For those of you that don’t already know, this past May I graduated with my Master’s Degree in exercise physiology from Illinois State ( Go Redbirds!) and also completed my undergraduate degree in exercise science. My thesis topic was spent looking at how dietary intake/composition effects fuel metabolism during increasing intensity aerobic exercise. In layman’s terms I was studying how the percent of macronutrient breakdown effected what fuel (carb, fat, sometimes protein) individuals were burning during increasing intensity exercise. So after reading a sh** ton of research this is the consensus that I came to!
What is the best type of cardio for fat loss?
This is a very common question and topic that I, and I’m sure every trainer has been asked from clients and individuals that are trying to lose weight. So, what is the secret? Which type of cardio is best for someone trying to burn fat? As always, there is no clear cut answers for questions like these. Especially when it comes to weight loss. There is no black and white answer for an entire population, and a lot of gray areas but there are a variety of factors that need to be taken into consideration in order to best answer this question.
Is cardio your best option?
Typically, the goal when someone is trying to lose weight, is to lose as much weight as possible in the quickest amount of time. While this ideal, it’s not optimal for your body composition or health. Participating in any type of exercise program will result in an energy expenditure (calories burned) and weight loss will follow when the energy expended is greater than the energy consumed (total calories consumed). So, what type of exercise results in the greatest caloric burn? Again, there is a lot of research that shows cardio is best, and then there is a lot of research that shows weight training is better.
After completing a literature review on the effects of resistance training programs vs. aerobic (cardio) training programs on body composition in women. I found that more studies showed greater body composition changes, (meaning their muscle mass increased while fat mass decreased) in women that were first in a caloric deficit and that consistently participated ( anywhere from 6 weeks to 12 months) in a resistance training program 4-6 days per week that incorporated strength rep ranges of 4-6 reps, hypertrophy rep ranges of 8-12 reps, and endurance rep ranges of 15-20 reps. Compared to women that JUST did cardio 4-5 days per week. Not to say that cardio isn’t an option as tool for weight loss. These findings merely suggest that greater body composition changes are seen when a resistance training program is implemented using a variety of rep ranges. Cardio can also be used as a tool to increase an individuals energy expenditure.
…….But Taylor you’ve typed a whole entire paragraph and you STILL haven’t answered my question! Here it is….. are you ready?
What is the best type of cardio for fat loss you asked?
IT DEPENDS ….and were back to that gray area again
HIIT (High Intensity Interval Training)
When the goal is to try, and maintain as much muscle as possible research shows that HIIT is best. HIIT training includes short burst of high intensity exercise that increases your heart rate (80-90% of heart rate max) and is followed by a short period of rest and then is repeated for however many intervals. Although, during high intensity activity the body burns mainly carbohydrate as fuel, the overall caloric burn ends up being greater than if you did a low intensity workout. Meaning, if the two were performed for an equal amount of time you end up burning more calories during a HIIT workout because your intensity level is much higher. Then, there is also EPOC (Exercise Post Oxygen Consumption) that plays a role in caloric expenditure, also known as the after burn. Not going to go into much detail because this is a topic for another article in itself. During any type of high intensity exercise, there is a greater EPOC compared to low intensity exercise thus resulting in a greater caloric burn.
On this graph, GREEN represents fat and BLUE represents carbohydrate. As you can see as exercise intensity increases grams of carbohydrate burned increase and grams of fat decrease. Vise versa. Grams of fat burned increases when intensity is lower and grams of carbohydrate decrease. (Exercise Physiology
Steady State or LISS (Low Intensity Steady State)
During low intensity steady state exercise and during rest, the body mainly uses fat as fuel source. Yay I answered your question! But keep reading…….
Steady state exercise includes activities such as endurance running, biking, swimming, walking, hiking, rowing…etc. Usually heart rate is anywhere between (40%-60%) of HR max). This type of cardio is great for individuals that already have endurance built up and enjoy participating in endurance activities. It is also a low impact activity so its great for all ages. As I stated in the HIIT section, in order to burn as much calories you do during high intensity activities, you would need to do LISS activities for a longer period of time to equate to the same overall calorie burn.
So what is the overall consensus?
As always it depends on the goals of the individuals and their personal preference. Incorporating resistance training rather than just cardio alone for fat loss will result in greater body composition changes. But including cardio is a great tool for weight loss and increasing caloric burn especially if the scale isn’t moving down much. HIIT cardio is more beneficial you are looking for the best “bang for your buck”, the workout is shorter and results in greater energy expenditure. But steady state is great in that the main fuel burned is fat. This type of cardio just needs to be performed for a longer amount of time to create a higher energy expenditure. Including both into your training program can be beneficial for your fat loss goals!
I am very passionate about what I do! If you would like to work together you can check out my Online Coaching page and fill out a form and I will be in contact with you ASAP!
Stay fit!
Sources:
Romijn JA, Coyle EF, Sidossis LS, et al. Regulation of endogenous fat and carbohydrate metabolism in relation to exercise intensity and duration. Am J Physiol. 1993;265(3 Pt 1):E380-391.
Coyle EF. Substrate utilization during exercise in active people. Am J Clin Nutr. 1995;61(4 Suppl):968S-979S.
Jeukendrup AE. High-carbohydrate versus high-fat diets in endurance sports. In. Vol 51: Schweizerische Zeitschrift fur; 2003:17-23.
Mcardle, W. D. (2014). Exercise physiology: nutrition energy and human performance. Lippincott Williams And W.
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