There is a recent push in the fitness industry to limit the amount of cardio you do if your goal is to gain muscle. But how does this affect your ability to lose fat?
A recent study from the University of South Wales looked at the ability to lose fat through strength training alone. The study showed that we can lose up to 1.4% of our entire body fat through strength training.
This was a systematic review and meta-analysis looking at existing evidence. Dr Hagstrom and team looked at 58 research papers that studied body fat measurements in strength training programs. Over 3000 participants were studied, and the programs on average were 45-to-60-minute strength training sessions per day with an average of 2.7 days of training per week. The programs lasted an average of 5 months and the average participant lost 1.4% of their total body fat over this time. Of note, the majority of the participants did not have previous weight training experience. These numbers are similar to fat loss results for people doing aerobic or cardiovascular training alone. The study did not look at the variables of exercise (volume, intensity, frequency).
One reason many do not feel that strength training leads to fat loss is because they often will not see a significant change in their weight. In cardiovascular training, you will often see consistent changes in weight loss as long as your calorie intake is controlled. With resistance training, you will often be adding muscle and even though you may be losing body fat, you will not see much change on the scale.
The ability to lose fat and gain muscle at the same time is a difficult argument to prove, but especially with beginners, it appears this can be possible with strength training alone. If you have been training for some time, it is more likely that you will need to choose one or the other and adjust your dietary intake accordingly. But if your goal is simply to cut (to lose fat), this is possible simply through resistance training and a caloric deficit, and you will likely maintain your lean muscle mass much more effectively than through a cardiovascular program.