Tyler Robbins Fitness

B.Sc. Biochemistry, Certified Strength and Conditioning Specialist (CSCS), Certified CrossFit Trainer (CCFT/CF-L3), USA Weightlifting Level 1

Filtering by Tag: Exercise

Does exercise actually burn fat?

How absurd is this?

How absurd is this?

So, does exercise really actually burn or melt body fat? Well, a very plain and simple answer would be no, not really. The answer is certainly more complicated than that, and I plan on explaining myself further, but this is certainly a topic that most people get wrong, or are greatly misinformed.

Sure, a lot of you may read this blog and think, "Your argument is just semantics. Exercise (in a roundabout way) burns fat!" Well, maybe. Maybe this could be considered semantics, but I personally believe this plays a crucial role in how people perceive not only the role of exercise, but the role of food and their diet as well!

Heavy science jargon and content ahead. I have done my absolute best to explain what is going on here. You've been warned. If you're still here, let's dive in.

I came across this interesting review the other day:

Abdominal fat reducing outcome of exercise training: fat burning or hydrocarbon source redistribution?


Fat burning, defined by fatty acid oxidation into carbon dioxide, is the most described hypothesis to explain the actual abdominal fat reducing outcome of exercise training. This hypothesis is strengthened by evidence of increased whole-body lipolysis during exercise. As a result, aerobic training is widely recommended for obesity management. This intuition raises several paradoxes: first, both aerobic and resistance exercise training do not actually elevate 24 h fat oxidation, according to data from chamber-based indirect calorimetry. Second, anaerobic high-intensity intermittent training produces greater abdominal fat reduction than continuous aerobic training at similar amounts of energy expenditure. Third, significant body fat reduction in athletes occurs when oxygen supply decreases to inhibit fat burning during altitude-induced hypoxia exposure at the same training volume. Lack of oxygen increases post-meal blood distribution to human skeletal muscle, suggesting that shifting the postprandial hydrocarbons towards skeletal muscle away from adipose tissue might be more important than fat burning in decreasing abdominal fat. Creating a negative energy balance in fat cells due to competition of skeletal muscle for circulating hydrocarbon sources may be a better model to explain the abdominal fat reducing outcome of exercise than the fat-burning model.

Lots of science talk, let's break things down and give some thoughts as to what is being discussed here.

Fat burning, defined by fatty acid oxidation into carbon dioxide, is the most described hypothesis to explain the actual abdominal fat reducing outcome of exercise training.

This is one of these popular "facts" making its way around the internet lately. The idea that as you exercise and burn fat, the fat then just starts melting and you magically breathe it out as carbon dioxide. Sure, carbon dioxide is a by product of metabolism and respiration, and you certainly burn some fat during exercise, but it isn't really that simple.

This hypothesis is strengthened by evidence of increased whole-body lipolysis during exercise. As a result, aerobic training is widely recommended for obesity management.

Right. This has been heard for years. This is actually one point that seems to be at least somewhat well-known to be a mistruth now. That just because adipose tissue (body fat) is only burned in the presence of oxygen (oxidation), then low-level exercise must be best for burning fat. Right? Go for a nice long, easy run on the treadmill and you will get thin and sexy. Well, not exactly. My readers should know that intense exercise is better suited for reducing body fat by now so lets move on.

anaerobic high-intensity intermittent training produces greater abdominal fat reduction than continuous aerobic training at similar amounts of energy expenditure.

Study after study after study has shown just this - high intensity interval training is more effective for reducing body fat than steady state cardiovascular exercise.

significant body fat reduction in athletes occurs when oxygen supply decreases to inhibit fat burning during altitude-induced hypoxia exposure at the same training volume

Ah good, now things get interesting. So what this states is that body fat is reduced more in individuals that have decreased oxygen supply. Doesn't oxygen need to be present to burn body fat? Well, as the previous statement pointed out to us, high intensity exercise - you know, the type that has you gasping for air (oxygen deprived), is actually best at obtaining or maintaining an optimal body fat percentage.

