The question is, what is your primary goal here? Do you want to build muscle mass, and is it something you struggle with metabolically?Not everyone fits into this category, and are more likely to put on weight easily. We have evolved into humans of convenience now since all foods are available when we need them.Every single kind of cardio will have either a detrimental effect on your muscle gain, or it won’t cause any issues at all. Here, Iām speaking from my own experience, as Iāve been doing the wrong and right things for years.Ā If I intend to put on muscle mass, my primary aim is to stay away from any vigorous cardio. What do I mean when I term some form of cardio āvigorous.ā That is anything from long duration and exhausting cardio, running for hours on the treadmill, to doing something that depletes your energy levels completely.Ā I can sympathise with this, as I had every intention of putting on muscle, but still did my very high-intensity cardio. That would completely negate all the efforts I made with my weight training completely! Not all of us are built in a way, that we can do effective weight training, get those gains, and do hardcore cardio too. It just doesn’t work that way. Why do I know this? Because itās a tragic situation, I got myself into when I began my bodybuilding journey. I was still stuck in the old school mindset, of cardio being king to weight loss. Itās actually not, and it can do a lot of damage to your body, immune system and also your bone density.Ā Thatās not to give you the idea that all cardio is bad and will eat away at your muscle mass.Ā On the other side of the spectrum, we have steady-state, which is very light and doesnāt increase your heart rate a lot. This is something like walking or even riding your bike at a slow pace. You can keep up with this for a while; it doesnāt exhaust you, leaving you feeling more invigorated. Perhaps Iām over exaggerating a bit, but this is how I feel after I have my daily walks in the park when the sun is shining, and the air is fresh and clean.Ā This form of cardio should not negate your muscle-building efforts, and I find I can do this several times a day, before, during or after cardio. It doesnāt cause any problems. In fact, I like to warm up this way, before weight training, and then cool down and flush out the lactic acid in my muscles after a workout. On leg day, I can be extremely uncomfortable, and having a long walk on the treadmill, where Iām producing long strides, helps to clear my whole legs’ stiffness and soreness.Ā There is a saying that the best time to do cardio is on days when you arenāt lifting weights. That is very accurate to an extent but only applies to those who are doing intensive cardio. If you are very fixated on building as much muscle mass as possible, then do your cardio on a completely different day to your weights so that you can put all your energetic efforts into those lifts. For all other humans, it really doesnāt matter.Ā Just keep in mind that youāre in the gym to achieve your goals, stick with the plan, and make that form of exercise your main priority. Everything else should be a secondary activity.