Tag Archive for: muscle

HIIT: Specific Fat Loss

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What were the results of HIIT training? The researchers found that there were reductions in overall weight as well as subcutaneous and visceral fat. What’s the difference? The fat just under the skin is subcutaneous fat; visceral fat is behind the abdominal muscles and around the internal organs and is more related to the development of cardiovascular disease and type 2 diabetes. There were no differences in the outcome variables with two exceptions:

  • Those who were in the running group lost a greater percentage of subcutaneous fat than the cycling group at 16.1% vs. 8.3%. The other difference was that positive changes in the microbiome were correlated with the loss of subcutaneous fat. Before you get too excited, the actual loss of subcutaneous fat was close to two pounds in the running group and about one pound in the cycling group. Still, ask your butcher for one pound of fat and see what it looks like. It’s a lot and probably worth the effort doing the HIIT program.
  • The other benefit was an improvement in some positive bacteria in the microbiome. It wasn’t associated with running or cycling; it was correlated with the loss of subcutaneous fat. It seems that visceral fat would show more benefit, but that wasn’t the case. Maybe someday we’ll find out why.

The obvious problem with doing a running HIIT program is that you have to be able to run—at least for 45 seconds. While my running is progressing slowly, I do intervals only while walking or riding the exercise bike. But running for 45 seconds? I can handle that.

Finally, while I was puzzled about the microbiome benefits, I also questioned why there was a difference between cycling and running when it came to the loss of subcutaneous fat. The researchers didn’t have a reason to explain it. I’ll give you my informed opinion: running integrates more of the core during the actual interval than cycling does. My hunch could be tested with sensors that detect the electrical activity of muscles, but that’s fine tuning that might not be necessary. As a scientist, I always want to know why, but that’s not important; it’s just important that it is.

We’ve seen that 30 minutes of moderate walking can prevent the loss of muscle and a HIIT running program can help lose subcutaneous fat in those who are overweight. How about getting fitter faster? Is that possible? Find out next week when we look at SIT training—and sitting does have something to do with it!

What are you prepared to do today?

        Dr. Chet

Reference: Med Sci Sports Exerc 2024 May 1;56(5):839-850.



HIIT and Fat Loss

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One of the “facts” exercise professionals will tell you is that there is no such thing as spot reduction; by that I mean you cannot target a specific area of your body, let’s say your abdominal area, and lose fat by doing a targeted exercise such as sit-ups or leg lifts. You can make the muscles underneath the skin stronger for sure, but there doesn’t seem to be any evidence that you can reduce the amount of fat in that area.

With 35 years of experience in the field, I would say that requires a qualified answer—it needs to be qualified with the word yet. There hasn’t been a study that proves that you can reduce fat in a specific area yet. Is it theoretically possible? Yes, I think it is. The problem is this: who would do the high quantity of exercise focused on one area long enough per workout session to do themselves any good? It may be that we’ve approached it all wrong by focusing on resistance exercise. Let’s take a look at another study that compared high-intensity interval training (HIIT) on a cycle ergometer versus a treadmill.

Researchers began with two questions. Is there any difference in the fat mass in specific areas of the body after training using a cycle ergometer (an exercise bike that measures the energy output of the cyclist) or a treadmill? In addition to that, is there any change in beneficial microbes in the microbiome after training?

Let’s take a look at what they did. Researchers recruited 16 men with a mean age of 54 and initial BMI of 29.9. After assessing initial fitness level, body fat, and body-fat distribution using the DEXA scan, and taking an initial stool sample for analysis of the microbiome, the subjects were randomly assigned to the bike or the treadmill. To make sure that there were no significant changes in diet, the subjects were required to maintain their typical diet and do seven-day diet records periodically during the study.

Think of this as intervals for the everyday exerciser. The HIIT bike program required them to do ten intervals for 45 seconds each at 80–85% of the maximal heart rate (MHR), and then a 90-second active recovery, or a HIIT running program which were nine intervals for 45 seconds at 80–85% of MHR and again with 90 seconds of recovery between intervals. They were to do this exercise under supervision three times per week for 12 weeks. The goal was to have all exercisers use the same number of calories during the workouts, whether cycling or running. The subjects were then retested to examine the differences if there were any. What did they find? I’ll tell you on Saturday.

What are you prepared to do today?

        Dr. Chet

Med Sci Sports Exerc 2024 May 1;56(5):839-850.

Spot Reduction? Maybe

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Researchers collected data from four prior studies that put a group of sedentary overweight and obese men and women on a walking program. To determine the distribution of muscle, fat, and bone, they took MRIs of their entire body. That gave the researchers not only the amount of muscle and fat mass, but exactly where that muscle and fat were located.

