Cardio, like many celebrities, is famous and always in the media, but no one is sure what it is, what it does, and why everyone’s so crazy about it. When you think of cardio, what first pops into your head? Is it running or jogging? Or long boring sessions on a bike or elliptical or treadmill? There’s a lot of talk about doing “cardio,” but most people either don’t know what it means and what it does.
Part of the problem is that there isn’t a clear-cut and common definition of cardio. It would be a misnomer to refer to cardio as “anything that raises your heart rate” as this could include almost any activity other than staying seated. Working backward from cardiovascular fitness, we can arrive at a definition for what includes cardiovascular exercise.
Cardio is exercise that improves the body’s ability to deliver oxygen-rich blood to working muscles, and the muscles ability to use that oxygen-rich blood to produce energy. Basically, any type of training that increases the body’s ability to produce energy to accomplish movement-related tasks. In order to increase this ability, training principles inform us that this requires progressive overload, which means continually challenging one’s current fitness at regular intervals over time.
Let’s break this down even further. Cardio must raise the heart rate as a product of demand by the muscles for more oxygen in order to produce energy translated to movement. Although still somewhat vague, this definition can help determine what activities can be included under cardio. This could include what are traditionally suggested as cardio: running, biking, swimming. But can also include activities like strength training, tennis, and fencing.
Most importantly, cardiovascular fitness in one activity does not translate 100% to other cardio-based activities. For example, if you are a runner and try biking, you might be there sweating your butt off thinking, “I must need to do more cardio.” But remember, cardio increases your body’s ability to use the oxygen-rich blood to produce energy from the muscles. In the running to biking scenario, you’re using different muscles (that you haven’t trained specifically to do this), which has the result of your body needing to work harder than those muscles that you train regularly. This is why specificity of training is important!
Cardio has been linked to reducing the risk of a host of different diseases which is why it is one of the most promoted vs strength training. It also requires little to no equipment and no real knowledge to do it. Cardio may aid in weight loss, and strengthen your heart muscles, which means your overall health will improve and you’re more likely to live longer as a result. Winner winner!
Like all forms of exercise, cardio should be introduced slowly into your training program. Too much too soon can increase your chances of injury by putting too much strain on your muscles that don’t yet have the capacity to physically withstand what you’re demanding of them. Start by trying to meet the Canadian physical activity guidelines which suggest 150 minutes of moderate to vigorous cardiovascular activity per week in bouts of 10 mins or more.
Kristen Hansen, BA, CSEP-CPT, PFT-NAIT, NASM-CES, FRCms
SVPT Fitness & Athletics