Cardio does not kill your gains. It can actually help you build muscle faster. here’s how : cardio improves your work capacity, you can work faster with less rest required between heavy sets. Meaning you can lift more weight in a workout because you have the aerobic capacity that allows it. When you have better oxygenation better oxygen delivery, you can push harder during the reps of your weightlifting sets. Maybe you get another two or three reps. Cardio will actually boost your appetite. You