Once researchers assessed the fitness level of these subjects, they developed an exercise prescription for them that had them exercise at 60% to 75% of their maximal aerobic capacity for 30 minutes a session, five days a week, for six months. Their heart rates were monitored throughout the exercise session to make sure that they did not exercise above those levels; that also allowed subjects to increase the speed or grade of the treadmill as they got fitter. The subjects used a food log to track all the food they ate.

Results

Did the subjects lose some weight? Yes. Even though they were trying to maintain what they ate, they were using more calories in exercise than they had been, so they did lose some weight—in this case, just a little over two pounds in the exercising group. The controls actually gained about half a pound in the six-month study.

Now to the good stuff. The results of the MRI showed that there were definitely regional differences in skeletal mass and fat mass. As was expected, the exercising muscles, primarily the hips, thighs, and legs, saw maintenance of the skeletal muscle mass but a decrease in the fat mass. In the upper part of the body, there was a slight decrease in muscle mass in the arms and upper torso with a very slight decrease in fat mass compared to controls.

The Bottom Line

So what does this all mean? First, because the mean age was around 55, maintaining muscle mass is critical—this is the time of life when age-related muscle loss starts to occur.

Second, if this were confirmed in several clinical trials, it would mean that there should be a focus on weight training or aerobic training that utilizes the entire body. Elliptical trainers and recumbent cross trainers come to mind as something that would use both the arms and the legs, so that may be part of the solution. And from personal experience, I can say that dance classes can have a similar effect.

In order to preserve muscle mass, exercising all your muscles is important; 60 to 75% of maximal fitness would be classified as moderate exercise. That means you don’t have to kill yourself in order to obtain the benefits of regular exercise to your cardiovascular system. Add to that some weight training a few days a week, and you have your own prescription for sustaining muscle mass and maybe losing just a little bit of fat mass along the way. But what if I told you that you could increase the loss of fat mass, especially in your abdominal region, by changing up the intensity of your workouts for a few weeks? Next week’s Memos will look at that research.

What are you prepared to do today?

        Dr. Chet

Reference: MSSE. 2024. 56(5):776-782.

Is Spot Reduction Possible?

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One of the questions that I’ve thought about over the years is what happens to the skeletal muscle and fat mass in non-exercising parts of the body. If you’re a runner or a walker, what happens to your upper body? What happens to your lower body? Do you retain or even increase the muscles in your thighs and calves? Do you lose fat from your legs? How about your upper body? Do you maintain the muscle mass that you had, or do you lose some? What about the fat mass? Lose or gain?

When I was a graduate student, I ran the body composition laboratory. Over my years in the lab, I underwater weighed probably 5,000 people, from five-year-olds to 90-year-olds, from those who were underweight to morbidly obese, from tiny little gymnasts to a Big 10 hockey team. While underwater weighing was the gold standard at the time, it used some assumptions about the distribution of skeletal muscle, bones, and fat mass that weren’t as precise as they should be. These days, state-of-the-art is dual X-ray absorptiometry, which is called DEXA for short. But that doesn’t give us a precise analysis of body composition to answer those questions either.

We now have that technology in magnetic resonance imaging. Using MRI can begin to give us the answer to those questions about muscle and fat mass. Can you get rid of that stubborn belly fat? We finally may have some answers, and I’ll tell you about the latest research on Saturday.

Don’t forget to send me your list of vegetables and fruits you ate over the weekend—and remember the ketchup!

What are you prepared to do today?

        Dr. Chet

Should You Increase Your Protein Supplement?

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The research paper we’re reviewing demonstrated that there seemed to be a dose-like response to protein intake after intense exercise; that is, the more protein, the more muscle synthesis. And it lasted at least 12 hours instead of the prior four to six hours for a lower dose. Also, the excess protein intake wasn’t used to make energy to any great degree as previously thought; that means less strain on the kidneys, because when protein is broken into individual amino acids, the nitrogen group won’t have to be eliminated via the kidneys.

As always, there are more questions to be answered before this study becomes the new normal.

To Be Determined

The obvious issue is that the subjects were all young men from 18 to 40. Would the same results happen in women? And would the same result happen in older subjects, such as those in their 50s or 60s?

Next question: would the extra protein be absorbed and used the same way without the intense exercise session? The subjects did four different exercises using the legs and chest with four sets of ten reps, pushing the subjects to failure on the final three sets. Pushing yourself that hard can be challenging and even dangerous without help. Could someone with known cardiovascular disease push themselves as hard without causing a cardiovascular event? Would metabolic diseases such as type 2 diabetes impact how protein was utilized?

I could go on, but you get the point. One study with fewer than 40 young subjects, using testing procedures that will not be easy to duplicate, isn’t a basis for changing protein intake after exercise for everyone.

What Does It Mean?

