Don’t Let Your Muscles Become Marbled Like a Steak!

Yesterday was WhipperSnapper Wednesday. That was the theme of the daily email (The T2 eBlast!) that goes out to our Training Tribe members. The message was Get. Younger. Today. That was no joke and the tips and motivation the members received related to the training we are doing this month.

The month of March may not have come in like a lion, at least in terms of weather, but it started out pretty ferociously for me! I’m a perpetual student and a lifelong learner, but I tend to do the majority of my official continuing education (for my physical therapy license and various certifications) in the first quarter of every year. 

As you are probably well aware, I’ve long been an advocate of online learning opportunities. The virtual classroom may not serve every need but it’s extremely efficient for many professional conferences and classes. Since the early 2000’s I’ve always tried to do a portion of my CE work in this medium. I find it to be very convenient and cost effective.

March kicked off for me with one of the major PT conferences of the year being available in an on-demand capacity. Essentially, dozens and dozens of lectures and classes are live for the month, and the PT learner (me in this case) can study and be tested on a very flexible schedule. Not being one to waste any time, I took my first course on the first evening of the month. I’ve got about 20 sessions targeted, so I’ll basically try to get one knocked out every weekday of the month. I don’t need this many hours for CE units, as I also do other things, but I’ve definitely found some great topics in which I want to be immersed.

I think this is a good time for me to reference the title of this message. The first session I attended covered the topic of age-related sarcopenia (ARS), and it included updates from the most recent research on the subject. Sarcopenia is the term which is applied to a loss of muscle mass and strength, and to some extent, it relates to the aging process. Thus the term ARS. In very general terms, humans will lose overall strength, and to a lesser degree muscle mass or volume, through the lifespan. This phenomenon has been well-reported in the literature for quite some time. 

However, there is also an associated FATTY INFILTRATION into the muscles, which seems to be a marker of degeneration. Intermuscular (between and around different muscles) and intramuscular (among the fibers of individual muscles) adipose tissue, or fat, accumulates and increases as functional capacity and health go down. This is what the new research based on MRI cross-sections of the thigh muscles is showing. This steak-marbling condition is a telltale sign that the owner of said marbled muscle is decidedly less well-equipped in the battle against The Reaper. In other words, marbled muscle is a very strong correlate, or indicator, of morbidity.

If you picture an MRI cross-section of thigh muscles, in the simplest terms you will see muscle as a dark image and fat as a light one. Youthful, healthy muscle (even in older individuals) appears dark and solid, with very little light splotches or streaks. But the muscles of less healthy, inactive people (even those relatively young) have a much more mottled or leopard-like appearance. 

What is fascinating is the studies, when examining thigh muscles, in large numbers of subjects of nearly every age, show a powerful finding. It’s this…AGE ISN’T THE PRIMARY DETERMINANT of muscle degradation…IT’S LIFESTYLE. When examining athletic individuals who exercise regularly (more on this later), the decline of muscle quality is much less pronounced than in the general population and sedentary individuals. Older athletes, including many who are in their 70’s, actually only differ slightly with respect to muscle fiber shrinkage (reduced quantity) and fatty infiltration (reduced quality), from younger athletes, such as those in their 30’s. But equally profound and shocking is that relatively unhealthy and inactive individuals begin to experience these changes as early as in their 20’s. Metabolic health and physical fitness are really inseparable. Many young people are now showing up as clinically sarcopenic, and this is true in thin, normal body mass index (BMI), and obese individuals. 

I’d like to address that last statement. People who appear to be of low or even average bodyweight, and look somewhat “normal” in their clothing, can often have poor muscle quality and a higher percentage of bodyfat than their outer appearance may indicate. This condition has been termed “skinny fat” and I’m not keen on the term because it sounds defamatory. But it’s a real problem for undermuscled and overfat individuals. Likewise, clinically obese individuals with a BMI over 30 may appear very large (and ostensibly adequately muscled) but under MRI they may actually be relatively undermuscled for their size. And osteoporosis is strongly associated with both of the aforementioned circumstances.

The lifestyle thing is huge and it includes not just activity but nutrition, mental health, sleep, socioeconomic factors, and myriad other components. My point here is that getting healthy and high functioning requires everything, not just exercise, and we have to address each contributor to wellness for optimal results. But I’d like to talk about exercise first.

Based on my study of the literature, and my experience, I classify movement into two distinct categories: general daily activity (GDA), also known as activities of daily living, and exercise (training). 

GDA includes things like household chores, work tasks, walking to the mailbox, etc. We need a certain amount of GDA every day to maintain good health and much of this is for circulatory and metabolic homeostasis. I’ve been more specific in other presentations, but about 10 hours a week of cumulative activity is a good target for most folks. This level equates roughly to the 10,000 steps per day equivalent that is currently in vogue.

