When I think of cardio, I used to think about running, cycling, swimming, maybe rowing, and activities of a similar manner. Cardio was narrowly defined within these types of continuous activities. What I’ve come to realize is although I heard the word “cardio” thrown out a lot, I didn’t really know what this word actually described. First, “cardio” is short for cardiovascular and for those of you who are still in the dark, cardiovascular is defined by the Merriam –Webster dictionary as “of, relating to, or involving the heart and blood vessels” (1) and “used, designed, or performed to cause temporary increase in heart rate (a cardiovascular workout).” (2) By these definitions, it’s obvious why the activities I listed above are only a very narrow allocation of what cardiovascular entails. My first awakening was to expose myself to the breadth of what cardiovascular workouts actually includes.
Secondly, before receiving an education in personal training, I didn’t realize how misguided the question “is cardio better for weight loss?” is. Like many, I used to be one of those people who believed, in order to lose weight, I need to do a lot of cardio. But now, when I am asked this question, I am often perplexed on how to answer. For one, there are so many types of cardiovascular activities, so asking whether cardio is better for weight loss also depends on which type of cardiovascular workout. Secondly, if weight loss is the only goal, there are other ways-- like nutrition, to help achieve such goals. I now understand that this question is more an indication of the lack of knowledge in regards to weight loss and working out in general, which is why someone would be asking such a question. But, here are some things to remember:
# 1 - Not all cardio is made equal.
Let’s outline the two main types of cardio. There is aerobic and anaerobic training, which can be further classified as steady-state training and high-intensity interval training. To put it simply, the differences in cardio training depends on the level of oxygen and where energy is derived from.
Steady-State Training/Aerobic Training:
Aerobic means in the presence of oxygen
“Characterized as large-muscle, rhythmic activities (e.g., walking, jogging, aerobics, swimming, cross-country skiing),”1 which typically recruits type I muscle fibers (3)
Is performed at 50-65% of maximal aerobic capacity (at an RPE [rate of perceived exertion] of 3-5)
“…can be sustained without undue fatigue for at least 20 minutes.” (1)
Is typically performed in one consistent bout without rest intervals
High-Intensity Interval Training/Anaerobic Training:
Anaerobic means without the presence of oxygen
Tends to include explosive movements, which typically recruits type II muscle fibers (3)
Is performed at 80-95% of maximal aerobic capacity (at an RPE [rate of perceived exertion] of 7 or higher) (2)
Can’t be sustained for extended periods of time (about 30 seconds to 3 minutes) (2)
Includes bouts of work and recovery intervals, which are equal to or longer than the work time (2)
# 2 – There is research to support which cardio is better for weight loss. This is one example.
Researchers at the University of Wisconsin, La Crosse, ran a study which concluded high-intensity exercise equals to a higher calorie and a higher total number of fat calories burned. (1)
“Subjects performed two 30-minute bouts of exercise: a relatively low-intensity bout and a relatively high-intensity bout.”
“The results, show that for the low-intensity exercise, subjects burned a total of 240 calories, with 96 of those calories (41%) coming from fat.”
“During the high-intensity bout, a total of 450 calories were burned, with 108 of those calories (24%) coming from fat.”
Therefore, although there was a higher percentage of calories from fat in people who performed the low-intensity bout, but notice that the total number of calories burned was less than during the high-intensity trial. This data shows that although in terms of percentage, more fat was burned during the low-intensity bout, more calories were burned during the high-intensity bout and weight loss is about how many calories you burn in total, regardless of the source of those calories.
What’s important to understand when it comes to weight loss is that there are multiple ways to achieve this goal. Whether it’s through nutrition or strength training, if weight loss is the only goal cardio is not actually necessary. What broadens the need for cardiovascular activities are if the goal is more than just weight loss and is more a health goal. Unfortunately when it comes to weight loss there are a lot of fad theories and products out there! Weight loss is a much more complicated topic than meets the eye, especially when you also factor in the various unique factors which impact an individual’s capacity for weight loss. There’s no blanket rule book that’s right for everyone. It is the responsibility of the individual to explore the different avenues towards weight loss and to commit to a lifestyle change that works for them.
Green, Daniel J, and Cedric X Bryant, editors. ACE's Essentials of Exercise Science for Fitness Professionals. American Council of Exercise, 2010.
“High-Intensity Interval Training.” ACE Fit | Fitness Information, ACE | The American Council on Exercise, www.acefitness.org/acefit/fitness-fact-article/3317/high-intensity-interval-training/.
Jr., Paul Hovan. “Is Cardio Really the Secret to Fat Loss?” Www.ISSAonline.edu, ISSA, 10 Aug. 2016, www.issaonline.edu/blog/index.cfm/2016/is-cardio-really-the-secret-to-fat-loss.