There are two major types of cardio exercise, high-intensity interval training (HIIT) and low-intensity steady state cardio (LISS). To determine which form of exercise is right for you, you must first understand each of them.
High-intensity interval training is basically what it sounds like. It is when you train at moderate intensity levels for a short time and then switch to a burst of high-intensity exercise, alternating at predetermined intervals. For example, you may start with a 5 to 10 minute warm up of light jogging, followed by a 15 to 20-second sprint, pushing yourself as hard as you can. Once that 15 to 20 seconds has ended, you may walk for 60 to 90 seconds, or until you feel fully recovered. Repeat these 5 to 10 times, aiming to improve your capacity over time.
Low-intensity steady state cardio, on the other hand, is exercise at low to moderate intensity, or 50 to 65 percent of your maximum heart rate, for a minimum of 20 minutes. Examples of this type of cardio exercise can range from jogging or riding your bike to work instead of driving, to leisurely activities such as swimming or going for a brisk walk.
Which is Better? HIIT vs. LISS
In order to determine whether either HIIT or LISS cardio is the best option for you, you should know what your specific health goals are. If you are only looking for work outs to help you burn fat, LISS might be what you’re looking for. This is because HIIT is an anaerobic form of exercise that primarily burns carbohydrates for energy, with fat as a secondary source, while LISS cardio burns fat to fuel the body. That is not to say that HIIT exercises don’t burn fat because they certainly do. LISS is simply more focused toward fat-loss than HIIT.
If you are looking for a workout program to help you reduce your risk for type-2 diabetes as well as many cardiovascular diseases, however, HIIT might be the best option for you. HIIT promotes heart health, weight-loss, and improved cholesterol levels, among others.
To put it simply, LISS cardio is essentially a way to burn off excess fat, but it doesn’t have many benefits beyond that. HIIT, on the other hand, is a form of exercise that promotes a well-rounded, healthy lifestyle, while also reducing serious health risks. That’s why it is important to know what your fitness goals are before you get started.
Why HIIT Could Be Considered Superior
There is a multitude of things that make HIIT the superior choice over LISS. Not only is high-intensity interval training convenient exercise for busy lifestyles, but you will find there is a lot of flexibility in the types of work outs that you can do with HIIT.
HIIT does not have to take up your entire day is extremely beneficial for those of us who have a busy or fast paced life. In fact, you can fit it in early in the morning before you leave the house, during or before your lunch break, or really any time when you have a free moment.
Fortunately, there is also a wide range of exercises that can be done with HIIT. This is ideal so that you don’t feel burned out doing the same thing every time. It can be anything that gets your heart pumping while allowing you to go full force for a short burst of time. You can try sprinting, running, cycling, push-ups, squats, or even weights.
Health Benefits of HIIT
- Increased weight loss, sustainable fat loss, and reduced appetite. For starters, high-intensity interval training is the best way to not only lose weight but to keep it off as well. This is because HIIT is a form of exercise which promotes fat-loss over a period of time, even after exercise has ended. Additionally, this form of exercise is known to have an impact on several hormones. For instance, HIIT lowers the hormone that stimulates appetite, ghrelin, while increasing blood lactate and blood glucose levels, which hinders short-term appetite. HIIT also increases epinephrine and norepinephrine levels, which are hormones known for driving lipolysis, or the breakdown of fat.
- Increased Excess Post-exercise Oxygen Consumption (EPOC). On average, EPOC lasts anywhere from less than an hour after exercise to 24 hours after exercise. That’s a huge difference! This large range of time comes from the intensity, duration, and variances in the method of training. Research shows that EPOC lasts for up to 9 hours after 20 rounds of high-intensity exercise, separated by intervals of 2 minutes of rest.
- Possible prevention and reversal of type-2 diabetes. Research suggests that doing 2 to 3 HIIT sessions per week, as well as eating a healthy diet, can help prevent and even reverse type-2 diabetes. The effects on type-2 diabetes may be a result of lowered blood glucose levels, as a result of improved adipose and liver insulin sensitivity.
- Improves insulin sensitivity. Insulin sensitivity designates the cells ability to take in increased amounts of glucose while still functioning properly, and is sometimes referred to as glucose metabolism. Data shows that continuous use of HIIT over time, from varying lengths of 2 weeks to 4 months, can improve insulin sensitivity by 23 to 58 percent.
- Improves cholesterol levels. Sustained use of HIIT for a period of 8 weeks or more, along with a clear decrease in body fat, is required to see significant improvement in total cholesterol, HDL cholesterol, LDL cholesterol and blood triglycerides levels.
- Improves blood pressure. Research shows that 12 weeks of continuous HIIT can result in a noticeable decrease in both systolic and diastolic blood pressure, by anywhere from 2 to 8 percent lower. However, persons with hypertension or anyone taking hypertension medication are unlikely to notice a difference.
