To Health Advocates—
Do we want to lose fat? Or do we want to burn fat? Is it the same? Or has successful marketing clouded our understanding?
Fat, on our body, is a stored form of energy. It is a reserve of energy in case there came a time when food was not plentiful. Scarcity was a reality of human evolution, but much less so in today’s world.
In order to create understanding around one of the most popular topics in exercise science, I think it’s important to define what is actually being said.
Below, you will see the topic of fat burning defined, with examples provided.
Additionally, you will see what the implications of fat burning are for weight loss. It’s first important to understand that fat burning and weight loss are independent of each other. They also can happen simultaneously. Understand one, and it will lead us to the other.
I hope you enjoy!
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5 Key Points from Today
Fat loss does not mean weight loss.
Weight loss means the number on the scale decreases.
Fat loss, means we lost fat off our body. We can maintain our number on the scale, but still lose fat off our body. This would be an improvement in body composition. Usually expressed as a percentage. It is hard to do this, but possible.
Fat burning, also does not mean fat loss. It means our body is burning fat as an energy source. It can also mean a workout we are doing is using fat as an energy source.
A healthy body burns fat at rest, even if we sat on the couch the entire day. Our resting metabolism burns carbohydrates and fats (a tiny percentage of protein also). There are scenarios in high leverage workers with high stress, where their body does not burn much fat at rest. This is fairly common in modern society, due to our lifestyles (computers, lack of sleep, stress, lights, poor diet). Understanding fat burning, and how to increase it, helps prevent this from happening. If it does happen, which is likely, we a have a backup plan to prevent weight gain.
A Quick Breakdown on Fat Burning
Again, fat on our body is a stored form of energy. It is a reserve of energy our body has stored for use at a later time.
Fat on our body, and the fat we eat is used as energy for daily metabolic functions. It is also used as an energy source during certain workouts.
Exercises like fast walking, jogging, hiking, leisurely biking, cardiovascular machines (ellipticals, recumbent bikes, etc) burn fat during the workout. This is a very direct way to increase the amount of fat we burn each day. As long as the intensity of the exercise is moderate (60-75% of our heart rate max), then we burn fat as a fuel source.
Low intensity exercise directly burns fat during the exercise bout.
Workouts like resistance training, high intensity interval training, etc. don’t use much fat during the workout. They may through more complex biological mechanisms, but they don’t directly. These types of workouts are great ways to increase the amount of calories we burn daily, through systemic changes of our body.
Higher intensity exercise and resistance training may indirectly lead to fat burning, but it’s not guaranteed. More criteria may need to be met in addition to this. Nutrition criteria and lifestyle criteria, to be specific.
How do we know what workouts burn what? We can test for this using a respiratory exchange technology called spiroergometry. We can test this in a rested state, fasted, and we can test this in an active state, during exercise.
Below, you will see an excellent example of a middle aged male, walking, then jogging, then running on a treadmill at every speed for 2 minutes. This workout lasted just under 20 minutes.
Why is this insightful? Because it provides us with a snapshot of someone’s metabolism at almost every working intensity they can muster.
This is a very common outcome from workouts like this, and provides insight into when our body’s actually burn fat during a workout.
It’s clear to see while the workout was easy (speeds < 6mph), fat metabolism peaked. Once the workout got difficult, and quite suddenly, fat metabolism declines until it basically disappears. Carbohydrate metabolism takes over from this point on.
What you need to remember:
Fat burning happens at lower intensities consistently. Despite how many times a high intensity workout is marketed as a way to burn fat, this is inaccurate, as it’s lacking additional context or criteria.
Why Fat Burning is Important to Weight Management or Weight Loss
Nutritional interventions are the main outlet for weight loss, and a very balanced diet helps target fat loss. Despite that, increasing our daily fat burn via low intensity physical activity is a safety net to ensure the weight we lose comes from fat stores.
Simply put, when we are trying to lose weight, we must eat into a caloric deficit. There are few, if any, exceptions to this rule.
Important point. Due to the imperfect nature of calculating calories, not cooking every meal, and not weighing everything we eat, it is very possible we don’t end up in a deficit as often as we plan to.
Plus, eating a weight loss diet with strict discipline is hard!
As a backup plan, if we increased our daily fat burn via low intensity exercise, or unstructured methods like walking, commuting on foot, etc. We can increase our probability of improving body composition by tapping into fat stores. We do this if the demand for fat as a fuel source, was not met by our daily nutrition.
Not only is this helpful in the present moment, but low intensity exercise develops our body’s ability to burn fat in a systemic way. This is important as people who are more efficient at burning fat are more protected against future weight gain.
Regardless of Weight Loss, Fat Loss, Body Image…
For one second, let’s throw out conversations about body image, fat stores, weight loss, fat loss, etc…
Fat burning is still a key contributor to a healthy metabolism and a long lifespan. Even if this conversation was irrelevant from a weight/ body image conversation, it is still very important characteristic for aging in a healthy way.
Increasing our body’s ability to burn fat via aerobic/ fat burning interventions is a large part of the conversation for longevity.
Most importantly, the conversation is not either/or, as in either we do resistance training and high intensity workouts OR we do low intensity training and easy workouts. The conversation is how do we mix both in consistently? Structured and unstructured!
Two key questions must be answered by our exercise program:
How can we make sure to get in 10,000 steps at low intensity to increase and improve our fat burning capacity?
Additionally, how can we do hard workouts a few times per week or more, that build muscle and develop strength?
We have to learn to develop an action plan around those two questions relentlessly. If we can do that almost every day, we are on our way to the body composition changes we want, and the lifespan we are hoping for.
What are the Action Steps from this Newsletter
We realistically have two options.
Learn to enjoy cardiovascular conditioning. Learn to enjoy it at low intensities and develop your ability to do it. Learn about heart rate zones, how to consistently hit those zones and relentlessly work at improving our capacity within these zones. If you love to run or bike, this would be easy for you.
Option 2, do the workouts you already enjoy doing. Yoga, Pilates, resistance training, sports, group fitness, whatever. Keep doing them. Additionally, figure out how you can uptick the amount of time spent on your feet walking around. Relentlessly pursue higher step counts via leisure, commuting in addition to workouts that you already enjoy doing.
This is exactly how I do it.
3-4 days per week I lift weights.
On these days I try very hard to just increase my total step count. I walk everywhere, as often as I can to increase the amount of aerobic energy I am expending. This walking drives fat burning on the same days my workouts are driving carbohydrate usage.
Sometimes on these days I do a tempo run as part of my workout as well. 1x per week.
3-4 days per week I run for endurance.
I run for 5-8 miles at 65-75% of my heart rate max.
Heart rate max = 211 - (.64 x age)
Here is the schedule I enjoy the most for my goals. My goals being to maximize the benefit of my resistance training, while also not having my legs too beat to reap the benefits of endurance training.
TLDR
Fat burning, fat losing, and weight loss all have independent definitions.
Low intensity exercise and slow twitch muscle fiber workouts burn fat during the exercise bout.
Higher intensity and resistance training workouts rely on more complex biological mechanisms to burn fat systemically over time. Other criteria needs to be in place, and this other criteria is often not met.
It’s not either/ or in regards to these two types of training, but rather, how do we fit in both in a sensible way?
I know this topic can leave a lot of unanswered questions, but feel free to comment below or send me an email if you have questions. I hope you enjoyed this week, and thanks for reading!
I cannot emphasize how incredible this article is. So easy to understand (you explained complex things in easy ways). Also great that it focuses on theory and practice: includes both the why and then the practical guidelines on how you recommend someone action the learnings from this article. I will be making changes to my routine based on this!