Cardiovascular exercise is a key part of most workout regimens, whether you are a dedicated fitness enthusiast or just trying to live a healthier lifestyle. Any exercise that raises your heart rate and keeps it up for an extended period of time can be considered cardiovascular exercise (or cardio). This could include more traditional forms of steady-state cardio like running and cycling, or increasingly popular workouts like HIIT.
While cardio exercise is often related to weight-loss and burning calories, there are tons of benefits that come from getting your heart pumping, like:
- Strengthening your heart and lungs
- Reducing risk of diseases related to high blood pressure and cholesterol
- Naturally boosting energy
- Helping to improve the immune system, making it easier for your body to fight off illness
- Improving mental health
Incorporating cardio workouts into your routine is a great way to feel your best. For some, steady-state cardio exercise is a staple in their workout routine, but others have turned to High Intensity Interval Training (or HIIT) in recent years claiming it to be more effective and efficient.
HIIT workouts utilize intervals of high-intensity exercise and rest
“HIIT” is short for “High Intensity Interval Training”. A typical HIIT workout takes about 20-30 minutes and alternates between high intensity anaerobic exercise and low intensity rest periods. During high intensity periods, you should be at about 85-90% of your maximum heart rate capacity, or around a 9-10 of your perceived exertion. These high intensity periods can last anywhere from a few seconds to several minutes at a time, and are meant to push your body to the limit.
HIIT workouts give you all the benefits associated with cardiovascular exercise, but in half the time. These workouts can also easily be done in tight spaces or indoors, making HIIT incredibly accessible. However, with a high intensity workout like HIIT, there is an increased risk of overtraining and injury.
If you are just starting your fitness journey, it’s a good idea to start with steady-state cardio to establish your own personal limitations. A personal trainer can also help you learn how to safely and effectively incorporate HIIT into your workout regime.
HIIT training is highly customizable to fit a variety of fitness goals
There are many types of HIIT workouts ranging in length, difficulty, and purpose. Adding weights to your HIIT workout can help build muscle, while short interval practices like Tabata increase VO2 max. Sprint HIIT workouts are great for runners, and there are even HIIT workouts focused purely on improving endurance.
HIIT requires less time but more intensity
While HIIT and cardio have many similar benefits, the way they impact the body is different. In order to understand these differences, it is important to know how aerobic and anaerobic exercises work.
- Aerobic exercise promotes the circulation of oxygen in the blood. This means that your muscles will have all the oxygen needed to perform the exercise over an extended period of time. Traditional, steady-state cardio workouts are aerobic.
- Anaerobic exercise requires more oxygen than your body is able to provide. The body uses a process called glycolysis to turn sugar into energy during anaerobic workouts like HIIT.
When it comes to differences between the two forms of cardiovascular exercise, duration and payload are key. Because the body is burning calories quicker during anaerobic exercises like HIIT, workouts can typically take less than 30 minutes. HIIT workouts are difficult. They require you to push your body as hard as you can. While these types of workouts are not for everyone, HIIT can be extremely rewarding and allows you to cut down the time needed for cardio.
On the other hand, traditional cardio requires more time at a lower intensity. This isn’t necessarily a bad thing, as there is less stress on the respiratory and cardiovascular systems during these workouts. Rather than exercising at 85-90% of your maximum heart rate capacity, traditional cardio methods require about 60-70%. Steady-state cardio like jogging or swimming can be just as effective as HIIT when time and effort are consistently put in.
HIIT helps you burn (a few more) calories even after your workout has ended
After high-intensity anaerobic workouts, your metabolism can remain elevated for hours. This means that you can continue to burn calories while you are not working out for a short time period following HIIT. You may have heard this phenomenon referred to as the Afterburn effect, or excess post-exercise oxygen consumption (EPOC) effect. While there is evidence to suggest that the afterburn effect does occur, most people will only burn around 250 additional calories.
The bottom line: HIIT and steady-state cardio are both effective
When it comes to cardio for weight loss and health, consistency is the number one aspect of success. If you prefer shorter, more intense or varied workouts, HIIT might be for you! If jogging or other less intensive activities are more your style, then there is nothing wrong with sticking to traditional cardio workouts. It is most important to find something that you like and stick with it in order to meet your fitness goals, whatever they may be.
Try HIIT if:
- You are experienced in moderate to high-intensity exercise.
- Your resting heart rate is below 60 bpm
- You need shorter workouts to fit into a busier lifestyle
- You like mixing things up and trying different workouts and exercises
Try steady-state cardio if:
- You are new to working out or have not worked out in awhile.
- You prefer lower intensity workouts or have been advised by a medical professional to avoid high-intensity exercise
- You are recovering from injury
Can HIIT replace strength training?
HIIT workouts can be great for building muscle, especially when weights or resistance training is incorporated. By burning fat and promoting muscle growth, HIIT can increase your metabolism and help with muscle definition and toning. However, you will not see the same muscle gains doing HIIT alone.
For a full body workout routine, try doing both HIIT workouts and strength training. Not only will you get the full benefits of both, but they can complement and enhance each other as well. HIIT improves your overall endurance, flexibility, and stamina, allowing you to lift more and reduce your risk of injury. At the same time, strength training helps to build lean muscle which can actually improve the afterburn effects that you get from HIIT.