When it comes to burning off body fat, there has been a debate raging for decades between the two key forms of exercise – aerobic and anaerobic. Both have their passionate advocates who swear by the effectiveness of their chosen system. But which one wins out when you remove the passion and consider the evidence and the science?
Let’s delve into the issue to find out.
Haven’t got time to read the entire article? No problem – here’s the key point …
A well rounded exercise program will include both aerobic and anaerobic components. However, when it comes to pure fat burning potential, anaerobic exercise gives you the best bang for your buck.
Aerobic exercise primarily benefits the cardiovascular system. It strengthens the heart and lungs while, at the same time, burning off excess calories. Examples of aerobic exercise are walking, cycling and skipping.
The word aerobic means ‘with oxygen’. When you perform aerobic exercise, your muscles are getting enough oxygen to produce the required energy. This type of exercise is done at a steady, moderate pace and can be sustained for a long period of time.
Aerobic exercise primarily uses slow twitch muscle fibers and is best for cardiovascular health and endurance training.
Anaerobic exercise is high intensity, short duration exercise that you cannot keep up for a long time. Weight lifting and sprinting are examples of anaerobic exercise. The word anaerobic means ‘without oxygen.’ With this type of exercise, the oxygen demands on your muscles are greater than the oxygen supply. This results in the production of lactate and the stopping of the exercise.
Anaerobic exercise is best to work your musculoskeletal system.
Which is Better for Fat Loss?
Anaerobic exercise is best for fat loss. Aerobic workouts are done at a slow to medium pace and level of intensity. That is what is needed to improve your cardiovascular health as well as to improve your cardiovascular and muscular endurance. For a long time it was believed that aerobic workouts were best for fat loss. However, even though it does use a greater percentage of stored body fat for energy as opposed to glycogen, it burns a lesser amount of total energy than does certain forms of anaerobic exercise.
Wne we are comparing aerobic to anaerobic exercise in terms of fat loss, we need to realize that not all forms of anaerobic exercise are better than traditional cardio for fat loss. For example, you will burn more calories, and therefore potentially burn off more body fat, with a 45-minute steady state cardio session than with a 45-minute weights workout. The type of anaerobic exercise that we’re talking about to maximize fat loss comes under the umbrella of high intensity interval training (HIIT).
HIIT training is anaerobic because the oxygen demand will quickly be greater than the oxygen supply preventing you from continuing. This type of exercise involves doing extremely intense 20-30 second sprint sessions interspersed with even shorter rest periods.
Why HIIT is Best for Fat Loss
One of the many benefits of HIIT workouts is that they are intensity dense and time short. In fact, the traditional form of HIIT training, known as the Tabata Protocol, takes just 4 minutes to complete! During those four minutes you will get more beneficial effects in terms of fat burning that a traditional 30 minutes steady state workout on a treadmill. For people who are pressed for time (who isn’t?) this is a very attractive element.
Greater Calorie Burn
Optimal exercise is all about the best use of your time while exercising. Because the intensity level is so much higher, you will burn a lot more calories for the same time investment when doing high intensity interval training compared to steady state aerobic exercise.
Anaerobic exercise like HIIT training primarily engages your fast twitch muscle fibers. This is the opposite to low intensity aerobic exercise, which mainly activates low twitch muscle fibers. The activation of your fast twitch muscle fibers will promote the development of strength and muscle mass increase.
Every extra ounce of muscle tissue that you add to your frame will increase your metabolism. That is because it takes five times more energy to sustain an ounce of fat than it does an ounce of fat. That faster metabolism will see you burning more calories even when you are at rest.
HIIT workouts bring on what is known as the EPOC effect. This stands for enhanced post exercise oxygen consumption. This is generally known as the after burn effect. This relates to the oxygen level that the body needs to return to a normal state once the workout is over. All you need to do is to try a HIIT workout to realize how puffed out you are after the session. It takes a long time for the body to meet the oxygen deficit which has been created. This requires energy, which, in turn, increases your metabolic rate.
As a result of the EPOC effect, you will have an elevated metabolism for as many as 24 hours after your workout. That means that you’ll still bge burning off calories from your 7 am workout when you’re lying in bed that night!
Who Should Do HIIT Training?
While anaerobic training in the form of HIIT workouts are clearly the better option when it comes to burning body fat, this type of training is not for everyone. HIIT, as you have probably already worked out, is very demanding. This intense form of exercise is not for people who have limited mobility or who carry an injury. It also requires a certain level of grit and self discipline to perform consistently at the level required to see consistent results.
If you are not suited for HIIT training, I recommend doing a combination of strength training with resistance equipment and steady state cardio to achieve your body transformation goals.
Anaerobic exercise, in the form of High Intensity Interval Training, is a superior form of exercise for fat loss than aerobic exercise. To get the most benefit from this form of training, I recommend doing 3-4 HIIT sessions per week, with 8 rounds of 20 second sprints, interspersed with 10 second rest periods.
Steve Theunissen is from New Zealand and is a qualified Personal Trainer and Nutritionist with over 30 years experience. Read more about Steve in the 'about us' page.