Lack of oxygen increases post-meal blood distribution to human skeletal muscle, suggesting that shifting the postprandial hydrocarbons towards skeletal muscle away from adipose tissue might be more important than fat burning in decreasing abdominal fat.

This gets into the meat of this paper's argument, and one that I will elaborate on below. People need to stop thinking of exercise as a fat burner, and instead consider exercise (both resistance training and "cardio") as a means to make your body a better fat-burning machine.

Creating a negative energy balance in fat cells due to competition of skeletal muscle for circulating hydrocarbon sources may be a better model to explain the abdominal fat reducing outcome of exercise than the fat-burning model.

Once I dove deeper into this paper, I got a better sense of what point the authors were trying to prove. Your muscle cells and fat cells both have the ability and goal in mind to store energy. In fact, there seems to be a competition between the two. Your body is constantly varying its sources of energy based on your level of activity. When you are exercising intensely, your body is primarily using glucose as a fuel source, for example. Sure, there is some fat being oxidized, but the primary fuel source is glucose.

Compare that to the amount of fat being burned between aerobic exercise, resistance exercise, and non-exercise. Sorry resistance trainee camp, not even you can argue that resistance training is "better" than aerobic exercise for burning fat - at least not directly.

This one is telling for the "exercise until you puke" camp. The notion that the harder you exercise, the more fat you burn is total b.s. as well. Do I think intense exercise is important? Absolutely. Do I think intense exercise is necessary for weight loss and body fat reduction? Not really, or at least not primarily. Some is good, but only to a certain level.

So what is the point to all of this? Well this is where the semantics comes in.

The current understanding is that when you are exercising, your body is literally burning away those love handles as you crank through all those burpees or squats. As we saw in figure A above, this is simply not the case. Yes, intense exercise promotes lower body fat percentages, but not because the fat is literally being burned and exhaled as carbon dioxide. Ok, then it must be the post-workout "burn" where metabolism is revved up. That is a common theme, correct? Again, not the case. Because oxygen must be present in order to burn fatty acids as a fuel source, by exercising intensely, you are specifically forcing your body to turn to glucose as a primary energy source.

So low-level exercise is better for burning fat, right?

Well, no. Research has proven time and time again that shorter, intense exercise is not only more efficient and effective than low-level, steady-state exercise to improve cardiovascular health and a healthy body-fat percentage.

So what gives?

As this review points out, the mindset as to what exercise actually does to your body and how body fat is reduced is the most important part. Exercise, and more specifically, intense exercise (ideally with external resistance, i.e. weights) not only builds strong muscles, but it turns your muscles into energy consuming machines. This causes a domino effect.

  1. Body fat (adipose tissue) and lean tissue (muscle) are constantly competing over consuming incoming calories. The body seems to give preferential treatment to muscles the harder they work.
  2. Energy that is not consumed and stored in muscles goes to body fat.
  3. Carbohydrates are broken down into glucose. When your body is not active, glucose is not being burned as readily by muscles, so there is more glucose present and glucose becomes the primary energy source even during low-level activity (most of the day).
  4. Fatty acids from adipose tissue are the primary energy source for majority of your day (i.e. the time you aren't working out intensely). But if glucose is present, blood sugar (glucose) becomes the energy source of choice.
  5. If your body is using blood glucose as an energy source, body fat deposits are not reducing.
  6. If your muscles are consuming large amounts of energy, especially carbohydrates, then your body primarily uses fatty acids (adipose tissue) as the energy source.


So although this isn't necessarily different than what most people should already know - intense exercise makes you thin and keeps you healthy, the mindset for how this works should change. Resistance training is used to not only strengthen the connective tissues of the body, but to make your muscles greater calorie-burning machines.

Carbohydrates should be consumed almost entirely just prior to, and/or immediately following a workout in order to reduce the amount that is stored as body fat.

Although intense activity is great and very important for overall health, the more active you are the rest of the day during "low-level activity" (walking, working, playing, etc.), the more effective your body will be at reducing your body fat percentage.

Diet vs. Exercise for Weight Loss

A simple search of my blog will show you how many times I have written about this topic, but a new study published last month gives us even more insight - and confirmation, into what I have been writing about in the past.

