It’s common to wonder whether your workout is really helping you get results. That’s because misinformation abounds about how to best do a cardio workout for fat loss, and that bad information leads to wasted time and poor results.
What kind of cardio can you do to promote massive fat burning?
There is a better approach, which I want to share with you. To illustrate my point, I will use a few of my workouts and give you the actual calories and fat calories burned during those workouts.
Let me start by explaining what I did. I took three different kinds of workouts and compared the results. The comparison was made between high intensity interval training (HIIT), long slow distance training (LSD), and medium distance interval training. I chose these three methods, because the first two, HIIT and LSD have been at the center of a debate over the last few years, and there is a great deal of controversy as to which is better for weight loss.
I also added middle distance interval training, so that we could see how this method to compared to the other two. I recorded each session and wrote down the duration of the workout, my heart rate, how many calories I burned, and the total fat calories burned. I used my Polar FT60 heart rate monitor for this comparison test.
This experiment is not exact, but it gives us a good baseline to compare the three workouts. So, don’t worry about the exact numbers used here. Your caloric burn will different than mine, your heart rate will be different than mine, and your fitness will be different the mine. The conclusions that we draw are more important than the actual numbers used.
First, so we are all on the same page, let’s take a look at what I mean when I say LSD, HIIT, and MDI.
Is HIIT The Best?
High Intensity Interval Training is akin to sprint training. Essentially, you run very “hard” and then you rest and repeat the effort. The important thing to remember when doing HIIT is that “hard” means at or close to your maximum effort. That’s why I say it’s like sprint training, you have to really bust your behind and work to your greatest potential. On level of 1-10 in terms of effort, HIIT is an 8-10, when done correctly.
One commonly used method of HIIT training is to work hard for 1 minute and then recover for 1 minute, and then continue this pattern for the duration of the workout. For fat burning purposes, it is best to slow to a jog during your recovery period rather than stopping entirely. You will burn more calories this way.
You can do HIIT training on a variety of exercise equipment, if you don’t want to run. I like bikes and elliptical machine for this kind of workout. It’s not important what piece of equipment you chose, it’s only important that you reach a level of effort of 8-10.
- Increases resting metabolic rate
- Improves aerobic fitness
- Burns calories post exercise
- Great for sprint sports
- Won’t lead to muscle loss
One thing that many people don’t realize is that an intense workout causes the body to burn calories after the workout, which is often referred to as the afterburn effect. Exercise is a process of breaking down the body and rebuilding it, but stronger. During the rebuilding process, the body needs energy to do the repairs, that energy comes from calories.
Since HIIT is an intense exercise protocol, you will get the benefit of the afterburn effect and burn some extra calories long after your workout is complete.
The Bad About HIIT
- HIIT is hard
- It requires recovery and cannot be done everyday
- It’s easy to over train
- There is a limit to how much HIIT you can do in a workout
Because of the intense nature of HIIT, your body will need time to recover afterwards. It is not practical to do HIIT everyday, and it’s difficult, even for very fit people, to do HIIT for a long duration. So, to burn more calories, you cannot simply do more HIIT without running the risk of overtraining. In short, you have limits to how many calories you can burn per week from doing HIIT.
Some very misinformed people will try to convince you that doing more HIIT is the answer to weight loss stalls, but they are sorely mistaken. Their recommendation will lead to overtraining, and overtraining is counterproductive to fat loss.
How Did HIIT Score?
My HIIT workout followed this pattern: 1 minute of a hard run followed by 1 minute of an easy recovery jog. I did this for a total of 23 minutes.
Time: 23 minutes, no measured warm up
Heart rate average: 158
Heart rate max: 168
Calories burned: 315
Fat calories: 31
Is LSD the best?
Now, just to be clear, when I talk about LSD for fat loss, it has nothing to do with Timothy Leary and acid trips. So, don’t interpret this as a suggestion you find the local drug dealer and start doing drugs to lose weight. Rather, I am referring to Long Slow Distance training (LSD).
LSD training is the most common approach to cardio training. It’s often referred to as steady state training, because you exercise at the same pace for your entire workout.
LSD training is not very intense. The goal of LSD training is to exercise for long periods of time, and to do this we need to find a more comfortable, slower pace to train at, or we won’t last. It is best to do LSD training at an intensity level somewhere around the 4-7 range.
