Cardio is exercise that gets your heart working hard for a stretch of time — running, swimming, cycling, a dance class, skipping. Gyms and trainers use it as a noun (“I did thirty minutes of cardio”) and sometimes in front of another word (“a cardio workout”).

Cardiocardio這個字 is exercise that gets your heart working hard for a stretch of time指的是能讓心臟持續用力工作一段時間的運動 — running, swimming, cycling, a dance class, skipping像跑步、游泳、騎腳踏車、跳舞課、跳繩。Gyms and trainers use it as a noun健身房和教練會把它當名詞用（'I did thirty minutes of cardio'「I did thirty minutes of cardio（我做了三十分鐘的cardio）」） and sometimes in front of another word有時候也放在另一個字前面（'a cardio workout'「a cardio workout（有氧訓練）」）。

It is informal fitness English, cut down from cardiovascular, which means “about the heart and the blood vessels.” People contrast it with weights or strength training: one is for the heart and lungs, the other is for muscle.

It is informal fitness English這是健身圈的非正式用語，cut down from cardiovascular從cardiovascular縮短來的，which means 'about the heart and the blood vessels.'意思是「跟心臟和血管有關」。People contrast it with weights or strength training大家常拿它跟weights（重量訓練）或strength training（肌力訓練）做對比：one is for the heart and lungs, the other is for muscle一個練心肺，一個練肌肉。

It is not a doctor’s word for heart disease; cardiac lives in that hospital world. At the gym, cardio just means the sweaty, breathing-hard kind of exercise.

It is not a doctor's word for heart disease它不是醫生用來說心臟病的字；cardiac lives in that hospital world那個世界用的是cardiac。At the gym在健身房裡，cardio just means the sweaty, breathing-hard kind of exercisecardio就是指會流汗、喘氣的那種運動。