“Overfat”, that’s a term scientists use to refer to obese, but more importantly over- or even normal-weight people who are still carrying exuberant amounts of body fat around. In a recent meta-analysis, James E. Clark from the Manchester Community College tried to figure out, which of the significant numbers of means of methods to alter body composition, and metabolic issues that are available for the adult who is overfat is the “best” one.
In his review, the scientists focused on comparing changes from treatment program for adults who are overfat based on analysis of aggregated effect size (ES) of inducing changes from 66-population based studies, and 162-studywise groups.
Clark’s analysis of this large dataset yielded both, obvious and less obvious results. The realization that “a hypocaloric balance [=dietary restriction] is necessary for changing body composition” (Clark. 2015), for example is hardly surprising.
What may be surprising, though is the fact that the available evidence indicates that the size and effectiveness of the caloric deficit “does not equate with the effectiveness for body compositional changes, or any biomarkers associated with metabolic issues” (Clark. 2015). In other words: It’s not the guy or gal who diets the hardest who will lose the largest amounts of body fat.
As the data in Figure 1 goes to show you, the combination with exercise is generally beneficial. In view of the fact that being “overfat” is also associated with being undermuscled, there’s yet no reason to doubt Clark’s conclusion that
“resistance training (RT) was more effective than endurance training (ET) or combination of RT and ET, particularly when progressive training volume of 2-to-3 sets for 6-to-10 reps at an intensity of ≥75% 1RM, utilizing whole body and free-weight exercises, at altering body compositional measures (ES of 0.47, 0.30, and 0.40 for loss of BM, FM, and retention of FFM respectively)” (Clark. 2015)
Now, while this may still be in line with at least some of the mainstream recommendations, Clark’s observation that the RT regimen was also more effective at reducing total cholesterol (ES = 0.85), triglycerides (ES = 0.86) and low-density lipoproteins (ES = 0.60), as well as at reducing fasting insulin levels (ES = 3.5) than endurance training or endurance training and resistance training in combination emphasizes how much of a game changer (intense!) resistance training can actually be.
Avoid black and white thinking! Despite the fact that the meta-analysis at hand shows on average that interventions that focus on diet + resistance training are the most effective ones. It would be haphazard to conclude that doing a moderate amount of cardio would be counter-productive. If you use it, to eat more, it may in fact impair your results. If you go for a 20-minute jog at a moderate pace thrice per week, though, this is neither going to burn away muscle mass, nor stalling your fat loss. As discussed below, the lack of additional effects of combined training in the meta-analysis at hand may well be caused by factors that have nothing to do with the often-heard-off ill effects of moderate intensity cardio.
There’s thus just one thing we still have to address: Why is doing both, cardio and resistance training not more effective? Well, the answer may be hidden in the study design, where the combination training rarely complied to the previously outlined rules of a high intensity, progressive, high volume resistance training workout with free weights. In addition studies that met these criteria, such as Cuff et al. (2003), for example, didn’t measure the body composition of their female subjects and focused on weight changes, exclusively. In the exceptional studies that had both a sensible resistance training regimen and comprehensive analyses of body composition in place, on the other hand, suggest that the lack of benefits in the combined training analysis of Clark’s study may be a statistical phenomenon.
Bottom line: If you still need material to convince your significant other that hitting the weights is not only more time-efficient and less daunting than hours on the treadmill, but also more effective when it comes to improving his/her body composition and/or health, I’d suggest you print this article and pin it on your fridge.
Eventually, though, the article has another, even more important message than “resistance beats cardio training”. Which one? Well, there is “no relationship between any treatments effectiveness for inducing acute changes in energetic balance with the effectiveness for induced responses to body composition or biomarkers of health from said treatment program” (Clark. 2015). A revelation that reinforces the idea that our individual body composition is not a function of energy intakes vs. expenditure. The effects of metabolic stress, which is obviously greater for resistance and HIIT training (compared to steady state, the HIIT studies in the meta-analysis yielded better results, too), on the other hand is still underappreciated by both practitioners and scientists of who James E. Clark is one of the first to conclude that the “focus of treatment should be on producing a large metabolic stress (as induced by RT or high levels of ET [don’t overdo it on “cardio”, though | learn why]) rather than an energetic imbalance for adults who are overfat” (Clark. 2015) | Comment on Facebook!
- Clark, James E. “Diet, exercise or diet with exercise: comparing the effectiveness of treatment options for weight-loss and changes in fitness for adults (18–65 years old) who are overfat, or obese; systematic review and meta-analysis.” Journal of Diabetes & Metabolic Disorders 14.1 (2015): 31.
- Cuff, Darcye J., et al. “Effective exercise modality to reduce insulin resistance in women with type 2 diabetes.” Diabetes care 26.11 (2003): 2977-2982.
- Donnelly, Joseph E., et al. “Effects of a very-low-calorie diet and physical-training regimens on body composition and resting metabolic rate in obese females.” The American journal of clinical nutrition 54.1 (1991): 56-61.