I consider the preservation and enhancement of muscular strength to be one of the most important goals a human being should set at any stage of life. Lack of adequate muscle mass and function is one of the single greatest contributors to poor quality of life and accelerated aging.
This study in particular is mind blowing since it is powerful evidence that strength training can actually turn back time and make you younger. The study looked at nearly 600 different age-related genes that control energy production from the mitochondria (our cell's power generators), and muscle weakness.associated with aging. After older study participants underwent 6 months of resistance training, their genes markedly reverted back to a considerably younger profile.
Resistance training genetically turned back the physiological hands of time…a veritable fountain of youth!
Now think of how all of us age. We start off as children who walk, run and jump often, although that is becoming less the case in today's children who are hooked on screen play over outdoor play. Then we become predominantly walkers maybe with some running. Then we become mostly walkers, with a steady drop in walking speed and stability until we eventually require an assistive device (cane, walker, wheelchair, etc.). A loss of leg strength and balance can finally culminate in a fall, leading to a fractured hip or some other serious injury, causing us to become bed bound.
This dismal deterioration in movement skills can be largely blamed on our increasing neglect on preserving and enhancing muscle strength as we age. Multiple studies show that loss of leg strength is strongly correlated with chronic disease, disability and death, in addition to being linked to reduced brain/cognitive abilities as shown in this study.
To be blunt, weaker muscles, particularly leg muscles, make you dumber, more diseased, more disabled and dependent on assisted devices (canes, walkers, wheelchairs, etc) and human beings.
What do I mean by human beings? Individuals with weaker legs become so weak and ill, that often they require caretakers or family members have to spend time assisting with daily tasks. I've seen this in so many families.
Apart from health, imagine the financial consequences of having to hire a full time caretaker or a family member having to cut back on work to take care of a weakened individual. All of this could have been completely prevented if this person payed attention to leg strength and balance.
This is why I say that when an individual neglects their health, they ignore the health of everyone around them. Family members who become caregivers (and caregivers in general) have high rates of depression and chronic disease.
My commitment to my own leg strength and overall health has many incentives, and one of the greatest ones is avoiding a future where I become dependent on my family to care for me.
I don't want to become a physical, emotional and/or financial burden to them. Hopefully I got your attention. Let's now discuss the science of these all important muscles while I also provide practical advice on preserving their structure and function as we age.
For those of you familiar with my book, online talks and programs, you should understand the concept of muscle capacity or what I refer to as “muscle parking space.” Watch the short 18 second video clip from my Whole Family Wellness Program which shows how glucose enters the muscle cell (aka “muscle parking lot”) by presenting the insulin (aka “parking pass”) at the surface cell receptor (aka “parking gate”).
I use these types of animations (with audio) in my program to educate families, including kids/teens about complex concepts like insulin resistance and how to prevent or reverse these processes with proven lifestyle solutions.
Muscles store carbohydrates/glucose in a form called muscle glycogen. Humans typically have ~400-500 grams of muscle glycogen parking space. The storage capacity is typically greater in men vs women and in those who are regularly active and include weight/resistance training as part of their exercise regimen.
If you are consuming carbohydrates on a daily basis that exceeds your muscle parking lot capacity, your muscles will divert the incoming glucose to other parking lots like fat tissue and liver, which in turn leads to obesity, fatty liver and elevated blood lipids.
When you spend most of your day sitting, you rapidly lose muscle strength and mass. In other words your parking capacity shrinks and now you have less storage space for carbohydrates. This is the case I see in most of the patients in my clinic. They seem content with their 3-4 gym sessions a week where they walk on a treadmill or elliptical, hardly producing any reasonable muscular fatigue.
Although this more casual approach to exercise is better than nothing, it is not doing a sufficient job of increasing muscle parking space, especially given the typical volume of carbohydrates they are consuming daily.
When you think of where your largest parking lots are located, they are in your lower extremities.
To sufficiently expand parking space to accommodate a little, but not excessive amounts of carbohydrates, you must apply focused and intensive training that involves your legs.
Think squats, lunges, walking/running inclines, etc. to a point that produces sufficient muscular fatigue, not just a little soreness.
I see many patients who tell me they can't train their legs due to knee pain. I will do a separate blog post on knee pain but can tell you the vast majority of knee pain I see in the clinic results from prolonged sitting and insufficient engagement and training of lower leg muscles. This includes single leg, asymmetric exercises. When patients improve the strength in their legs, invariably knee pain disappears or improves significantly.
