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: muscle loss

How to lose weight effectively

In order to lose weight, you must eat at a caloric deficit (consume less calories than you burn). In other words, over a period of time, say, 3 months to reach a weight goal, most days should be focused on eating less calories than your body burns for energy. This puts you at a negative energy balance.

A negative energy balance promotes the catabolism of your own tissues. In other words, your body begins to break down its own tissues to be used for energy. Sounds great right? Well, what most people don't realize is that although you are losing adipose tissue (body fat) during times of catabolism, you will lose some muscle mass as well (fat-free mass).

A study in Advances in Nutrition looked at how catabolism works and how our dietary choices affect what tissues are being catabolized:

Skeletal Muscle Responses to Negative Energy Balance: Effects of Dietary Protein
Sustained periods of negative energy balance decrease body mass due to losses of both fat and skeletal muscle mass. Decreases in skeletal muscle mass are associated with a myriad of negative consequences, including suppressed basal metabolic rate, decreased protein turnover, decreased physical performance, and increased risk of injury. Decreases in skeletal muscle mass in response to negative energy balance are due to imbalanced rates of muscle protein synthesis and degradation. However, the underlying physiological mechanisms contributing to the loss of skeletal muscle during energy deprivation are not well described. Recent studies have demonstrated that consuming dietary protein at levels above the current recommended dietary allowance (0.8 g·kg−1·d−1) may attenuate the loss of skeletal muscle mass by affecting the intracellular regulation of muscle anabolism and proteolysis. However, the specific mechanism by which increased dietary protein spares skeletal muscle through enhanced molecular control of muscle protein metabolism has not been elucidated. This article reviews the available literature related to the effects of negative energy balance on skeletal muscle mass, highlighting investigations that assessed the influence of varying levels of dietary protein on skeletal muscle protein metabolism. Further, the molecular mechanisms that may contribute to the regulation of skeletal muscle mass in response to negative energy balance and alterations in dietary protein level are described.

To summarize:

Sustained periods of negative energy balance decrease body mass due to losses of both fat and skeletal muscle mass

Mentioned above. If you eat less than you burn, your body will begin to look inward for energy. This is not a perfect system. Ideally, your body would burn only adipose tissue and leave your muscles alone, but sadly, that is not the case.

In general, the proportion of body mass loss at the recommended dietary allowance of protein (0.8 g·kg−1·d−1) is: ~75% adipose tissue and ~25% fat-free mass

So, if you were to consume protein at a "standard" dietary recommendation of 0.8g/kgxday (so that would be 65g protein for a 180lb person), then you will lose approximately 75% adipose to 25% muscle. In other words, every 10lbs you lose, 7.5lbs of that would be body fat and 2.5lbs would be muscle.

Consuming a high-protein diet may contribute to the regulation of muscle mass by maintaining whole-body protein turnover in response to either acute or prolonged periods of negative energy balance

Researchers have determined that consuming a diet higher in protein than the recommended 0.8g/kgxday can actually help to tip those numbers towards preserving even more muscle mass when at an overall caloric deficit.

A high protein diet during most studies was 1.5 g·kg−1·d−1, nearly twice the recommended dietary allowance of 0.8 g·kg−1·d−1

We're still not talking about crazy-high amounts of protein here, that is still only 123g of protein for a 180lb person.

Leucine-containing food products during exercise stimulate the mTORC1 pathway, increasing muscle protein synthesis and decreased whole-body proteolysis

So, foods containing the branch chain amino acid (BCAA) leucine have shown positive effects of further maintaining muscle mass, so make sure if you are eating at a caloric deficit, to make sure every one of those calories that you do ingest count, by loading up on leucine sources.

Recommended leucine intake is currently 14 mg·kg−1·d−1, but the amount required to maximize the stimulation of muscle anabolic intracellular signaling may be at least 40–65 mg·kg−1·d−1, and even up to 7–12 g·d−1 to contribute to the preservation of muscle mass during stressors such as energy restriction

Summary

You can use dietary means to try and reverse some of the effects of muscle breakdown during weight loss. I would also recommend adding resistance training to target all areas of the body to "signal" the body, letting it know that your muscles are being used and are needed. This will also help not only preserve muscle, but to preserve strength as well, as your goal of losing weight is pursued.





Does muscle burn fat?

Well, sort of.  Technically muscles burn calories, but it is complicated...

To be honest, I see fitness enthusiasts and Beachbody Coaches using this phrase all the time. Note, there is a vast  difference between a fitness enthusiast and a fitness professional, so be careful what knowledge you are gaining from every individual.

Anyways, saying "muscle burns fat" is like saying "my car burns oxygen". Both are correct statements, but they can be misleading. 

Body fat, also known as adipose tissue serves many functions in the human body. Insulation and energy are its primary functions. To be honest, the body doesn't really like, or want to carry around more weight than it has to, but because our bodies have evolved to also not want to waste or lose too much energy, you end up storing a lot of your extra calories away when you over eat. 

To be honest, muscles' energy 'currency' of choice is something called glycogen. Glycogen is a readily-available energy source stored in the muscle cells as well as the liver. When you perform high-intensity muscle contractions, such as resistance training, your muscles are using glycogen. 

Adipose tissue is more of a slow-burning fuel source because oxygen has to be present during the metabolic process in order for it to be a viable and useful energy source. For example, when you are out for a leisurely walk, your breathing and heart rate are more than capable of keeping up with your cells' oxygen demands, so your primary fuel source is usually adipose.

