Does aerobic exercise interfere with muscle gains from weightlifting?
If you’re training for an endurance event like a marathon, when you might run 60 miles or more per week, you’ll almost always see a decrease in your muscle mass. For most of us, who do more moderate amounts of physical activity, there will be minimal, if any, loss in muscle mass — so there’s nothing to worry about. If you do plan on lots of aerobic exercise and are concerned about losing muscle, try starting with 20-30 minutes of moderate aerobic exercise (at 50% to 70% of your maximum heart rate) two to three days per week, and see how it goes.
