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- Alex Hutchinson (@sweatscience)
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A new study in the American Journal of Physiology revisits a very familiar topic — cardio versus weights — to determine which is better for reducing dangerous visceral and liver fat. A total of 155 subjects completed one of three eight-month training programs:
- Aerobic (AT): ~12 miles per week at 75% VO2max;
- Resistance(RT): 3 days a week, 8 exercises, 3 sets of 8-12;
- Aerobic/resistance (AT/RT): both the above programs combined.
At the end of the eight months, they used some pretty sophisticated tools to measure the outcomes, including CT scans to measure levels of visceral and liver fat. Here are some of the key outcomes:
And here’s how the researchers sum up the findings:
First, a resistance training program–even a very substantial one–did not significantly reduce body mass, visceral fat, liver fat or ALT liver enzyme levels. RT also did not reduce total abdominal fat, nor did it improve fasting insulin resistance. Second, in contrast to RT, a typical vigorous AT program resulted in significant reductions in visceral fat, liver fat and abdominal subcutaneous fat, and also led to improvements in circulating ALT and HOMA (fasting insulin resistance).
The results aren’t too surprising: as the researchers note, this particular aerobic training program likely burned about 67% more calories than the resistance program. It does seem a bit strange to me that adding resistance training to the aerobic training seems to make things worse rather than better — but the overall analysis in the paper says that AT and AT/RT are statistically indistinguishable. In other words, the weights add nothing. Don’t get me wrong: weights are useful for a lot of things, and this study was only testing a few specific outcomes. But on those outcomes — and they’re very important ones, particularly if you’re overweight — cardio trumps weights.
As always this is som important to emphasize foro recreational running. The problem with these insights is that the idea we got to keep on running impregnates our thinking. So much and so deeple engrained is the idea that if anyone wants to become a faster runner (s)he feels (s)he has to abandon the idea of sacred health, because than strengthtraining and plyometrics gain importance and takes time away from the times atletes used to run.
Did they control caloric intake and or diet?
It shouldn’t be news to anyone that cardio burns more calories than weight lifting. One of the points of weight lifting while cutting is to preserve muscle mass. I remember the first time I tried to get thinner and after a week I saw my chest look like a 10 year old girl. The whole experience got me interested in what is the right way to loose weight.
If they did not control calories , then they only shown that a calorie deficit causes fat loss. (aerobic training program likely burned about 67% more calories than the resistance program )
No way is that a substantial RT programme! And most of the RT exercises were on machines. Methodologically flawed, poor study.
Since so much of the benefit in resistance training, especially for untrained individuals, is the neuroendocrine response, I would rather see a study where they compared aerobic training with a resistance training that included major barbell movements (bellow-parallel squat, shoulder press, bench press, deadlift) and maybe some type of vertical or horizontal pull (pull-ups or row). I don’t have access to this paper, but I would bet a lot of money that the resistance training program they used included machine-based exercises like leg extensions and curls, which we know provide much less of a neuroendocrine response, if they provide one at all.
@Michal: “It shouldn’t be news to anyone that cardio burns more calories than weight lifting.”
Agreed — but unfortunately it IS news to many people.
@Morris: “If they did not control calories , then they only shown that a calorie deficit causes fat loss.”
No, they showed that aerobic training preferentially attacks visceral and liver fat, which are the most important in terms of health outcomes. Resistance training, on the other hand, ONLY affected subcutaneous fat loss, which is important for how you look but far less important for your health. This is a significant and novel result.
@Spencer: “No way is that a substantial RT programme!”
And you’re under the impression that jogging 12 miles per week is a “substantial” aerobic program? Both exercise regimes were appropriate for the study population, which was sedentary, overweight, high-cholesterol, and up to 70 years old.
Wow! This takes the wind out of the sails of the segment of the fitness industry that eschews cardio as a waste and at worst something that will kill you if you do it too much. Chronic Cardio Kills! You mean people actually have to work at getting their heart rate up other than just lifing a few barbells for a few minutes/week and barely breaking a sweat.
Did they measure changes in VO2max in the paper?
Alex, I still think you can’t dismiss the diet to make the conclusion that RT doesn’t help reduce visceral fat, even if you consider the combined group. For one, from my experience, both types of exercises seem to alter my hunger response. I would have added a control group: no exercise but only equivalent reduction in calories, and for the RT and AT groups I would have compensated diet to make it equivalent to the RT+AT calorie deficit.
@AG: You’re right that different forms of exercise could influence appetite in different ways. But in the end, aren’t we most interested in the result? In the real world, if a doctor or a personal trainer “prescribes” an exercise program, they don’t also have the luxury of perfectly controlling changes in caloric intake.
In fact, I’d say the study result would have been much WEAKER if they’d controlled dietary intake. Because then we’d say “Oh, well, it was an interesting result, but in reality whatever changes we observe would be offset by changes in appetite.” With this study, we see what actually happens using those two very typical exercise programs under real-world conditions.
@alex
I heard that subcutaneous fat is beneficial and cancels some of the effects of visceral fat. There was even an article which stated that big bottoms can be healthy.
It would be interesting to know if incorporating HIIT would make a big difference in those health markers. The concern is with visceral fat which is invisible (hidden under your six pack muscles) and is hard to distinguish from your organs, abdominal muscles, and ingested food and water from the outside.
Don’t we feel more relaxed after cardio than after weight lifting?
Ok, yah, but…
While cardio will definitely burn more calories that weight training while your doing it, in the long run weight lifting is also very important for weight-loss because muscle, on its own, burns more calories than fat. So even when you are resting, you are burning more calories.
That being said both cardio and weight training are loads better than doing repeated reps of potato-chip to mouth while watching TV, and watching diet is important. Personally, I just finished RT and now I’m going to go for a walk, giving that if I tried to run my circular body would pop my knees like bubble wrap.
@Andrew: Ok, yah, but… how do you explain the outcome of this study? If weight lifting is so awesome for burning calories because you’re burning more calories while you’re resting (a claim that is made over and over again with little clinical evidence to back it up), how come the resistance training group in this study did so poorly in losing weight?
the study cited did not control the food intake of the subjects. Resistance training stimulates anabolic states which can increase someone’s level of hunger. If the individuals were not on a strict caloric level, then the amount of fat gained or loss is essentially random. Physical activity is less of a catalyst of whether or not fat is lost than diet.