A systematic review and meta-analysis on the effects of exercise training versus hypocaloric diet: distinct effects on body weight and visceral adipose tissue.Abstract

Exercise training ('exercise') and hypocaloric diet ('diet') are frequently prescribed for weight loss in obesity. Whilst body weight changes are commonly used to evaluate lifestyle interventions, visceral adiposity (VAT) is a more relevant and stronger predictor for morbidity and mortality. A meta-analysis was performed to assess the effects of exercise or diet on VAT (quantified by radiographic imaging). Relevant databases were searched through May 2014. One hundred seventeen studies (n = 4,815) were included. We found that both exercise and diet cause VAT loss (P < 0.0001). When comparing diet versus training, diet caused a larger weight loss (P = 0.04). In contrast, a trend was observed towards a larger VAT decrease in exercise (P = 0.08). Changes in weight and VAT showed a strong correlation after diet (R2  = 0.737, P < 0.001), and a modest correlation after exercise (R2  = 0.451, P < 0.001). In the absence of weight loss, exercise is related to 6.1% decrease in VAT, whilst diet showed virtually no change (1.1%). In conclusion, both exercise and diet reduce VAT. Despite a larger effect of diet on total body weight loss, exercise tends to have superior effects in reducing VAT. Finally, total body weight loss does not necessarily reflect changes in VAT and may represent a poor marker when evaluating benefits of lifestyle-interventions.

To summarize:

Calorie restriction (hypocaloric diet) is effective for weight loss. Exercise is effective for weight loss, although not as good as a hypocaloric diet. Hypocaloric diet and exercise in combination is effective for weight loss. Exercise is best at reducing visceral fat (adipose tissue packed in and around our organs).

So what is better for overall health?

Well, both calorie restriction and exercise are effective for improving your health in various ways, and the political answer would be that they are both effective in maintaining overall health, however what most people don't realize is that both have their strengths and weaknesses, pros and cons depending on your goals. Let me explain further.


  • For the most part, eat more than you burn to gain weight and eat less than you burn to lose weight.
  • Sure, it is possible that genetics can play a role in your metabolism and how you manage various macros (carbs, for example), but if you are gaining weight, then you are eating too much.
  • On the flip side, if you are losing weight, you are not eating enough.
  • Weight loss includes muscle loss, so by restricting calories and not resistance training you are potentially setting yourself up for strength and connective tissue loss.
  • As the above study tells us, dieting to lose weight is not as effective at removing visceral fat as exercise is. I have written about this before - "Skinny Fat" is Dangerous.
  • Losing weight too quickly (extreme calorie restriction) can cause a rebound effect known as the "Set Point Theory."
  • Protein consumption is extremely useful to maintain a healthy body weight. Make sure to increase your overall consumption as you age.


  • Most people vastly over-estimate the number of calories exercise burns. This is especially true for individuals who just "show up" to the gym and don't exercise hard enough.
  • Yes, exercise can be helpful in healthy weight management, but it is not some magical formula that can prevent obesity if you do not diet appropriately.
  • Exercise is extremely beneficial for your brain, mood, bones, connective tissues, muscles, etc. Honestly, the list is so extensive, in my opinion, nobody should go without exercise, or more specifically, a well-rounded program consisting of cardiovascular exercise and resistance training.
  • As the study above tells us, exercise is more effective then dieting alone when it comes to reducing visceral fat - fat that can raise the risk of other diseases.
  • When it comes to changing the way you look, exercise is best at it can help increase lean mass (muscle), improve the appearance of your skin/hair, improve circulation, etc.

Hitting a wall?

Hey TRF fans and readers, I’m back! I apologize for the nearly 7-month hiatus with my blog, but life has been busy. One of my New Year’s Resolutions, however, has been to re-kindle my interest for writing. It certainly helps when there are so many interesting studies coming out in the world of exercise physiology and nutritional sciences lately. So, over the next several weeks/months, I should hopefully be more consistent with my writing.

This blog is especially relevant to many of you readers, or perhaps for someone you know who has used the start of the new year as a reason to get back to exercising.