Avoiding leg exercises because of knee pain will lead to further deterioration in leg muscle strength which in turn will turn intermittent knee pain into chronic and eventually crippling knee pain. Although there may have been a trigger event like an injury or process likely early arthritis to produce your initial knee pain, I strongly believe that in most individuals who have chronic or worsening knee pain, it is due to rapidly deteriorating quadriceps (thigh muscle) strength.
Now stepping back for a moment, what is the overall metabolic significance of knee pain? Knee pain automatically limits your physical activity, which leads to gradual muscle atrophy in your affected leg (s), which are your critical larger capacity glucose parking lots. This in turn puts you at risk for insulin resistance especially if your carb intake is excessive (not enough muscular parking space to store those carbs), in addition to progressive physical disability. I hope this motivates you to take that annoying twinge or ache in your pain more seriously!
If you had a specific injury or serious damage to tendons and/or cartilage you need to work with your physician/specialist and an experienced physical therapist to design the right type of exercises to increase strength without worsening your pain.
Aside from increasing muscle parking space, you also need to improve muscle output. What do I mean by muscle output? As nutrients like glucose and fats (aka “fatty acids”) enter muscle cells, you would like a significant portion of these nutrients to be converted to energy (aka “ATP”).
See another 10 second video from Whole Family Wellness below that shows you how inside active muscle cells, glucose “cars” are converted into ATP energy by our mitochondrial power stations.
Glucose cars not sufficiently converted to ATP energy will prematurely fill your muscle parking lots. If your muscle parking lot capacity is limited because you don't regularly train your muscles and stay active, this filling point will occur earlier.
Fatty acids in particular, that are not used for energy, may actually trigger insulin resistance. From the above short video, think of these unused fatty acids as disrupting the downstream signaling mechanisms of the insulin receptor that allow glucose to enter into the cell. It's a complex process, so let's explore further in a future post.
Now how do we ensure that glucose and fatty acids are diverted more towards energy production and not towards overfilling parking space and poisoning insulin receptor activity respectively?
Your muscles need to be sufficiently physically active throughout the day by avoiding prolonged sitting and aiming for 8,000-10,000 steps daily. You also need to make sure you exercise and train your muscles, especially larger muscle groups (think legs and core), regularly through a mixture of strength and endurance exercises.
Improved cardiovascular conditioning, strength and increased baseline physical activity helps divert more incoming nutrients to energy production and less towards overfilling glucose parking lots or interrupting insulin signaling mechanisms. So now you understand how exercise increases muscle capacity (parking lot space) and output (energy conversion).
Many of my patients hope and pray they can achieve all of their health goals strictly through diet and lowering carb intake, but if you want to truly reverse insulin resistance and chronic disease, and extend lifespan while maintaining independence, quality of life, and brain function (aka “health span”), you absolutely cannot do it without exercise.
Although I'm careful not to injure myself with exercise as I age, I find specific ways to challenge myself even more to compensate for the age-related muscle loss. Don't stick to the same, mundane workout routine day after day, week after week. I'll do my best to share some of my techniques on social medial when I can.
Muscle Fiber Type
I want to take a few moments to review muscle fiber types. I'll use some athletic examples to help make this information stick, but keep in mind that the deterioration of specific muscle fiber types with aging, predisposes us to increased disability and fall risk, so I'll explain that at the end of this section.
Human beings carry 3 major muscle fiber types: Type 1, Type 2A and Type 2B. Type 1 muscle fibers help fuel lower intensity, higher endurance activities like distance running, Type 2Bs are for high intensity, short duration activities like sprinting, while Type 2A falls somewhere in between.
Genes and the type of exercise training you perform help determine which types of fibers are better developed for each individual. Eliud Kipchoge, the world's greatest marathoner, has incredibly well developed Type 1 muscle fibers. If you haven't watched the documentary, “Breaking 2” where he tries to break the unthinkable 2 hour mark for a marathon, I strongly recommend watching it here. Such a feat has long been considered humanly impossible.
In terms of the ultimate Type 2B fiber athlete, you don't need to look any further than Usain Bolt, unquestionably the greatest sprinter who has ever lived. Now, what about the intermediate Type 2A athlete? This would be an individual who can deftly combine sprinting and endurance into events like the 4oom or 800m.
Usain Bolt's powerful Type 2Bs won't be able to push him to a gold medal in the 400m or 800m because they are designed for shorter distances. For the world's greatest Type 2A athlete, I'd look to Wade Van Niekerk who ran the most incredible 400m race ever witnessed, found here. I've watched this race countless times and it blows me away every single time!
Now let's step away from these incredible athletes and return to us mortals. As we age, the first type of muscle fiber we lose out are the fast twitch, Type 2B “Usain Bolt” fibers. You may ask me why you would need to have the fast twitch fibers of a sprinter if all you do is sit in front of a computer all day and just do some cardio for workouts?
