’t say in the documentation I read what those 3 “sets” consisted of, except that they “targeted all major muscle groups” Even if they were all squats, bench presses, and power cleans, that’s about half a workout shy of a load.

Additionally, what most reports on the Duke study fail to mention is that the subject s didn’t even begin using 3 circuit routines until study week 5, electing to “build up” from a 2 circuit routine before then!

2)      The cardio group did 12 miles per week at 60-80% VO2. Assuming (Yes, I know what happens when you do that!) they ran 12 miles a week, that’s not a great comparison, running 12 miles vs doing  9 circuits of something (after wk 5). Likely because free weight power cleans and other compound movements aren’t often (or easily) performed by untrained individuals, machine weight apparatus was used. Eschewing free weights rendered the resistance training even less effective.

3)      No metabolic rate analysis. Despite the study’s claims to see what was more effective at fat loss, when examining resistance training’s primary benefit for sustained fat loss, basal metabolic rate increase, mostly ignored it: “Resting metabolic rate, which determines how many calories are burned while at rest, was not directly measured in this study” They failed to measure Exercise Post Oxygen Consumption (EPOC) or any other parameter that could impart some insight here? Really??? WTF, Chuck?

4)      Didn’t restrict calories to what most would recommend for fat loss. At 2,100 daily calories, the study calorie counts were on the stout side for obese folks trying to shed fat. Despite my love of all things culinary, fat loss is 80% diet and 20% exercise. The study participants would have fared better had calories been more restricted.

Why didn’t the Duke researchers enlist some certified personal trainers to design a fat loss weight training program, instead of choosing  just  9 weekly circuits? Why, indeed? Yes, the study authors all have advanced degrees, but maybe some personal training certificates would have been a better idea.

Just my .02C, of course…. What do YOU think?