Have you, or someone you know, started an exercise regimen lately? Has the immediate results seemed to have slowed after a few weeks in? Well it turns out, according to a study recently published in Current Biology, that our bodies are great at adapting to stimuli that we place on it. This may either be a blessing or a curse.

Warning, incoming science jargon:

“After adjusting for body size and composition, total energy expenditure was positively correlated with physical activity, but the relationship was markedly stronger over the lower range of physical activity. For subjects in the upper range of physical activity, total energy expenditure plateaued, supporting a Constrained total energy expenditure model. Body fat percentage and activity intensity appear to modulate the metabolic response to physical activity. Models of energy balance employed in public health [ 1–3 ] should be revised to better reflect the constrained nature of total energy expenditure and the complex effects of physical activity on metabolic physiology.”

What does this mean? Well, just as our bodies adapt to stimulus like resistance training by building stronger muscles and connective tissues, we also seem to adapt to intense exercise by getting better and better at managing energy.

So, if you are not necessarily witnessing the “results” you were hoping for with exercise alone (losing weight, decreasing body fat), then increasing the amount of exercise you do, or the intensity of exercise you do may not be the answer. What this study is telling us, is that just because your work ethic has been multiplied, doesn’t mean your energy output (i.e. calories burned) has been multiplied by the same amount. Maybe the "calories in vs. calories out" isn't as accurate as we once thought.

Don’t take this an excuse to either a), cancel your gym membership, or b), work less hard in the gym, because that is not the intention of this blog at all. In fact, I am always advocating routine and intense exercise for optimal health. What I am, saying, however, is that if you are not getting the results you are looking for when it comes to weight loss or body composition, then pushing your body harder and harder isn’t necessarily the answer.

"Double Impact" - 30 minute Legs and Back Workout



I always thought Sumo Squats were wide leg squats but you do them with legs shoulder width. Any particular reason?

This was intended to really stress the point of wider knees during the squat. I called them Sumo Squats, but really they could've (and should've) been called goblet squats. I was trying to stress a more natural squat form similar to a front squat, for example, using a barbell.

I think you referred to bent over rows as "reverse pushups" in the video. I had always understood reverse pushups to be a bodyweight exercise where you use a dipping bar or a bar bell on a rack, hang face up from it, and pull yourself up to the bar. You can vary the angle of your body by moving the bar up and down or by bending your knees more or less to vary the intensity.

Yup, the pull action you are referring to is actually very similar to the barbell row. The reason I refer to it as a "reverse push-up" is because of the plane the arms travel through their range of motion. I used dumbbells in this workout, although it is intended to be done with a barbell. I actually prefer this variety versus the one you refer to by pulling your body weight towards a bar because the standing variety recruits far more muscle in the glutes, hamstrings, and lower back (not to mention the mid and upper back!)

Exercise - are you getting enough?

I read an interesting article over at CBC (Canadian Broadcasting Corporation) the other day. Although this was a Canadian study, I have a feeling the results apply to most of North America and possibly most of Western Society.

About 15 per cent of adults and fewer than 10 per cent of teens meet physical activity guidelines for health benefits, with some not really realizing what it takes to make gains, according to Statistics Canada.

Those are some scary numbers! I knew that there was a health crisis facing majority of the population, but to be honest, I didn't realize that it was this bad.

Canadian physical activity guidelines, published in 2011, recommend those aged 12 to 17 get 60 minutes of moderate to vigorous intensity physical activity daily. For adults, the guidelines recommend that adults obtain 150 minutes of
physical activity of that intensity per week, accumulated in bouts of 10 or more minutes.

So, 150 minutes of vigorous activity every week. Break that down and that works out to be 30 minutes of good, solid exercise, 5 days a week (P90X3 or Focus T25 anyone?). So how hard is vigorous exercise exactly? Well:

The guidelines say that for adults to achieve a moderate intensity, their heart rates should be within the range of 64 to 76 per cent of their maximum heart rate and between 77 to 83 per cent for vigorous intensity.