The Good About LSD
- Great for building aerobic fitness (cardio output)
- Most anyone can do it
- Greater percentage of fat is used for fuel
I know a lot of you read that last bullet point about fat being used for fuel during LSD training and immediately thought that means LSD rocks for burning fat. There’s good news and bad news with this, which I’ll dive into later, but first, let’s look at some of the negatives around LSD training.
The Bad About LSD
- LSD running can cause repetitive stress injuries
- It’s time consuming
- It can get boring
- Less calories burned post-exercise
- Can lead to muscle loss
Because LSD is not a high intensity exercise, there is less post workout repair needed, so the afterburn effect is pretty small. Because of this, the main benefit to LSD is the calories burned while doing the exercise.
How did LSD stack up?
Since this was an LSD workout, there was relatively small variation in pace and heart rate throughout the entire workout.
Time: 46 minutes, no measured warm up
Heart rate average: 122
Heart rate max: 131
Calories burned: 396
Fat calories: 99
Is MDI the best fat burning cardio exercise?
Middle Distance Intervals (MDI) are not very popular with the fitness crowd. You are more likely to see track athletes and middle distance runners do these types of workouts. They are similar to HIIT in that there are structured so that there are work periods and rest periods. But, MDI is different in that the work periods and rest periods are much longer. For example, a workout might consist of 5 minutes of work with a 2 minute recovery jog.
When doing MDI, the important thing to remember is to try to maximize the effort during the work period. I do this by measuring the heart rate, but it can be done be estimating your work effort like we talked about with HIIT. An effort of 7-9 is the right range for MDI.
Benefits of MDI
- Great for aerobic adaptions
- Helps increase race speed for middle distance runners
- Good for many field sports, like soccer
- It’s fun
Downside to MDI
- It can be very challenging
- Takes some time to find the right pace or intensity level
- High intensity and requires recovery
How did middle distance intervals stack up?
I wanted to make sure the duration of the workout was exactly the same as the HIIT test, so this workout was done for exactly 23 minutes. That was a bit of an uneven number, so I did 4 sets of 4 minute intervals with a recovery jog of 1 minute between each set. I ended the session with a 3 minute interval, so that I finished exactly at the 23 minute mark.
Time: 23 minutes, no measured warm up
Heart rate average: 160
Heart rate max: 167
Calories burned: 321
Fat calories: 32
So what does this mean and how do we know which one is best for burning fat?
First, let me point out that each workout burned a lot of calories. However, the LSD workout was twice as long as the HIIT and MDI workouts, and that the results were not twice as good. In short, LSD is not an efficient workout.
There wasn’t a whole lot of difference between HIIT and MDI. For athletic training purposes there are differences, but for fat loss, there aren’t.
Also, since I cannot measure the calories burned due to the afterburn effect, it is reasonable to assume that both HIIT and MDI workouts actually burned a few more calories than I could measure.
LSD burned a higher percentage of fat. It burned 25% vs. the 10% burned by MDI and HIIT. Despite this, you have to devote more time to an LSD workout to see an equivalent benefit. So, the question becomes is all that extra time worth burning a few more fat calories? In my mind, it’s a rather small gain for all the extra time you have to spend to get the benefit.
Which brings us to the big conclusion: HIIT and MDI are more efficient and give us a great way to burn calories. But, they are too demanding to do everyday. LSD can be done everyday, but you better clear you schedule because you will need more time. Unfortunately for many people long workouts 6 days a week are not an option.
Putting together a solid cardio fat loss plan:
I think many people could accelerate their fat burning by utilizing both HIIT and LSD in their training. Make HIIT training the foundation to your program and add in LSD sessions that will burn extra calories, but also allow you to recover from your hard HIIT days. This will keep us from overtraining, while allowing us to create a program that maximizes our fat burning potential.
Put the cardio plan to work for you:
Monday: MDI or HIIT
Wednesday: MDI or HIIT
Friday: MDI or HIIT
The benefit to this plan is it’s a really good use of our time. MDI and HIIT are short workouts and can be done in 20-25 minutes. Since the LSD workouts in this plan are recovery workouts, our goal is to go easy on these days, so that we are ready for the HIIT session on the following day.
LSD workouts are generally around 45 minutes, but if you are pressed for time it’s OK to do 30 minutes. Also, if you’d prefer to go for a walk instead of a leisurely jog, that’s fine, too. You will still burn up a lot of calories, if you keep at it long enough.
Now that you know how to do cardio training to burn the most amount of fat possible, you are ready to become a fat burning furnace. Just pick an exercise you like, and go out there and do it.
For your reference, here is more info on HIIT and it’s effect on metabolism.