Having said that, a leisurely walk doesn't really require a whole lot of caloric expenditure, so intense exercise is definitely the way to go if you are trying to maintain a healthy body weight. So how does muscle burn fat exactly? 

Well, as I said before, muscle actually burns glycogen in intense circumstances. It is a quick and fast-burning energy source. But, when intense exercise is over, your body goes into a state known as EPOC (excess post-exercise oxygen consumption) . Think of a sprinter like Usain Bolt. During his 9 seconds of sprinting, he, along with his competitors are probably either holding their breath, or breathing at a pretty normal rate. This is because the body is using anaerobic means to fuel its muscles. Once the race is over, however, their bodies go into EPOC mode. During the post-race interviews, that is when you see them huffing and puffing as they try and replenish those used energy stores.

That  is when adipose tissue is used as fuel by your muscles.

So what advantages can we learn from all of this? 

First of all, the fitter you become, aka, the more efficient your body is at utilizing stored energy reserves, the more effective it will become at using stored adipose as a primary energy source.

Secondly, even though your muscles don't directly burn adipose, intensity is definitely the name of the game. An intense, efficient, and effective resistance workout is the best way to go to maintain a healthy weight, as EPOC, as well as micro trauma in the muscle fibers can cause a spike in metabolism and calorie burn for up to 72 hours following a workout.





Strength and Conditioning Tips

I have compiled a helpful list of training tips below that I am sure everyone can learn something from, enjoy!

Training Time

This tip is actually a twofer (broken into 2 parts). Men and women alike are always asking when the best time of the day is to work out, so that is why this is broken into two. For men (generalizing here), they want to know when the best time of day is to work out to grow big, strong muscles. Many people will tell you that working out in the afternoon or evening is the best time for muscle growth for a number of reasons, but simply is not true. The Journal for Strength and Conditioning Research has said that consistency is the key here. If you only have time to hit the weights in the morning, do that! The study showed that men made equal strength gains regardless of what time of day they worked out.

Similarly, women (again, generalizing) want to know when the best time of day is to exercise to burn fat. Again, consistency is the key. There are pros and cons to exercising either morning or night. For example, exercising in the morning can rev your metabolism for the rest of the day, whereas exercising in the evening has the potential to burn more calories as your body's metabolism is potentially at its highest. As I have said before, doingsomething is always better than doing nothing, so if you only have time in the morning to exercise, do that! I personally exercise in the morning because that's what fits my schedule, but if it doesn't suit you, then fine!

Pack on the Protein

I see this one time and time again. People think that in order to grow big, strong muscles, they need to cram as much protein into each meal as possible. Studies have shown that eating 30 grams of protein in a meal yields the same benefits of eating 90 grams does. This is a perfect example of "more isn't necessarily better". Instead, you should aim to have protein in small doses throughout the day. Keep one thing in mind, however. Protein seems to have this aura attached to it now that it is this wonderful "weight-loss" food. Protein still has calories, and ingesting too much protein can still result in unwanted body fat if unused, so make sure your diet is properly proportioned. Not only that, but if all you are doing is eating protein all day, you will likely be missing out on important vitamins and nutrients that can only be found in whole grains, fruits, and vegetables!

Muscle Loss

For the longest time, there was this belief that as people age, their muscle tissue decreases. This is in fact true, but this is a sort of chicken-and-egg problem. Does your muscle tissue disappear because you age, or because you stop using your muscles as you age? Studies are now showing that it is in fact possible to continue muscle growth with strength improvements later in life. Yes, men have lowered testosterone as they age, but there is more to it than that. Once you hit the age of 65, sure, you may not be making major muscle gains, but you can still use resistance training to reduce the loss of muscle. Not only that, men and women can greatly benefit from resistance training throughout life to help strengthen bones, muscles and connective tissues!

Do It For Your Brain

Sure, many people like to exercise to try and look a certain way. Unfortunately, many personal trainers will market these types of things to you as well. I have a swift kick of reality for you though. Unless you have tremendous genetics, or photoshop (or a combination of the two), you are never going to look like some of those models or Hollywood celebrities. Not only that, but chasing "the perfect image" will only end in disappointment and despair. Instead, you should exercise to feel better about yourself in your own skin, not to mention the mental and body benefits that comes along with it. Think of how great you feel after a good workout. Wouldn't that be great to bottle that up and take a swig of that every day for the rest of your life?

Go Fast and then Go Home

I probably sound like a broken record here, but unfortunately some people just don't get it. I see and get asked by people all the time why they are not getting/seeing results from working out an hour or more at a time. I then see them slowing jogging on a treadmill or elliptical. Instead, why not try HIIT (high-intensity interval training) and cut your workout times in half? Chronic cardio should only be used if you are training for...wait for it...a cardio event such as a marathon or triathlon, etc. Instead, most people can get into their gym, exercise using HIIT principles for 20-30mins and then be done with an even better workout than something that takes twice the time.

A study done by McMaster University in Hamilton found that men who performed sprint interval training for a total of 2.5 hours (including recovery) over the course of 2 weeks has the same results as the group who performed endurance training for a total of 10.5 hours over the same time period. Yes, its alright to go back and read that again. 1/5th of the time for the same results! Another study following a group of 15 women found that high-intensity exercise (40 to 45 minutes approximately four times weekly at a mean HR of 163 bpm) reduced body fat by about 5 percent over the course of 15 weeks versus a virtually unchanged percentage in the group that performed exercise at a lower heart rate (132 beats per minute).