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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.