I’ve heard that if one runs too much that one will start to burn off muscle? I do have fat to burn so will muscle only be burned after all my fat is gone? I want to lose some belly fat while trying to build muscle. If I run after a workout do I have to worry about running or doing the eliptical too much? I usually lift for 30-45 min then run for 20-30 min.
It’s more that long distance running will hinder your muscle growth goals as opposed to your body using you muscle for fuel. Running for 20-30 minutes however probably shouldn’t be a problem.
Running for longer periods of time however, does tend to break down muscle, it is better instead to do high intensity interval training like sprinting, which will actually help you build muscle and increase your endurance at the same time. Just think about the marathon / cross-country runners vs. the sprinters you see in the Olympics.
Here’s a clear article: