Cardio is an abbreviation of 'cardiovascular' and that literally means 'relating to heart and blood vessels'. Cardiovascular training, or simply 'cardio', means any form of training that increases the heart rate.

Something more practical: any form of training aimed at burning fat and/or improving conditions. This can be walking, cycling, or swimming, but also rope jumping, High-Intensity Interval Training (HIIT), or circuit training. Cardio is therefore not a synonym for endurance sports. 

What is cardio

Is cardio necessary? 

Everyone has their own reasons for doing cardio, but most of the time the (main) goal is fat loss. Now doing cardio is not strictly necessary to burn fat. A calorie-restricting diet can, in principle, suffice. Nevertheless, cardiovascular training offers the necessary advantages. To what extent these outweigh the disadvantages, which also exist, we assess in this article. 

Benefits of cardio

Disadvantages of cardio

Makes dieting easier (you can eat more) Makes you hungry (compensating food)
Stimulates active metabolism Becomes less effective over time
Increase the thermogenesis Increases cortisol ('stress hormone')
Increases insulin sensitivity Frequent and/or frequent cardio can be at the expense of muscle mass
Improves sleep quality  
Compensates for social eating and drinking moments  
Improves condition  
Has various health benefits  

Cardio for beginners