Cardiovascular workouts are designed to balance three factors for maximum effectiveness and safety: frequency, intensity, and duration. You will also need to include a warm-up period before you enter the target intensity period of your workout and a cool-down period before the end of your workout.
What Is Cardio Exercise?
Common cardio exercises are brisk walking, running, cycling, swimming, rowing, and cross-country skiing. In the gym, cardio machines include the treadmill, elliptical trainer, stationary cycle, stepping machine, rowing machine, and ski trainer.
Cardiovascular exercise raises your heart rate and breathing rate into the moderate-to-vigorous intensity level for 10 minutes or more.
Exercises that are done primarily to build strength, such as lifting weights, using weight machines, resistance exercise, and core workouts, are usually not considered to be cardio exercises. They are intended to challenge strength, not cardiovascular endurance.
However, you can structure certain weightlifting workouts to raise your heart rate and gain a cardio benefit. For example, a superset workout provides little rest in between exercises. As a result, your heart rate stays elevated throughout a series of complex exercises.
Warming Up and Stretching
Warming up before the more intense portion of your workout gets the blood flowing to your muscles and loosens you up. This is essential; you should not just start your workout at full effort.
Traditionally, the guidelines were to stretch the primary muscles to be used in the workout during your warm-up. There are several schools of thought on the use and effectiveness of stretching, with some experts advising a dynamic warm-up but not static stretches before cardio exercise. The standard advice:
- Do a 5- to 10-minute warm-up at low intensity (50% to 60% of your maximum heart rate) to prepare your muscles for exercise and steadily raise your heart rate.
- Do whatever activity will be your workout for your warm-up. If you are walking or running, start at an easy pace that puts you into this low-intensity heart rate zone—where you can still carry on a full conversation.
- Next, stretch the muscles you will use in your workout. They are warmed up and may benefit from flexibility stretches or drills specific to the muscle groups you will be using in the workout.
After you have completed your workout in your target heart rate zone, you should cool down with five to 10 minutes of lower intensity activity (again, 50% to 60% of your maximum heart rate. Traditionally, you would end your workout with gentle stretching of the muscles used in the workout. This is no longer universally recommended, but you can do it if you wish.
Frequency of Cardio Exercise
The minimum recommended amount of cardiovascular exercise is 150 minutes per week of moderate-intensity aerobic activity, 75 minutes per week of vigorous aerobic exercise, or a combination.1 Exercise sessions should be spread throughout the week.
The American College of Sports Medicine recommends cardiovascular exercise three to five days a week for most people.
To give your body time to build and repair muscles, alternate intense or long cardio exercise sessions with a day of rest or easy exercise. An “easy day” might mean a slower walk, stretching, or yoga.
Duration of Cardio Exercise
How long should you exercise in each exercise session? For cardiovascular benefits, aim for 20 to 60 minutes in your target heart rate zone, apart from the time you spend in warm-up and cool-down. At this duration, your body burns through its available glycogen energy and begins to burn stored fat.
You will still burn calories if you exercise for less than 20 minutes in your zone. But the best fitness benefits come from spending 20 to 60 minutes in the aerobic zone.
Cardio Exercise Intensity
When beginning a fitness program, concentrate on adding duration with good posture and form before you boost the intensity of your workout. If you are walking for your workout, increase the number of minutes walked (by no more than 10% per week). Once you are walking comfortably and with good posture and form for 60 minutes at a time, then work on increasing intensity by adding speed, hills, or intervals.