Are You Strong Enough?
When I started my journey of exploring my own physical potential through strength and fitness training, one of the things that impressed me the most was learning just how weak I was. One of the things that impresses me the most now, nearly two years later, is how much that has changed.
So, it’s strange to hear a sedentary person (usually a male over 60 years old) say, “Oh, I think I’m already strong enough?”
It brings up the question, how strong is strong enough?
And how do you know when you’re strong enough?
Well, you can figure this out.
But first I have to point out that there are two potential strategies for aging. The first is to decide what you want to be able to do and put effort (and strategy) into doing it. The second is to decide to give up the activity and do something easier.
If you’re using the second strategy you don’t need to read the rest of this article.
So let’s say you want to be able to climb stairs and in order to do so you’ll need to be able to generate a force of 2 Watts per kilogram of body weight in leg extension (this example and its language are borrowed from the book Bending the Aging Curve by Joseph Signorile).
If you have the ability to generate 4 watts per kilogram of body weight then you have a physical reserve of 2 W/kg.
“Physical reserve can be defined as the difference between a person’s maximal capacity and the minimal capacity required to perform a specific task or maintain a specific level of activity” ~Joseph Signorile
However if you can only generate 2.2 W/kg of body weight then your physical reserve is far lower at 0.2 W/kg of body weight.
Add to this that your ability to generate force will decline with each rep (each stair in this case) as your muscles fatigue, and that there will be further fatigue with each set of repetitions (each trip up and down the flight of stairs).
It’s important that your maximal capacity exceeds the minimal capacity needed to perform the task. If your maximal capacity is equal to the task. Then you will be completely exhausted to the point of muscular failure (not rupture, just the end of the ability to generate any more force until you’ve had a recovery period) once you get to the top of the stairs.
Frailty increases as physical reserves decrease.
Stated another way, the greater your physical reserves (for instance, if you can generate 8W/kg of body weight in leg extension), the more activity you can perform. That means that as your physical reserves increase relative to the task you want to perform you will move along the continuum of function away from being Frail or Dependent (the lowest level of function) and toward Fully Fit and Athletic.
Now, let’s say that currently you can generate about 2.5 W/kg of body weight in leg extension, so you can get up the stairs with near maximal effort. But if you get sick and need bed rest for several weeks. Or rather than getting sick, you get knee surgery, or you trip and land on your knee and feel like you need to stay off it so you can recover.
The loss of conditioning that will take place in the muscles that create leg extension during your recovery will likely place you below the threshold of the 2 W/kg needed to climb the stairs.
It is important for your physical reserves to exceed the desired task by a significant amount to account for periods of injury, surgery or sickness. You might feel like having enough strength to get up the stairs is fit enough, but if you have strength and then some, you will make it through a phase of injury without having your basic function compromised, and that will make it much easier to regain your preinjury level of conditioning.
What if you want to do more than make it up and down a flight of stairs? What if you want to climb mountains? Or go nordic skiing? Or engage in paddle sports, long bike rides, marathons?
As we age it becomes harder to maintain our physical conditioning. Each time you unpack your hiking legs after a long winter of disuse you will have lost function. Without training, over the winter your physical reserves will have decreased.
To do a quick test of your physical reserves right now kneel down like you are about to propose marriage and then stand up. Try to do it without using your hands. Try and think of all the activities that you engage in or would like to engage where having the ability to easily stand up from a kneeling position would be useful. What comes to mind for me is tying my shoe, picking something up off the floor, gardening, looking at a bug or a flower, stepping up onto a big rock…
So, how strong is strong enough?
Strong enough is having a physical reserve that exceeds the amount needed to maintain the most challenging activities and do the most challenging tasks that you want to do.
If you don’t have that strength and those physical reserves then start training, because you can change that.