- Enhanced VO2 max output, and overall better heart health. Changes in VO2 max have been known to appear shortly after beginning high-intensity interval training. This may be because of the nature of HIIT, which is to exert yourself in short bursts, followed by lower intensity work outs. Doing so causes an increase in the volume of blood being pumped through your heart for each beat because the hearts muscles’ contractile capability is increased. Enhanced VO2 max output is a significant benefit of HIIT since low VO2 max is one of the early indicators of cardiovascular fatalities. Additionally, studies show that working out with high exercise intensity is more beneficial in improving one or more risk factors for coronary heart disease.
Drawbacks of HIIT
As long as high-intensity interval training is performed properly, there are no major risks associated with this form of exercise. However, there are still a few things you should look out for and consider when participating in HIIT.
- Occasional dizziness. Continuous changes in positions can cause dizziness, and in some cases, blood pooling in the lower extremities. To lower your risk, make sure that you stretch before hand and take your time when switching between high-intensity bursts and moderate intensity resting periods.
- Muscle soreness. Sometimes, doing too much too soon can lead to excessive soreness in the muscles and joints. Also, if HIIT is done incorrectly, with intense intervals lasting too long, it can potentially cause rhabdomyolysis, which is the breakdown of muscle fibers that poison the kidneys through the blood stream.
The Case for LISS Cardio
While there is a strong case for HIIT, you shouldn’t count LISS cardio out as it also has significant benefits. For one, LISS is easier for those who are just starting their fitness journey, while also being a great stepping stone to higher intensity work outs. Additionally, there are many exercises that you can do with this form of training, making LISS cardio enjoyable.
Low-intensity steady state cardio is excellent for those who are just beginning in their fitness goals. This is because it is considered the easiest of the two forms of exercise. Additionally, when you’re looking to gradually increase your workout intensity over time, LISS cardio is the perfect form of physical fitness to help you do so.
Low-intensity steady state cardio can also be fun. You don’t always have to go to the gym to participate in LISS cardio either. Many outdoor summer activities like bike riding, hiking, or even a jog around the block are sufficient enough for LISS cardio. Just be sure to monitor your heart rate or calories burned if your goals are weight and fat loss.
Health Benefits of LISS Cardio
- Burn calories and lose fat, without exhausting yourself. Exercising at a low intensity means that the primary source of energy is what is being used to fuel the body. That energy source is fat, making LISS cardio an ideal fitness plan for those who have fat loss goals. LISS cardio is also great for burning calories without putting too much physical stress on the body.
- Reduced pain and soreness. Not only is LISS cardio low intensity, but it is often low impact as well. This means that you’re putting less stress on your joints, tendons, ligaments, and muscles, making you less prone to next-day soreness. Because of this, the body recovers quickly, allowing you to get back to it the next day without overexerting yourself.
- Lowered resting heart rate. LISS cardio is performed at a steady pace, without the uptake in intensity, and without the occasional increased stress on the heart. In fact, when participating in LISS cardio, the intensity should not exceed 60 to 80 percent maximal heart rate. In order to determine your ideal heart rate for LISS cardio, subtract your age from 220. Your LISS heart rate will be between 60 and 70 percent of this number.
Drawbacks of LISS Cardio
There are a few downsides to LISS cardio. Such as pushing yourself too hard, not finding enough time in the day, and dealing with your body adapting to the intensity of the exercise.
- It is possible to overdo it when participating in LISS cardio. This is especially the case when fat loss is your main goal. Since spending exuberant amounts of time participating in LISS cardio can cause the metabolic rate to drop, fat loss is much harder to achieve. If you push your body too hard, you’ll start using up other sources of energy, and in extreme situations, muscle loss can even be expected.
- It can be very time-consuming. Unlike HIIT, LISS cardio is not something that you can do on your lunch break, or decide to do on a whim. It takes time, and usually, you have to plan and schedule it into your day. This is not ideal for those who are already squeezing every second they can get out of their day, no matter how invested in their physical fitness they may be.
- Eventually, your body adapts, and you have to push harder. This usually means training for longer periods of time in order to continue seeing physical changes. Since you’re so busy keeping up and maintaining weight loss, a boost in muscle mass or strength is unlikely.
While low-intensity steady state cardio is an excellent exercise that has a place in almost every fitness routine, high-intensity interval training proves to be the superior method when it comes to health benefits.
While HIIT uses a different method than LISS cardio in order to burn fat and lose weight, they both do an excellent job at being fat-burning exercises. Depending on your goals, this may make one form of fitness more appealing than the other. If fat-loss is your primary fitness goal, LISS is a great option. However, if your goals are weight loss and overall better physical health, HIIT might be for you.
It is easy to see that HIIT is much more time-friendly than LISS cardio, and that can be one of the deciding factors that make or break it for you. If you find that you don’t have a lot of time to spare during the day for physical fitness, the quick sessions of HIIT might seem appealing.
Overall, high-intensity interval training is superior in the amount of health benefits associated with this form of physical exercise. Not only is HIIT a great way to lose weight, but there are also many cardiovascular and metabolic benefits associated with this type of exercise. As always, figure out what your fitness goals are before deciding which method is best for you.
Article by: Marc Shulman
Divided Labs Athlete
2014 Mr Illinois Bodybuilding Champion
Nationally Accredited Trainer