The obvious answer is that it provides a new area of research. I would be most interested in how the use of essential amino acids could impact the protein synthesis in addition to additional protein intake. But let’s stick to what it means beyond future results.

On the days that you lift weights, even though perhaps not as intensely as the subjects in this study, add an additional 10 or 25 grams of protein to your post-workout shake. Milk protein was used as the source in this study, but other sources of protein powders would probably obtain the same result. The composition of protein powders doesn’t vary much, so choose whatever appeals to you.

The men began drinking their shake after they completed the exercise session. I recommend drinking extra water for a couple of hours after the shake. Do that for a specific number of weeks and see what happens. Track whether you’re able to increase weight or add muscle.

If you don’t do resistance exercise, you can see how you respond to the additional protein after a long walk or a yoga session. You might feel better with the additional protein.

The Bottom Line

Nutrition is a constantly changing field. Some basic assumptions that developed can now be reconsidered with better technology to test benefits or pitfalls. While it may take years or even decades before we have answers, what’s really important is how you respond. Adding some additional protein such as 10 or 25 grams to your morning or post-workout shake is not unreasonable to see how it benefits you. All the research in the world still comes down to how it affects you and your unique body; for example, certain antihistamines put some people to sleep and keep other people awake. As long as you’re reasonably healthy, you are your own subject.

Just remember: keep track of what you do and find a way to assess the outcome. After that, it comes down to one question: 

What are you prepared to do today?

        Dr. Chet

Reference: Cell Reports Medicine https://doi.org/10.1016/j.xcrm.2023.101324

Reconsidering Protein Supplement Amounts

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One of the basic tenets in sports nutrition is that we shouldn’t consume more than 25 grams of protein in a drink product. The reasoning has been that more won’t help you to add more muscle after a workout. This has trickled down to the point that it applies to anyone who drinks a protein shake. Based on a recent study, that may not necessarily be true.

First, let’s review why you want to build muscle. Obviously, more muscle helps you do more with your body: lift heavier objects or move your body more easily. Muscle is more dense than fat, so it takes up less space; when you are more muscular you look slimmer as well as more fit. Maybe most important, more muscle burns more calories; you can use that fact to lose weight or to eat more food.

Researchers wanted to test how long muscle synthesis would continue after an hour-long intense weight training session. The study was simple in design: take 36 young men who were physically active, test their initial exercise capacity, and then subject them to an hour-long weight training session in a laboratory setting. Afterward, in a randomized way, 12 of them got 100 grams of a protein drink, another 12 got 25 grams of the same protein drink, and the final 12 got a placebo that had no protein.

That’s where the simplicity stopped. The protein had specific quantities of carbon-labelled amino acids including leucine, the amino acid responsible for initiating protein building in muscle. The objective was to monitor whether protein synthesis lasted more than four to six hours, the previous conventional thinking. The other question is whether the excess protein would be used for making energy.

The short answer is that protein synthesis lasts at least 12 hours (and perhaps longer) at the highest intake, 100 grams. There is more to it than that, and I’ll cover it on Saturday.

What are you prepared to do today?

        Dr. Chet

Reference: Cell Reports Medicine https://doi.org/10.1016/j.xcrm.2023.101324

Your BMI and Shrinkage

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I received several interesting questions regarding the loss of height and its impact on BMI: should you use your current height or your tallest height? I checked the research and found some interesting ideas, but there’s no direct answer.

While it may change slightly over time, your current height should be used to estimate BMI. You’re measuring shorter than you were when you were younger not because you’re stooping (or melting like the Wicked Witch of the West), but because the vertebrae lose bone mass and the disks between them lose fluid and get smaller. You’ve also probably lost muscle mass, but that can be regained; when bones and discs degrade, it’s not reversible as far as we know. That may mean that a person, including yours truly, has a lower target to get to normal weight for his current height.

A new theory of obesity on Saturday.

What are you prepared to do today?

        Dr. Chet

Reference: J Am Geriatr Soc. 2012. https://doi.org/10.1111/j.1532-5415.2011.03832.x

The Key to Building Muscle

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The mega meta-analysis I talked about on Tuesday found that every combination of resistance, sets, reps, and number of days per week resulted in increased strength and increased muscle size compared to people who did nothing, but there were some combinations that provided the best results.

Finding the Best Approach to Building Muscle

Without question, lifting multiple sets with heavy weights improved strength the most. Even just one day per week showed an improvement in strength, but the most consistent results were found with at least two weight training sessions per week. What was surprising was that two sessions per week of multiple sets with light weights also saw a significant improvement in strength.

When it came to muscle hypertrophy, or more simply put, muscle size, lifting light weights for multiple sets twice per week saw the same improvement as lifting heavy weights multiple sets twice per week. That seems a little odd but may be supported by another recently published study.