Picture walking down the street and your foot suddenly hits an uneven surface. You miss a step while going down a flight of stairs. You go for a casual bike ride and a car swerves in front of you. You are skiing down a slope when a snowboarder cuts you off. You try to avoid colliding into your grandchild who sprints past you. It's your Type 2B rapid response muscle fibers that respond instantly to help you regain balance and prevent a serious fall leading to an injury. As we all know, everyday life does not take place on smooth, symmetrical and predictable surfaces.
Inevitably we'll face a situation that requires us to activate those Type 2B fibers and they are the exact fiber type that deteriorates the most rapidly as we age.
Aside from being our injury-prevention muscle fibers, these precious Type 2Bs also are also referred to as “Fast twitch glycolytic,” where glycolytic means these fibers are adept at burning glucose for energy. For those of you struggling with blood glucose issues, developing your Type 2Bs can be powerful allies in the fight against developing diabetes.
Weight/resistance training and performing faster paced exercises like HIIT training (high intensity interval training) help preserve our Type 2B fibers. For seniors and those completely new to weight training, start with machines, since they are safer for novices than free weights. Prioritize large muscle groups like legs, back, chest, core and shoulders. Once you develop a good foundation of strength, you can start using some free weights, but do start with lighter weights so your form is impeccable.
I'm also a big fan of slow weight training which can produce rapid muscular fatigue in less time. Dr.Doug McGuff has a great workout called “The Big 5” which is summarized nicely in this post and outlined in greater detail in his book Body by Science. This is one of many different approaches I use in the gym to challenge my muscles in various, time efficient ways. Read my part 2 blog post on exercise here which emphasizes some of my favorite body weight exercises that set the foundation for strength and fitness. After you have these moves down, you can safely increase weight/resistance and challenge your body in various ways.
Finally, there is no rule saying that only young children are permitted to jump and run as fast as they can. Right now if you're in a safe environment and you don't have a limiting condition, I want you to jump up and down as high as you can 3 times. If you feel hesitant or unstable, do a mini-jump just a few inches off the ground. Was that so hard? Don't let physical age limit you. Jump for joy! Below is a picture of me a little overzealously jumping during a dance ritual with an African tribe in Tanzania. You can clearly see how awestruck the tribe members are at my vertical leap! 🙂
As a side note, I've always been fascinated by why certain ethnicities excel in track and field, while others do not. For example, is there a genetic reason why South Asians, who represent a quarter of the world's population, don't medal in sprinting? You might argue a lack of resources and infrastructure to support athletes, but we can make the same argument for countries like Africa who put out world class distance runners and Jamaica who produces incredible male and female sprinters. Clearly genes play some role.
In my research, I started exploring the ACTN3 gene which codes for the alpha-actinin 3 protein, a special breed of fast twitch fibers found in most sprinters, jumpers and throwers. I wondered if maybe Asian Indians might be deficient in this gene and sure enough I came across the 23&Me report below. The T variant of this special gene represents a mutation where the sprinting/jumping/throwing is not expressed, meaning you lack these special track and field super powers.
Now look at the graph below and notice which ethnic group has the greatest percent of this mutation? That's right. South Asians! Which ethnic group has the lowest frequency of the mutated gene, meaning more of the functional copy? That's right. African Americans. I'm not saying this is the sole explanation for our relative lack of speed and vertical leap distance. South Asians don't typically emphasize exercise and athletics as a priority, so the combination of our sedentary behavior on top of a genetic deficiency may explain why you don't see Asian Indians on the Track and Field medal stands at the Olympics. I also wonder if a relative deficiency of these fibers may impair our ability to burn sugar effectively and further predispose us to diabetes, but I would not consider this a major contributing factor.
Aside from implementing the right dose of resistance and interval training to improve muscular capacity and output, be sure you are not shortchanging protein in your diet. Doing the required physical work without sufficient protein will significantly impair your body's ability to recover from workouts and to build strong, new muscles. Read my prior post on protein power here, which includes a link to my dedicated protein post for vegetarians here.
Aging leads to a very slow and natural decline in muscle mass and function. Our modern, sedentary lifestyle has greatly accelerated this decline and we are already seeing its effects, even in youth. We must counteract the collective atrophy in muscle strength which contributes to an increasingly rapid deterioration of our mental, physical, and metabolic health. We, as a society, are becoming weaker and more physically dependent as we age.
If you or a loved one is unmotivated to push themselves beyond their limits, you need to take further action by possibly hiring a trainer or someone who can provide safe motivation and guidance. I did this with my own mother as I described here. This may cost you, but I can't think of many investments that can actually improve quality of life and partially reverse the aging process.