So how do I figure that out? Well, a really quick and easy way of calculating your heart rate goes like this (this is a basic method but should work for most of the population):

220 - your age = Theoretical Heart Rate Maximum (HRM)
%Heart Rate (HR) x HRM = Range Guideline

So, I will use myself as an example:

220 - 29 = 191 (HRM)
0.64 x 191 = 122 beats per minute (bpm)
0.76 x 191 = 145 bpm

0.77 x 191 = 147 bpm
0.83 x 191 = 159 bpm

So, for my, moderate exercise is when my heart rate falls between 122 - 145 beats per minute, and vigorous exercise is when my heart rate falls between 147 - 159 beats per minute. You can get heart rate monitors for relatively cheap these days, but if you don't wish to buy one, then try a couple of these tips:

  1. Stop and check your own pulse for 15 seconds during or immediately following exercise. It only takes 15 seconds so don't worry about losing momentum during your workout or anything like that. Multiply the number of beats you count by 4 to get your beats per minute.
  2. A less accurate, but still relatively useful tool is the talking test. If you can carry on a conversation with someone, you are more than likely doing "light" exercise. If you can talk, but only between breaths, then you are more than likely in the "moderate" range. And if you are breathing too heavy to speak or can only mutter a few words here and there, then you are in the "vigorous" zone.

That's it! I know, a lot of the readers of my blog are probably already hitting these goals...you are, aren't you? That is why these numbers are so scary. According to this study, only 15% of adults and 10% of teens are getting enough vigorous exercise. And according to the study, there seems to be a measurable percentage of the population who thinks they're getting enough, but simply aren't! Not only that, but make sure you are always pushing yourself,

Brown raised another potential issue. Sometimes she sees people working out at the gym doing the same exercise on the same machine at the same level each time without taking into account that they're getting fitter and need to increase the intensity to get fitter.

Remember, the more you exercise, the more your body will improve. As you improve, your cardiovascular system becomes more efficient and can complete the same level of work as before with less effort or strain. This means that even if you went for a light 1 mile jog the other day and were breathing heavy, that doesn't mean you will always will. Instead, try increasing your distance a bit or increasing your pace.

Staying motivated doesn't work...


Yes, I understand that I am a person why tries to motivate others every day. I post motivational quotes every day, I post pictures of my workouts nearly every day, and I even run a Facebook Challenge Group whose intention is to keep like-minded folks plugged in together to stay motivated and accountable.

Those are all tools, however. Tools to help individuals make the first, second, or even third step to change their lives. Another tool I use to help others get motivated involves figuring out a "why." Maybe you hit that point where you see yourself in the mirror and don't like what you see. Maybe you have kids, a family member, or a significant other that you wish to be around and spend lots of time with.

All of those tools are great for motivation and help you get going. What I am writing about today goes well beyond that. You must program healthy living into your brain so that you don't even need some catchy internet meme to get you going to do your workout anymore, you just know what you have to do.

There are things in your life right now that require a serious time commitment or devotion from you. Simple things like brushing your teeth, walking the dog, preparing meals, etc. You know, the "mundane stuff" in life. Go beyond that with school, work, family time, social commitments, home maintenance, etc. Those things often require a lot more of your time and energy, but you just do them because they are part of your life.

Exercise and healthy eating (I hate the word diet or dieting) need to be a part of that "automatic" part of your day.

I think far too many people leave it up to chance or feeling. The sun is out, I am feeling good, I think I will head to the gym or go for a run. I personally don't think that way. When I wake up in the morning, I almost immediately go through my list of to-do's for the day, which includes my workout for that day. I figure out my schedule based on what my wife is doing, what my boys' schedules are like, and figure out when I am going to do my workout, not if.

Here's another analogy. Use health and fitness as a tool so that you can do things better. You go to school to learn and improve yourself. You have a job or career so that you can earn money to purchase things like food, shelter, and entertainment. You should use healthy foods and exercise as your tool to feel better and function better.

Take Tony Horton for example. Now 56 years old, even with his busy schedule traveling around promoting health and fitness (as well as his products), he still manages to get his workouts done. Why? Because it is ingrained in his everyday life. I certainly hope I am well enough to be like him when I am 56 years old.