Exercise is the more purposeful form of movement for which we usually “dress out” and it includes fitness and sports training, play, and competition. The Physical Activity Guidelines for Americans recommends 150 minutes of low to moderate intensity training or 75 minutes of vigorous aerobic exercise each week, with the additional suggestion of 2 bouts of strength training and some work on mobility and balance for older individuals. In my model I round that to 3 hours total per week and blend all those elements into 3-4 weekly training sessions, each of about 45 minutes. This is a great platform for maintenance of overall health and functionality. Most of the athletes I coach do more than this level secondary to their goals and preferences.

Regarding muscles, we desperately need to avoid an isolationist, one-variable way of thinking. Explaining this point further, I want to state that our goal should not just be to keep our muscles relatively unmarbled. The Lifetime Athlete’s objective should be to maintain the highest levels of health, function, and performance capacity…for as long as possible. Everybody’s an athlete and everybody needs to adopt this position. I don’t see it any other way. Targeting one tissue, organ, or disease process isn’t enough. The organism is a whole and it must be respected in that manner.

Another major gripe I have is with exercise. Everyone is always claiming that their camp is the best and they avoid or slam another. Can’t we all just get along? It’s silly to say that you need only strength or only aerobic fitness (endurance) or only mobility. You need all that as well as speed, power, and cat-like agility. While the ratios and levels will vary from person to person, everyone should be training and maintaining all those qualities. That’s why my model strives to achieve a balance (unique and personalized) among strength, speed, power, agility, and endurance. Give up any one of those for too long and it bites you in the butt. That which you eschew, either purposely or inadvertently, becomes your achilles heel. First in performance but ultimately in function and longevity. I’m going to provide some examples of this point.

Lifters often avoid cardio because they feel it can limit their gains. But research shows that aerobic fitness supports not only health but work capacity in training. All that needs to be done is to keep it dose-specific and prioritized. Distance running isn’t a good choice for serious lifters (Olympic and Power) and bodybuilders. It’s too much pounding for big people and sends a stimulus (an epigenetic influence) for you to become a smaller version of yourself (to make overland travel more economical). But low impact training such as cycling and rowing are excellent for these athletes and I highly recommend it on a limited basis.

Sprinters are not keen on endurance work. Rightly so in some ways because this can bias the slow-twitch fibers and possibly impact speed potential. Extended amounts of steady-state jogging are not ideal training for speed athletes. But the use of tempo running and circuit training can be highly effective in helping these athletes to round out their conditioning.

Yogis often say they get all the strength they need from just doing yoga. Just ain’t true. Adding in just a smidgeon of resistance training can be very helpful in maintaining higher qualities of bone density, strength, and muscle mass. 

Runners are straight-line critters. They’ll often say they don’t need much agility, position ownership, and multidirectional movement capacity because it’s not a part of their sport. But it’s a big part of being a fully functional human and small amounts of agility-based training can be extremely beneficial.

I’m always talking about being Hard to Kill. That’s the definition of a Lifetime Athlete. You are HTK on the playing field for sure, but also in the game of LIFE. You don’t just want non-marbled muscles, you really want (and deserve) to be strong, fast, agile and durable. Not weak, slow, stiff, and fragile…which is easy to kill, representative of marbled muscles, and not far from death.

When it comes to muscle preservation, genetics and individual differences come into play significantly. Thus, dosing with exercise is not all or nothing. Levels much less than those in the Guidelines still offer benefits. I believe so strongly that we must encourage everyone to embrace any amount of exercise that is appropriate. Anything is better than nothing. We all gotta start somewhere. You can determine where you want to take it over time. But the evidence is compelling. We’ve got to preserve our muscles. And exercise is the stimulus.

Then comes nutrition. We need to consume healthy natural foods and get adequate protein. These days the convention is to target at least .7-.8 grams of protein per pound of lean body mass per day. Most thought leaders now suggest that maturing athletes need to be closer to 1 gram per pound of bodyweight per day, at least most of the time. The dietary protein provides the building blocks for muscle and other tissue (including bone) growth, repair, and maintenance. This complements the exercise stimulus.

The lifestyle support, or interventions, for muscular, and actually full-body health are equally important. Good sleep (quantity and quality), optimal stress balance, positive relationships, and so many other factors are necessary. Each individual richly deserves all these elements and to live a life of joy. 

Muscle preservation takes work. A lot of it in reality. This really should be non-negotiable. Peak performance, high quality of life, good functionality, and a long healthspan are very muscle dependent. Muscle is our greatest metabolic organ and it’s our motor for living life. Graphing out health and function over the lifespan can take two shapes. You can maintain a high, flat line until almost the end if you keep your muscles viable. Or, you can begin a gradual downward decline fairly early in life that has potentially much lower quality. With marbled muscle. The choice is yours but I want to encourage you to choose the athletic life. Most of us didn’t need more proof. But now we’ve got it.

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