The age old debate of ‘is cardio needed for fat loss’ is not only one of the most long standing but also one of the most hot button topics in the fitness world.
On one side of the spectrum there are those who believe that cardio is a complete waste of time and energy, and on the other side of the debate there are those people that believe hours of cardio is needed daily for fat loss.
In this article we are going to get to the bottom of cardiovascular exercise, and determine if you should be doing cardio or not in order to achieve your fat loss goals.
Benefits of Cardiovascular Training
First, we would like to put to rest the myth that cardiovascular training has no health benefits. Cardio exercise in fact provides a variety of health benefits including:
- Increased metabolism during and shortly after exercise.
- Increased VO2 max, oxygen efficiency/ utilization throughout body.
- Increased HDL cholesterol (the good cholesterol).
- Improved mood via release of endorphins.
- Improved insulin sensitivity (prevents insulin resistance and type 2 diabetes).
Negative Consequences of Cardio
However, nothing, including cardio, is without risk and or negative aspects. Some possibly harmful effects of cardio can include:
- Injuries to muscles and or joints due to repetitive movements.
- Increased appetite (which can cause people to eat more calories than they burn off).
- Muscle loss.
- Kidney problems (Rhabdomyolysis), usually only when exercising at an extremely high level of intensity.
Is All Cardio Created Equal?
Another thing to note when talking about cardio is that there is a large spectrum of activities that constitute as “cardio exercises”. First let’s break down cardio exercises into two parts:
Intensity is subjective to the person doing the exercise, and it is most easily measured by using a rate of perceived exertion (RPE) scale or heart rate. For example a marathoner may find going for a 3 mile run at a fast pace extremely easy, but a potentially out of shape office worker may find that a 3 mile run is nearly life threatening.
The three classic examples of differing intensities within the cardio realm are:
- Low intensity such as going for a stroll around the neighborhood (1-3 on RPE scale).
- Moderate intensity such as going for a jog (4-7 on RPE scale).
- High intensity such as sprinting drills (8-10 on RPE scale).
Something that is not subjective is duration, or the amount of time spent doing a certain exercise. Duration of cardio exercise can last anywhere from seconds to hours depending on the type of exercise being done and at what intensity the exercise is being conducted.
So, Will Cardio Help Me Lose Weight?
Now that you know the basic background of cardio, you are probably still wondering if you should be spending more or less time on the elliptical or treadmill. The answer is yes, cardio can help you lose fat, but, it depends on the intensity and duration of your cardio workouts.
The most effective types of cardio workouts to lose fat are high intensity interval training cardio (HIIT) workouts. HIIT workouts can be done with any type of exercise including running, cycling, swimming, rowing, jump roping etc. HIIT workouts usually are no more than 20 minutes of exercise, done at a high intensity for short bursts of time, mixed in with moderate intensity for rest. See table below for an example:
HIIT Burns Crazy Amounts of Calories
The beauty of HIIT workouts is that they burn a ton of calories, in a shorter period of time compared to moderate intensity exercise, due to the high level of intensity. Not only do you burn more calories while you are working out but you burn a considerable more amount of calories after you are done working out due to the excess post-exercise oxygen consumption or ‘after burn’ which occurs after a highly strenuous workout.
Confusing Your Body
An all too familiar phenomenon occurs to most people when losing fat. Most people embark on a moderate intensity cardio regime and for the first few weeks they start losing weight and seeing a difference in the way they look and they feel great. However, sooner or later they begin to plateau and suddenly the 2 pounds they have been losing week in and week out screeches to a halt. So, in order to see more weight loss they increase the amount of cardio they do, so instead of 30 minutes they start doing 45 minutes and then 60 minutes and then 75 minutes and so on.
The problem is that our bodies are much smarter then you think, we are genetically programmed to store fat, that is how we as a species have evolved and survived through thousands of generations. Even nowadays with abundant amounts of food, our bodies have not caught up, and are still trained to hold on to fat.
What our bodies do is become more efficient at the type of exercise you are doing. So that 30 minute bout on the elliptical may have once burned you 300 calories, but if you do that same exercise to the point that it is no longer a challenge, your body is going to spend less energy (calories) doing that same workout and you will no longer be burning 300 calories in 30 minutes.
The beauty of HIIT workouts is that you are competing with yourself, and your body determines what high intensity is, therefor as you become fitter, you can keep increasing the difficulty of your workouts, to keep your body guessing and still burning calories at a high rate.
Increasing Adiponectin Levels
High intensity interval training has also been found to increase adiponectin levels. Adiponectin is a type of protein that has many functions within the body, such as regulating glucose levels as well as fatty acid breakdown.
High adiponectin levels have been linked with a lower body fat percentage and increase in insulin sensitivity (which protects agains type 2 diabetes). Obese people have been found to have lower amounts of adiponectin than people who are of a healthy weight. Adiponectin can also act as an anti-inflammatory, which is great for protecting against preventable diseases such as heart disease, cancer, and type 2 diabetes.
Mr and Mrs Nutritionist’s Final Thoughts
We are strong supporters of HIIT workouts, and their effectiveness at helping people drop the pounds and increase their fitness and health.
However, we in no way want to discourage people from being physically active or quitting their non HIIT aerobic activities that they enjoy doing. We just want to inform you on a more effective way of dropping the pounds. But at the end of the day staying active and being healthy and doing activities that bring you joy is key.
Let us know if you have had any experience or questions regarding HIIT and weight loss.
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Kordi, M., Choopani, S., Hemmatinafar, M. and Choopani, Z. (2013). The effects of the six week high intensity interval training (HIIT) on resting plasma levels of adiponectin and fat loss in sedentary young women. Journal of Jahrom University of Medical Sciences, 11(1).
Mayoclinic.org. (2016). Getting past a weight-loss plateau – Mayo Clinic. [online] Available at: http://www.mayoclinic.org/healthy-lifestyle/weight-loss/in-depth/weight-loss-plateau/art-20044615?pg=2 [Accessed 30 Apr. 2016].