In a pilot study with 22 subjects, half the group was put on a low-resistance, high-repetition weight training program while the other half was put on a more traditional heavy weight training program with fewer repetitions. The low-weight, high-repetition group performed sets of 20 to 24 repetitions, while the heavy-resistance group did the more traditional eight to 12 repetitions per set. The results showed similar benefits. There was an increase in muscle strength and muscle size in both approaches. Also the mean age of the subjects was 59 years. That eliminates the “younger people are stronger to begin with” factor.

Volitional Exertion
The pilot study reveals the key: in both approaches, the subjects were trained to push themselves to voluntary or what’s termed in the business as “volitional exertion.” It doesn’t mean barely able to lift the weight without assistance—it means that it would be a challenge to do one more repetition. It wasn’t the weight; it was the effort.

The Bottom Line

Since I talked about the 3/7 weight training program in the last Super Bowl webinar, I’ve favored that approach the most in my recommendations. It would be the low-resistance, high-repetition, two days per week approach. It seems better for beginners because even a two-pound resistance will produce results as long as they go to volitional exertion.

The author of the Washington Post article got it wrong when she said it would be easy to add muscle; it still requires consistency and effort. But it’s easier because it can be done in the comfort of your own home. Now, if we can just get everyone to do that—but that’s a challenge for another day.

What are you prepared to do today?

        Dr. Chet

References:
1. Br J Sports Med 2023;0:1–12. doi:10.1136/bjsports-2023-106807
2. Experimental Gerontology https://doi.org/10.1016/j.exger.2023.112219

Finding the Best Weight Training Program

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This year’s Super Bowl webinar on Aging with a Vengeance focused on muscle mass: hanging on to it or building it up if you’ve lost it, and how to make it happen. The fitness columnist for the Washington Post recently wrote an article on weight training that caught my attention, and I decided to take a closer look at the research behind her commentary about how easy weight training could be. There was one point that was glossed over. Let’s take a look at a recently published study that was the basis for her commentary.

Researchers decided to do what could best be described as a mega meta-analysis reviewing thousands of studies on weight training to see which type of program worked best to build strength and to increase muscle size. There were three main focal points: identify the best resistance (light, medium, or heavy weights), the best combination of sets and reps, and the number of days in a week necessary to accomplish the goals of size or strength. They found 192 studies that fit the profile for inclusion in the review. The results of their analysis were depicted in the graphs that are the graphic for this memo. Amazing.

The thickness of the lines indicates the number of studies that examined a specific type of weight training program; that gives us an indication of where the focus of research on weight training has been. In the results section, every combination of resistance, sets and reps, and days per week demonstrated some benefit. Then the researchers tried to tease out whether the use of light or heavy weight was better. I’ll talk about that on Saturday and also give you the key to determining the best weight training program.

What are you prepared to do today?

        Dr. Chet

Reference: Br J Sports Med 2023;0:1–12. doi:10.1136/bjsports-2023-106807

Protein Intake: Perspective Required

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The research paper that concluded that higher protein intake was associated with muscle loss and sarcopenia seems to offer more questions than answers. That’s actually a good thing, because future research can examine those questions. But there are questions that the researchers didn’t mention.

Researcher Observations

This is an observational study. Simply put, the subjects who completed all the tests were followed for several years, depending on when they joined the study. Therefore, no cause and effect can be inferred because the researchers were watching, not intervening.

The original number of subjects with sarcopenia was low at just 4.3%. With so many subjects over 72, the number should have been closer to 10%. The researchers acknowledged as much. If the study’s subjects had less sarcopenia than the general population, it’s hard to draw conclusions that are helpful to everyone.

My Observations

The single characteristic most closely associated with loss of muscle mass and sarcopenia was age. Protein intake was a covariate for sarcopenia but it was actually in the middle of the pack as a risk; a covariate is a separate attribute that can be measured alongside the primary variable being investigated.

The study included limited data on diet and exercise. I would expect that not very many subjects were exercising at levels high enough to sustain or increase muscle mass. That conflicts with the research data from clinical trials that show that increasing protein intake in older subjects on a weight training program increases strength and muscle mass.

What stood out more than anything was the limited amount of testing for sarcopenia and the mixed bag of testing procedures. If it’s such a problem, which every researcher in aging admits is the case, why aren’t there better diagnostic tools available to diagnose the condition? How can physicians treat a disease they aren’t diagnosing?

The Bottom Line

There is no reason to worry about protein intake as we get older based on this observational study. What we need to do is begin to retain muscle mass or reclaim our muscle through resistance training, better protein intake, and the strategic use of supplements. If you’re interested in a program to do just that, the Taking Back Your Muscle is still available on my website.

What are you prepared to do today?

        Dr. Chet

Reference: https://academic.oup.com/ageing/article/52/2/afad018/7036280