How To Fight Aging With Exercise
By now, most of us have some understanding of the fact that exercise helps promote health throughout our lifespan and can protect against, or in some cases almost completely eliminate, some of the unpleasant effects associated with aging. But is there a particular way to exercise that specifically addresses the aging process? There is. Before we get there, let’s talk a little bit about what the aging process is, because in order to defeat something, you first have to first understand it.
Aging is pre-programmed in our genetic code
This seems…dumb, right? Why would we be designed to break down? The reason has to do with evolutionary biology. In order for a species to be successful, or in other words, survive, the first generation has to last long enough to ensure the survival of the second generation. Once the second generation has had children of their own, there is no evolutionary imperative for the first generation to stick around. For millions of years of human evolution, this meant that people were having children as teenagers, and then those children would have children when they were teenagers themselves, and by then the original set of parents was around 30. That’s why our genes are programmed to stop working as well by then because, from an evolutionary standpoint, we’ve done our job. There is a genetic basis for every aging related process, from reduced skin elasticity, to loss of visual acuity, to an increased tendency to store abdominal fat.
The issue, of course, is that this is completely at odds with our hopes and aspirations in the 21st century. Most of us hope to function at a high level professionally until our 60s, and then to have many more years of health and vitality to enjoy once we have retired. Why won’t our genes cooperate? Lousy genes…
The good news is, that genetic code is not an absolute, and that you can communicate with your genes through your behaviour, and this communication can actually influence genetic expression. This level of genetic code is called epigenetics. It is by understanding epigenetics that we can gear our workouts towards fighting the aging process.
The prefix epi means “on top of” or “in addition to” what we generally understand to be the basis for genetic inheritance. We know that cells divide, and pass their genetic material onto the next generation of cells. Epigenetic changes occur as a result of certain genes being turned on or off due to some environmental factor. Environmental factors can be anything from the way a person moves, thinks, eats, breathes, the company they keep, or the supplements they take. It is important to understand that literally every single aspect of your life is part of your environment. These environmental factors don’t alter the actual DNA of a cell, but they do modify the expression of various genes, and these changes can last through multiple cell divisions, and therefore significantly influence our health, our physical appearance, and much more. Strength training provides one of the best examples of how this works.
A typical adult has the genetic code to develop a certain amount of muscle mass. In the absence of strength training, it likely isn’t an overly impressive amount, but it is probably “enough.” Enough to walk, run, pick up a child, and generally do anything that you would need to do to survive. You need only look back a few generations, back when practically nobody went to the gym, or was sedentary, or ate fast food three meals a day, to see how much muscle mass a healthy adult would develop when left to their own devices. It’s really quite amazing how homogenous adult bodies were just a few decades ago.
But what if you want more muscle mass? Well, you have to convince your body that you need it, and you do that by lifting progressively heavier things. This sends a signal to your genes that says “Hey! Genes! I need more muscles! You didn’t give me enough. I am constantly in situations where I need to lift X weight and you only gave me enough muscle to lift Y so I need more! Make more muscle!” By continuously exposing yourself to conditions that require more strength, what you have effectively done is change your environment, and thus, changed the conditions required for survival.
In response to this new environment that involves regular exposure to heavy strength demands, your genes will code for new proteins that make new muscles. Of course, this is contingent on providing your body with adequate nutrition to complete the adaptation, but strength training in and of itself provides a stimulus that triggers an epigenetic response.
It’s all about Intensity
As mentioned earlier, there is a genetic basis for every aging-related process. However, we can take advantage of epigenetics to dramatically reduce the significance of some of the worst effects of aging.
Of the many variables that can be manipulated when designing an exercise program, intensity elicits the greatest epigenetic response that works against the genetic aging process.
Intensity is a broad term, but in this context, it means how hard you are working. In a strength training context, it refers to how heavy the weights are, and in an aerobic training setting, it refers to how high you get your heart rate.
As we age, we undergo an unfortunate process known as sarcopaenia, which is Latin for poverty of the flesh. Sarcopaenia describes the age-related process of muscle wasting that occurs over time. To an extent, sarcopaenia is inevitable. You simply don’t have the same robust genetic material in your 50s as you did in your 20s, and you do lose muscle mass over the course of your lifespan. Though not a disease in and of itself, it is one of the most important risk factors for frailty and associated problems such as falls, fractures, limited mobility and reduced quality of life.
We can’t eliminate sarcopaenia, but we can actively work against it by strength training, reducing its effects to the point of clinical insignificance. Our behaviour, specifically, the amount that we do or do not participate in strenuous movements, dictates the speed and magnitude of sarcopaenia that we will experience.
If you are completely sedentary, never exercising, driving to work, and only watching TV or surfing the internet in your spare time, you will undergo dramatic muscle wasting as you age. The epigenetic example explored earlier explains this. You are telling your genes that you don’t need all the nice muscles it gave you. Might as well get rid of them to preserve functional capacity for other outputs. And of course, the opposite is true.
If you were to engage in strength training regularly, you are telling your genes that, even though they may want to, that they can’t get rid of all those nice muscles that you have. I’m glossing over some critical pieces of effective exercise programming here, but if you deadlift 200 lbs every week, you will maintain the necessary strength to deadlift 200 lbs, even as you age. And a person who can deadlift 200 lbs is pretty unlikely to experience osteoporosis, or fall and break their hip later in life.
When it comes to shocking your genes into action, more is definitely more. The training adaptations that occur when you increase your maximum strength from 100 lbs to 200 lbs have a more potent anti aging effect than if you increase your ability to lift 100 lbs from ten repetitions to twenty. Training to lift 200 lbs vs 100 lbs elicits a greater anti-aging response than training to lift 100 lbs 20 times instead of 10 times due to the nature of the required output. Lifting more weight requires better motor unit recruitment and increased strength of the working muscle and related connective tissues.
In an aerobic training example, intensity again elicits a more powerful anti-aging epigenetic response. Improving your 3k time will have a greater effect on the aging process than training your ability to run 20k vs 10k. Running faster, rather than farther, results in an increased number of capillaries in your muscles, more mitochondria in each cell, increased cardiac output, and the ability to maintain a high heart rate. This last example is particularly interesting.
Consider that the formula for calculating resting heart rate is 220 beats per minute minus your age. Though subject to a large degree of variability, the structure of this equation tells us that maximum heart rate generally decreases across the life span. Maximum heart rate is a measure of cardiac output and functional capacity, or in other words, your ability to do physical work. Regularly getting your heart rate elevated through intervals, sprints, or even circuit training slows the age-related decline in maximum heart rate by communicating with your genes that you still require the ability to achieve a high heart rate in your environment.
It is important to reconcile the general recommendation of “exercise intensity fights the aging process” with the needs of the individual. If you are a healthy 20 something, you can probably modify your workouts to get ahead of the aging process without significant risk, but if you are older and perhaps already have a risk factor such as high blood pressure, then talk to your doctor or work with a Certified Exercise Physiologist before modifying your exercise routine.
Furthermore, though intense exercise has the greatest impact on decreasing age-related decline in functional capacity, it’s not the only way. Regular walking goes a long way to preserving health related quality of life, and an evening stretching ritual, or regularly doing yoga can help maintain tissue elasticity and maintain functional mobility throughout the lifespan. But if you want to stay strong, lean, powerful, and athletic into your later years, structure your training to focus on working hard, lifting heavy, and moving fast.