Time for everyone's favorite topic. Cardio! Okay maybe not favorite. Infamous is probably a better word for most people's view of cardio. There are so many memes dedicated to the dread of cardio that it's a wonder anyone gets out of the chair when they're not lifting! Powerlifter antics aside, let's get down to business.
Where to Start Your Cardio Journey
If you were like me you started out very heavy, and if you're more like me, you spent a large portion of your life laying in bed or sitting all day. Your work capacity is EXTREMELY LOW. Normal day to day activities are much more exhausting for you than for others. Getting out of breath when walking up a single flight of stairs isn't exactly healthy. I think we're all aware of this, but it's also the reason I believe that if you have spent a significant portion of your life sedentary you should focus PRIMARILY on cardio and other low intensity exercises when you begin your fitness journey.
This is related to why I suggest losing weight first before taking up exercising. Being overweight is hard on the joints. Walking is enough to worsen the problem if you're heavy, you want to start lighter so you have less of a possibility of creating problems. But after your weight loss cardio is going to help you get into shape by improving how efficiently your body uses oxygen, creating new blood vessels and improving your blood flow, and helping to reduce your heart rate and blood pressure.
If walking for long periods isn't something you're used to then it's the first place you should start. Walking counts for exercises if it's something you rarely do. Even if you can barely make it to the mailbox or down the block, start small. If you have a sidewalk, next time you go on a walk, count the blocks in the sidewalk and walk a bit further. Over time you'll almost not realize that you're at a point where walking is something that you can do easily. Once you're there you can introduce some running, when I lost weight I would run the last bit of my walking route, and over time increase the amount of running until I could run the entire route. If you just have one block to walk around, doing laps is a nice idea.
Benefits of Cardio and Strength Training
I see a lot of recommendations against running for individuals who strength train, and I don't see any validity with this. The only way it will interfere with muscle gain is if you're doing cardio two times a day or for multiple hours per day. I've built quite a lot of strength while also having one and two manual labor jobs that involve a lot of cardio and medium intensity exertions. I think avoiding cardio for fear of "lost gains" is an excuse. An understandable one; cardio isn't exactly fun— It's easier if you're on your feet physically moving through space (or well, more realistically on land or floors). Being in place on a treadmill or elliptical does get boring even with music or your phone. The bonus points of working a manual labor job for me is that I make money while doing my cardio!
Cardio is going to help you build aerobic capacity which, despite what people may think, will improve your performance in the gym. High intensity exercise like strength training is anaerobically fueled yes, but the energy system for ATP-PC can be "re-fueled" more quickly by the aerobic system when you do cardio to improve your body's aerobic capacity, facilitating better recovery. The creation of new blood vessels and increased efficiency of oxygen utilization by the body caused by low intensity cardio will create better blood flow and make it easier for the body to put insulin and nutrients into the muscles and clear waste products from them. This is good for your gains, guys! And if nothing else, the increased caloric expenditure from low intensity cardio will allow you to get away with consuming slightly more calories for the same amount of weight loss when cutting. If you're on a 500 calorie cut, you can reduce food by 300 calories and introduce 200 calories burned by cardio, for example.
I thought about writing about calisthenics when I began writing these articles. I wasn't sure if they should go in the Cardio or Strength Training portions. I think it depends on your body weight and absolute strength when performing them. For example when I did a lot of calisthenics, I was 240lbs and could barely do a couple pushups. Surely that's high intensity if two reps is my max! Now I can bang out TWENTY push ups *easily*. I think it comes down to where you are in your fitness journey, so calisthenics is something I won't talk too much of here. I might save that discussion for a future article.
The improvements from cardio are a bit nebulous in comparison to diet and strength training. It's most significant effects are how "out of breath" you get in daily life, which isn't always the most obvious thing particularly for those who are more sedentary outside of the gym, or for those who work physically demanding jobs that very with their workload day by day. I would recommend doing some type of cardio every day to keep a bare minimum. You could do a completely different type of cardio every day; it doesn't demand the same type of neural adaptations that barbell training does.
A peculiar fear or dread for cardio was ingrained in me when I was morbidly obese. It was so exhausting just to get up and move around. Now I love moving around and couldn't imagine not doing so. It can really change your life to have that ability. So never take it for granted and get in that cardio!